TY  - JOUR
A1  - Bloethe, Jan H.
A1  - Munack, Henry
A1  - Korup, Oliver
A1  - Fuelling, Alexander
A1  - Garzanti, Eduardo
A1  - Resentini, Alberto
A1  - Kubik, Peter W.
T1  - Late Quaternary valley infill and dissection in the Indus River, western Tibetan Plateau margin
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
N2  - The Indus, one of Earth's major rivers, drains large parts of the NW Himalaya and the Transhimalayan ranges that form part of the western Tibetan Plateau margin. In the western Himalayan syntaxis, where local topographic relief exceeds 7 km, the Indus has incised a steep bedrock gorge at rates of several mm yr(-1). Upstream, however, the upper Indus and its tributaries alternate between bedrock gorges and broad alluvial flats flanked by the Ladakh and Zanskar ranges. We review the late Quaternary valley history in this region with a focus on the confluence of the Indus and Zanskar Rivers, where vast alluvial terrace staircases and lake sediments record major episodes of aggradation and incision. New absolute dating of high-level fluvial terrace remnants using cosmogenic Be-10, optically and infrared stimulated luminescence (OSL, IRSL) indicates at least two phases of late Quaternary valley infilling. These phases commenced before similar to 200 ka and similar to 50-20 ka, judging from terrace treads stranded >150 m and similar to 30-40 m above modern river levels, respectively. Numerous stacks of lacustrine sediments that straddle the Indus River >200 km between the city of Leh and the confluence with the Shyok River share a distinct horizontal alignment. Constraints from IRSL samples of lacustrine sequences from the Leh-Spituk area reveal a protracted lake phase from >177 ka to 72 ka, locally accumulating >50-m thick deposits. In the absence of tectonic faulting, major lithological differences, and stream capture, we attribute the formation of this and other large lakes in the region to natural damming by large landslides, glaciers, and alluvial fans. The overall patchy landform age constraints from earlier studies can be reconciled by postulating a major deglacial control on sediment flux, valley infilling, and subsequent incision that has been modulated locally by backwater effects of natural damming. While comparison with Pleistocene monsoon proxies reveals no obvious correlation, a lateor post-glacial sediment pulse seems a more likely source of this widespread sedimentation that has partly buried the dissected bedrock topography. Overall, the long residence times of fluvial, alluvial and lacustrine deposits in the region (>500 ka) support previous studies, but remain striking given the dominantly steep slopes and deeply carved valleys that characterise this high-altitude mountain desert. Recalculated late Quaternary rates of fluvial bedrock incision in the Indus and Zanskar of 1.5 +/- 0.2 mm yr(-1) are at odds with the longevity of juxtaposed valley-fill deposits, unless a lack of decisive lateral fluvial erosion helps to preserve these late Pleistocene sedimentary archives. We conclude that alternating, similar to 10(4)-yr long, phases of massive infilling and incision have dominated the late Quaternary history of the Indus valley below the western Tibetan Plateau margin. (C) 2014 Elsevier Ltd. All rights reserved.
KW  - Himalaya
KW  - Indus
KW  - Valley fills
KW  - Glaciation
KW  - Erosion
KW  - Lake sediment
Y1  - 2014
U6  - https://doi.org/10.1016/j.quascirev.2014.04.011
SN  - 0277-3791
VL  - 94
SP  - 102
EP  - 119
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Blöthe, Jan H.
A1  - Rosenwinkel, Swenja
A1  - Hoeser, Thorsten
A1  - Korup, Oliver
T1  - Rock-glacier dams in High Asia
JF  - Earth surface processes and landforms : the journal of the British Geomorphological Research Group
N2  - Rock glaciers in semiarid mountains contain large amounts of ice and might be important water stores aside from glaciers, lakes, and rivers. Yet whether and how rock glaciers interact with river channels in mountain valleys remains largely unresolved. We examine the potential for rock glaciers to block or disrupt river channels, using a new inventory of more than 2000 intact rock glaciers that we mapped from remotely sensed imagery in the Karakoram (KR), Tien Shan (TS), and Altai (ALT) mountains. We find that between 5% and 14% of the rock glaciers partly buried, blocked, diverted or constricted at least 95 km of mountain rivers in the entire study area. We use a Bayesian robust logistic regression with multiple topographic and climatic inputs to discern those rock glaciers disrupting mountain rivers from those with no obvious impacts. We identify elevation and potential incoming solar radiation (PISR), together with the size of feeder basins, as dominant predictors, so that lower-lying and larger rock glaciers from larger basins are more likely to disrupt river channels. Given that elevation and PISR are key inputs for modelling the regional distribution of mountain permafrost from the positions of rock-glacier toes, we infer that river-blocking rock glaciers may be diagnostic of non-equilibrated permafrost. Principal component analysis adds temperature evenness and wet-season precipitation to the controls that characterise rock glaciers impacting on rivers. Depending on the choice of predictors, the accuracy of our classification is moderate to good with median posterior area-under-the-curve values of 0.71-0.89. Clarifying whether rapidly advancing rock glaciers can physically impound rivers, or fortify existing dams instead, deserves future field investigation. We suspect that rock-glacier dams are conspicuous features that have a polygenetic history and encourage more research on the geomorphic coupling between permafrost lobes, river channels, and the sediment cascades of semiarid mountain belts. (c) 2018 John Wiley & Sons, Ltd.
KW  - rock glaciers
KW  - natural dams
KW  - sediment flux
KW  - Bayesian logistic regression
KW  - High Asia
Y1  - 2018
U6  - https://doi.org/10.1002/esp.4532
SN  - 0197-9337
SN  - 1096-9837
VL  - 44
IS  - 3
SP  - 808
EP  - 824
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Blöthe, Jan Henrik
A1  - Korup, Oliver
T1  - Millennial lag times in the Himalayan sediment routing system
JF  - Earth & planetary science letters
N2  - Any understanding of sediment routing from mountain belts to their forelands and offshore sinks remains incomplete without estimates of intermediate storage that decisively buffers sediment yields from erosion rates, attenuates water and sediment fluxes, and protects underlying bedrock from incision. We quantify for the first time the sediment stored in > 38000 mainly postglacial Himalayan valley fills, based on an empirical volume-area scaling of valley-fill outlines automatically extracted from digital topographic data. The estimated total volume of 690(+452/-242) km(3) is mostly contained in few large valley fills > 1 km(3), while catastrophic mass wasting adds another 177(31) km(3). Sediment storage volumes are highly disparate along the strike of the orogen. Much of the Himalaya's stock of sediment is sequestered in glacially scoured valleys that provide accommodation space for similar to 44% of the total volume upstream of the rapidly exhuming and incising syntaxes. Conversely, the step-like long-wave topography of the central Himalayas limits glacier extent, and thus any significant glacier-derived storage of sediment away from tectonic basins. We show that exclusive removal of Himalayan valley fills could nourish contemporary sediment flux from the Indus and Brahmaputra basins for > 1 kyr, though individual fills may attain residence times of > 100 kyr. These millennial lag times in the Himalayan sediment routing system may sufficiently buffer signals of short-term seismic as well as climatic disturbances, thus complicating simple correlation and interpretation of sedimentary archives from the Himalayan orogen, its foreland, and its submarine fan systems. (C) 2013 Elsevier B.V. All rights reserved.
KW  - sediment storage
KW  - Himalayas
KW  - sediment budget
KW  - tectonic geomorphology
KW  - geomorphometry
Y1  - 2013
U6  - https://doi.org/10.1016/j.epsl.2013.08.044
SN  - 0012-821X
SN  - 1385-013X
VL  - 382
IS  - 20
SP  - 38
EP  - 46
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Blöthe, Jan Henrik
A1  - Korup, Oliver
A1  - Schwanghart, Wolfgang
T1  - Large landslides lie low: Excess topography in the Himalaya-Karakoram ranges
JF  - Geology
N2  - Mass wasting is an important process for denuding hillslopes and lowering ridge crests in active mountain belts such as the Himalaya-Karakoram ranges (HKR). Such a high-relief landscape is likely to be at its mechanical threshold, maintained by competing rapid rock uplift, river incision, and pervasive slope failure. We introduce excess topography, Z(E), for quantifying potentially unstable rock-mass volumes inclined at angles greater than a specified threshold angle. We find that Z(E) peaks along major fluvial and glacial inner gorges, which is also where the majority of 492 large (>0.1 km(2)) rock-slope failures occur in the Himalaya's largest cluster of documented Pleistocene to Holocene bedrock landslides. Our data reveal that bedrock landslides in the HKR chiefly detached from near or below the median elevation, whereas glaciers and rock glaciers occupy higher-elevation bands almost exclusively. Less than 10% of the area of the HKR is upslope of glaciers, such that possible censoring of evidence of large bedrock landslides above the permanent snow line barely affects this finding. Bedrock landslides appear to preferentially undermine topographic relief in response to fluvial and glacial incision along inner gorges, unless more frequent and smaller undetected failures, or rigorous (peri-)glacial erosion, compensate for this role at higher elevation. Either way, the distinct patterns of excess topography and large bedrock landsliding in the HKR juxtapose two stacked domains of landslide and (peri-)glacial erosion that may respond to different time scales of perturbation. Our findings call for more detailed analysis of vertical erosional domains and their geomorphic coupling in active mountain belts.
Y1  - 2015
U6  - https://doi.org/10.1130/G36527.1
SN  - 0091-7613
SN  - 1943-2682
VL  - 43
IS  - 6
SP  - 523
EP  - 526
PB  - American Institute of Physics
CY  - Boulder
ER  - 
TY  - BOOK
A1  - Davies, Tim R.
A1  - Korup, Oliver
A1  - Clague, John J.
T1  - Geomorphology and natural hazards
BT  - understanding landscape change for disaster mitigation
T3  - Advanced textbook series
N2  - "In spite of ever-increasing research into natural hazards, the reported damage from natural disasters continues to rise, increasingly disrupting human activities. We, as scientists who study the way in which the part of Earth most relevant to society- the surface-behaves, are disturbed and frustrated by this trend. It appears that the large amounts of funding devoted each year to research into reducing the impacts of natural disasters could be much more effective in producing useful results. At the same time we are aware that society, as represented by its decision makers, while increasingly concerned at the impacts of natural disasters on lives and economies, is reluctant to acknowledge the intrinsic activity of Earth's surface and to take steps to adapt societal behaviour to minimise the impacts of natural disasters. Understanding and managing natural hazards and disasters are beyond matters of applied earth science, and also involve considering human societal, economic and political decisions"
Y1  - 2021
SN  - 978-1-119-99031-4
SN  - 978-1-118-64861-2
PB  - Wiley
CY  - Hoboken, NJ
ER  - 
TY  - JOUR
A1  - Dosseto, Anthony
A1  - May, Jan-Hendrik
A1  - Choi, Jeong-Heon
A1  - Swander, Zachary J.
A1  - Fink, David
A1  - Korup, Oliver
A1  - Hesse, Paul
A1  - Singh, Tejpal
A1  - Mifsud, Charles
A1  - Srivastava, Pradeep
T1  - Late quaternary fluvial incision and aggradation in the Lesser Himalaya, India
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
N2  - Reconstructing how rivers respond to changes in runoff or sediment supply by incising or aggrading has been pivotal in gauging the role of the Indian Summer Monsoon (ISM) as a geomorphic driver in the Himalayas. Here we present new chronological data for fluvial aggradation and incision from the Donga alluvial fan and the upper Alaknanda River, as well as a compilation of previous work. In addition to conventional OSL-SAR (Single-Aliquot Regenerative-Dose) dating method, we have tested and applied pulsed OSL (POSL) dating for quartz samples that include K-rich feldspar inclusions, which is expected to improve the applicability and validity of OSL ages in the Lesser Himalaya. For previously dated deposits, our OSL ages are shown to be systematically older than previously reported ages. These results suggest periods of aggradation in the Alaknanda and Dehradun Valleys mainly between similar to 25 and 35 ka. This most likely reflects decreased stream power during periods of weakened monsoon. In addition, in-situ cosmogenic beryllium-10 was used to infer bedrock surface exposure ages, which are interpreted as episodes of active fluvial erosion. Resulting exposure ages span from 3 to 6 ka, suggesting that strath terraces were exposed relatively recently, and incision was dominant through most of the Holocene. In combination, our results support precipitation-driven fluvial dynamics, which regulates the balance between stream power and sediment supply. On a larger spatial scale, however, fluvial dynamics are probably not spatially homogeneous as aggradation could have been taking place in adjacent catchments while incision dominated in the study area. (C) 2018 Elsevier Ltd. All rights reserved.
Y1  - 2018
U6  - https://doi.org/10.1016/j.quascirev.2018.07.035
SN  - 0277-3791
VL  - 197
SP  - 112
EP  - 128
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Drewes, Julia
A1  - Moreiras, Stella
A1  - Korup, Oliver
T1  - Permafrost activity and atmospheric warming in the Argentinian Andes
JF  - Geomorphology : an international journal on pure and applied geomorphology
N2  - Rock glaciers are permafrost or glacial landforms of debris and ice that deform under the influence of gravity. Recent estimates hold that, in the semiarid Chilean Andes for example, active rock glaciers store more water than glaciers. However, little is known about how many rock glaciers might decay because of global warming and how much this decay might contribute to water and sediment release. We investigated an inventory of >6500 rock glaciers in the Argentinian Andes, spanning the climatic gradient from the Desert Andes to cold-temperate Tierra del Fuego. We used active rock glaciers as a diagnostic of permafrost, assuming that the toes mark the 0 degrees C isotherm in climate scenarios for the twenty-first century and their impact on freezing conditions near the rock glacier toes. We find that, under future worst case warming, up to 95% of rock glaciers in the southern Desert Andes and in the Central Andes will rest in areas above 0 degrees C and that this freezing level might move up more than twice as much (similar to 500 m) as during the entire Holocene (similar to 200 m). Many active rock glaciers are already well below the current freezing level and exemplify how local controls may confound regional prognoses. A Bayesian Multifactor Analysis of Variance further shows that only in the Central Andes are the toes of active rock glaciers credibly higher than those of inactive ones. Elsewhere in the Andes, active and inactive rock glaciers occupy indistinguishable elevation bands, regardless of aspect, the formation mechanism, or shape of rock glaciers. The state of rock glacier activity predicts differences in elevations of toes to 140 m at best so that regional inference of the distribution of discontinuous permafrost from rock-glacier toes cannot be more accurate than this in the Argentinian Andes. We conclude that the Central Andes-where rock glaciers are largest, cover the most area, and have a greater density than glaciers-is likely to experience the most widespread disturbance to the thermal regime of the twenty-first century. (C) 2018 Elsevier B.V. All rights reserved.
KW  - rock glacier
KW  - Argentina
KW  - permafrost
KW  - climate change
Y1  - 2018
U6  - https://doi.org/10.1016/j.geomorph.2018.09.005
SN  - 0169-555X
SN  - 1872-695X
VL  - 323
SP  - 13
EP  - 24
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Fan, Xuanmei
A1  - Scaringi, Gianvito
A1  - Korup, Oliver
A1  - West, A. Joshua
A1  - van Westen, Cees J.
A1  - Tanyas, Hakan
A1  - Hovius, Niels
A1  - Hales, Tristram C.
A1  - Jibson, Randall W.
A1  - Allstadt, Kate E.
A1  - Zhang, Limin
A1  - Evans, Stephen G.
A1  - Xu, Chong
A1  - Li, Gen
A1  - Pei, Xiangjun
A1  - Xu, Qiang
A1  - Huang, Runqiu
T1  - Earthquake-Induced Chains of Geologic Hazards
BT  - Patterns, Mechanisms, and Impacts
JF  - Reviews of geophysics
N2  - Large earthquakes initiate chains of surface processes that last much longer than the brief moments of strong shaking. Most moderate‐ and large‐magnitude earthquakes trigger landslides, ranging from small failures in the soil cover to massive, devastating rock avalanches. Some landslides dam rivers and impound lakes, which can collapse days to centuries later, and flood mountain valleys for hundreds of kilometers downstream. Landslide deposits on slopes can remobilize during heavy rainfall and evolve into debris flows. Cracks and fractures can form and widen on mountain crests and flanks, promoting increased frequency of landslides that lasts for decades. More gradual impacts involve the flushing of excess debris downstream by rivers, which can generate bank erosion and floodplain accretion as well as channel avulsions that affect flooding frequency, settlements, ecosystems, and infrastructure. Ultimately, earthquake sequences and their geomorphic consequences alter mountain landscapes over both human and geologic time scales. Two recent events have attracted intense research into earthquake‐induced landslides and their consequences: the magnitude M 7.6 Chi‐Chi, Taiwan earthquake of 1999, and the M 7.9 Wenchuan, China earthquake of 2008. Using data and insights from these and several other earthquakes, we analyze how such events initiate processes that change mountain landscapes, highlight research gaps, and suggest pathways toward a more complete understanding of the seismic effects on the Earth's surface.
KW  - earthquake-induced landslides
KW  - debris flows
KW  - geohazards
KW  - landscape evolution
KW  - sediment cascade
KW  - continental earthquakes
Y1  - 2019
U6  - https://doi.org/10.1029/2018RG000626
SN  - 8755-1209
SN  - 1944-9208
VL  - 57
IS  - 2
SP  - 421
EP  - 503
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Fan, Xuanmei
A1  - van Westen, Cees J.
A1  - Korup, Oliver
A1  - Gorum, Tolga
A1  - Xu, Qiang
A1  - Dai, Fuchu
A1  - Huang, Runqiu
A1  - Wang, Gonghui
T1  - Transient water and sediment storage of the decaying landslide dams induced by the 2008 Wenchuan earthquake, China
JF  - Geomorphology : an international journal on pure and applied geomorphology
N2  - Earthquake-triggered landslide dams are potentially dangerous disrupters of water and sediment flux in mountain rivers, and capable of releasing catastrophic outburst flows to downstream areas. We analyze an inventory of 828 landslide dams in the Longmen Shan mountains, China, triggered by the M-w 7.9 2008 Wenchuan earthquake. This database is unique in that it is the largest of its kind attributable to a single regional-scale triggering event: 501 of the spatially clustered landslides fully blocked rivers, while the remainder only partially obstructed or diverted channels in steep watersheds of the hanging wall of the Yingxiu-Beichuan Fault Zone. The size distributions of the earthquake-triggered landslides, landslide dams, and associated lakes (a) can be modeled by an inverse gamma distribution; (b) show that moderate-size slope failures caused the majority of blockages; and (c) allow a detailed assessment of seismically induced river-blockage effects on regional water and sediment storage. Monte Carlo simulations based on volumetric scaling relationships for soil and bedrock failures respectively indicate that 14% (18%) of the estimated total coseismic landslide volume of 6.4 (14.6) x 10(9) m(3) was contained in landslide dams, representing only 1.4% of the >60,000 slope failures attributed to the earthquake. These dams have created storage capacity of similar to 0.6x 10(9) m(3) for incoming water and sediment. About 25% of the dams containing 2% of the total river-blocking debris volume failed one week after the earthquake; these figures had risen to 60% (similar to 20%), and >90% (>90%) within one month, and one:year, respectively, thus also emptying similar to 92% of the total potential water and sediment storage behind these, dams within one year following the earthquake. Currently only similar to 0.08 x 10(9) m(3) remain available as natural reservoirs for storing water and sediment, while similar to 0.19 x 10(9) m(3), i.e. about a third of the total river-blocking debris volume, has been eroded by rivers. Dam volume and upstream catchment area control to first order the longevity of the barriers, and bivariate domain plots are consistent with the observation that most earthquake-triggered landslide dams were ephemeral. We conclude that the river-blocking portion of coseismic slope failures disproportionately modulates the post-seismic sediment flux in the Longmen Shan on annual to decadal timescales.
KW  - Landslide dam
KW  - Earthquake
KW  - Magnitude and frequency
KW  - Sediment budget
Y1  - 2012
U6  - https://doi.org/10.1016/j.geomorph.2012.05.003
SN  - 0169-555X
VL  - 171
SP  - 58
EP  - 68
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - GEN
A1  - Fischer, Melanie
A1  - Brettin, Jana
A1  - Roessner, Sigrid
A1  - Walz, Ariane
A1  - Fort, Monique
A1  - Korup, Oliver
T1  - Rare flood scenarios for a rapidly growing high-mountain city: Pokhara, Nepal
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Pokhara (ca. 850 m a.s.l.), Nepal's second-largest city, lies at the foot of the Higher Himalayas and has more than tripled its population in the past 3 decades. Construction materials are in high demand in rapidly expanding built-up areas, and several informal settlements cater to unregulated sand and gravel mining in the Pokhara Valley's main river, the Seti Khola. This river is fed by the Sabche glacier below Annapurna III (7555 m a.s.l.), some 35 km upstream of the city, and traverses one of the steepest topographic gradients in the Himalayas. In May 2012 a sudden flood caused >70 fatalities and intense damage along this river and rekindled concerns about flood risk management. We estimate the flow dynamics and inundation depths of flood scenarios using the hydrodynamic model HEC-RAS (Hydrologic Engineering Center’s River Analysis System). We simulate the potential impacts of peak discharges from 1000 to 10 000 m3 s−1 on land cover based on high-resolution Maxar satellite imagery and OpenStreetMap data (buildings and road network). We also trace the dynamics of two informal settlements near Kaseri and Yamdi with high potential flood impact from RapidEye, PlanetScope, and Google Earth imagery of the past 2 decades. Our hydrodynamic simulations highlight several sites of potential hydraulic ponding that would largely affect these informal settlements and sites of sand and gravel mining. These built-up areas grew between 3- and 20-fold, thus likely raising local flood exposure well beyond changes in flood hazard. Besides these drastic local changes, about 1 % of Pokhara's built-up urban area and essential rural road network is in the highest-hazard zones highlighted by our flood simulations. Our results stress the need to adapt early-warning strategies for locally differing hydrological and geomorphic conditions in this rapidly growing urban watershed.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1284 
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-571209
SN  - 1866-8372
IS  - 1284
SP  - 3105
EP  - 3123
ER  - 
TY  - JOUR
A1  - Fischer, Melanie
A1  - Brettin, Jana
A1  - Roessner, Sigrid
A1  - Walz, Ariane
A1  - Fort, Monique
A1  - Korup, Oliver
T1  - Rare flood scenarios for a rapidly growing high-mountain city: Pokhara, Nepal
JF  - Natural Hazards and Earth System Sciences
N2  - Pokhara (ca. 850 m a.s.l.), Nepal's second-largest city, lies at the foot of the Higher Himalayas and has more than tripled its population in the past 3 decades. Construction materials are in high demand in rapidly expanding built-up areas, and several informal settlements cater to unregulated sand and gravel mining in the Pokhara Valley's main river, the Seti Khola. This river is fed by the Sabche glacier below Annapurna III (7555 m a.s.l.), some 35 km upstream of the city, and traverses one of the steepest topographic gradients in the Himalayas. In May 2012 a sudden flood caused >70 fatalities and intense damage along this river and rekindled concerns about flood risk management. We estimate the flow dynamics and inundation depths of flood scenarios using the hydrodynamic model HEC-RAS (Hydrologic Engineering Center’s River Analysis System). We simulate the potential impacts of peak discharges from 1000 to 10 000 m3 s−1 on land cover based on high-resolution Maxar satellite imagery and OpenStreetMap data (buildings and road network). We also trace the dynamics of two informal settlements near Kaseri and Yamdi with high potential flood impact from RapidEye, PlanetScope, and Google Earth imagery of the past 2 decades. Our hydrodynamic simulations highlight several sites of potential hydraulic ponding that would largely affect these informal settlements and sites of sand and gravel mining. These built-up areas grew between 3- and 20-fold, thus likely raising local flood exposure well beyond changes in flood hazard. Besides these drastic local changes, about 1 % of Pokhara's built-up urban area and essential rural road network is in the highest-hazard zones highlighted by our flood simulations. Our results stress the need to adapt early-warning strategies for locally differing hydrological and geomorphic conditions in this rapidly growing urban watershed.
Y1  - 2022
U6  - https://doi.org/10.5194/nhess-22-3105-2022
SN  - 1684-9981
VL  - 22
SP  - 3105
EP  - 3123
PB  - Copernicus Publications
CY  - Katlenburg-Lindau
ET  - 9
ER  - 
TY  - GEN
A1  - Fischer, Melanie
A1  - Korup, Oliver
A1  - Veh, Georg
A1  - Walz, Ariane
T1  - Controls of outbursts of moraine-dammed lakes in the greater Himalayan region
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Glacial lakes in the Hindu Kush–Karakoram–Himalayas–Nyainqentanglha (HKKHN) region have grown rapidly in number and area in past decades, and some dozens have drained in catastrophic glacial lake outburst floods (GLOFs). Estimating regional susceptibility of glacial lakes has largely relied on qualitative assessments by experts, thus motivating a more systematic and quantitative appraisal. Before the backdrop of current climate-change projections and the potential of elevation-dependent warming, an objective and regionally consistent assessment is urgently needed. We use an inventory of 3390 moraine-dammed lakes and their documented outburst history in the past four decades to test whether elevation, lake area and its rate of change, glacier-mass balance, and monsoonality are useful inputs to a probabilistic classification model. We implement these candidate predictors in four Bayesian multi-level logistic regression models to estimate the posterior susceptibility to GLOFs. We find that mostly larger lakes have been more prone to GLOFs in the past four decades regardless of the elevation band in which they occurred. We also find that including the regional average glacier-mass balance improves the model classification. In contrast, changes in lake area and monsoonality play ambiguous roles. Our study provides first quantitative evidence that GLOF susceptibility in the HKKHN scales with lake area, though less so with its dynamics. Our probabilistic prognoses offer improvement compared to a random classification based on average GLOF frequency. Yet they also reveal some major uncertainties that have remained largely unquantified previously and that challenge the applicability of single models. Ensembles of multiple models could be a viable alternative for more accurately classifying the susceptibility of moraine-dammed lakes to GLOFs.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1160 
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-522050
SN  - 1866-8372
ER  - 
TY  - JOUR
A1  - Fischer, Melanie
A1  - Korup, Oliver
A1  - Veh, Georg
A1  - Walz, Ariane
T1  - Controls of outbursts of moraine-dammed lakes in the greater Himalayan region
JF  - The Cryosphere
N2  - Glacial lakes in the Hindu Kush–Karakoram–Himalayas–Nyainqentanglha (HKKHN) region have grown rapidly in number and area in past decades, and some dozens have drained in catastrophic glacial lake outburst floods (GLOFs). Estimating regional susceptibility of glacial lakes has largely relied on qualitative assessments by experts, thus motivating a more systematic and quantitative appraisal. Before the backdrop of current climate-change projections and the potential of elevation-dependent warming, an objective and regionally consistent assessment is urgently needed. We use an inventory of 3390 moraine-dammed lakes and their documented outburst history in the past four decades to test whether elevation, lake area and its rate of change, glacier-mass balance, and monsoonality are useful inputs to a probabilistic classification model. We implement these candidate predictors in four Bayesian multi-level logistic regression models to estimate the posterior susceptibility to GLOFs. We find that mostly larger lakes have been more prone to GLOFs in the past four decades regardless of the elevation band in which they occurred. We also find that including the regional average glacier-mass balance improves the model classification. In contrast, changes in lake area and monsoonality play ambiguous roles. Our study provides first quantitative evidence that GLOF susceptibility in the HKKHN scales with lake area, though less so with its dynamics. Our probabilistic prognoses offer improvement compared to a random classification based on average GLOF frequency. Yet they also reveal some major uncertainties that have remained largely unquantified previously and that challenge the applicability of single models. Ensembles of multiple models could be a viable alternative for more accurately classifying the susceptibility of moraine-dammed lakes to GLOFs.
Y1  - 2020
U6  - https://doi.org/10.5194/tc-15-4145-2021
SN  - 1994-0416
VL  - 15
PB  - Copernicus Publications
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Gorum, Tolga
A1  - Korup, Oliver
A1  - van Westen, Cees J.
A1  - van der Meijde, Mark
A1  - Xu, Chong
A1  - van der Meer, Freek D.
T1  - Why so few? Landslides triggered by the 2002 Denali earthquake, Alaska
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
N2  - The 2002 M-w 7.9 Denali Fault earthquake, Alaska, provides an unparalleled opportunity to investigate in quantitative detail the regional hillslope mass-wasting response to strong seismic shaking in glacierized terrain. We present the first detailed inventory of similar to 1580 coseismic slope failures, out of which some 20% occurred above large valley glaciers, based on mapping from multi-temporal remote sensing data. We find that the Denali earthquake produced at least one order of magnitude fewer landslides in a much narrower corridor along the fault ruptures than empirical predictions for an M 8 earthquake would suggest, despite the availability of sufficiently steep and dissected mountainous topography prone to frequent slope failure. In order to explore potential controls on the reduced extent of regional coseismic landsliding we compare our data with inventories that we compiled for two recent earthquakes in periglacial and formerly glaciated terrain, i.e. at Yushu, Tibet (M-w 6.9, 2010), and Aysen Fjord, Chile (2007 M-w 6.2). Fault movement during these events was, similarly to that of the Denali earthquake, dominated by strike-slip offsets along near-vertical faults. Our comparison returns very similar coseismic landslide patterns that are consistent with the idea that fault type, geometry, and dynamic rupture process rather than widespread glacier cover were among the first-order controls on regional hillslope erosional response in these earthquakes. We conclude that estimating the amount of coseismic hillslope sediment input to the sediment cascade from earthquake magnitude alone remains highly problematic, particularly if glacierized terrain is involved. (C) 2014 Elsevier Ltd. All rights reserved.
KW  - Earthquake
KW  - Landslide
KW  - Glacial
KW  - Sediment cascade
KW  - Denali
KW  - Alaska
Y1  - 2014
U6  - https://doi.org/10.1016/j.quascirev.2014.04.032
SN  - 0277-3791
VL  - 95
SP  - 80
EP  - 94
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Gorum, Tolga
A1  - van Westen, Cees J.
A1  - Korup, Oliver
A1  - van der Meijde, Mark
A1  - Fan, Xuanmei
A1  - van der Meer, Freek D.
T1  - Complex rupture mechanism and topography control symmetry of
 mass-wasting pattern, 2010 Haiti earthquake
JF  - GEOMORPHOLOGY
N2  - The 12 January 2010 M-w 7.0 Haiti earthquake occurred in a complex deformation zone at the boundary between the North American and Caribbean plates. Combined geodetic, geological and seismological data posited that surface deformation was driven by rupture on the Leogane blind thrust fault, while part of the rupture occurred as deep lateral slip on the Enriquillo-Plantain Garden Fault (EPGF). The earthquake triggered >4490 landslides, mainly shallow, disrupted rock falls, debris-soil falls and slides, and a few lateral spreads, over an area of similar to 2150 km(2). The regional distribution of these slope failures defies those of most similar earthquake-triggered landslide episodes reported previously. Most of the coseismic landslides did not proliferate in the hanging wall of the main rupture, but clustered instead at the junction of the blind Leogane and EPGF ruptures, where topographic relief and hillslope steepness are above average. Also, low-relief areas subjected to high coseismic uplift were prone to lesser hanging wall slope instability than previous studies would suggest. We argue that a combined effect of complex rupture dynamics and topography primarily control this previously rarely documented landslide pattern. Compared to recent thrust fault-earthquakes of similar magnitudes elsewhere, we conclude that lower static stress drop, mean fault displacement, and blind ruptures of the 2010 Haiti earthquake resulted in fewer, smaller, and more symmetrically distributed landslides than previous studies would suggest. Our findings caution against overly relying on across-the-board models of slope stability response to seismic ground shaking. (C) 2012 Elsevier B.V. All rights reserved.
KW  - Landslide
KW  - Earthquake
KW  - Thrust fault
KW  - Fault rupture dynamics
KW  - Topography
KW  - Haiti
Y1  - 2013
U6  - https://doi.org/10.1016/j.geomorph.2012.11.027
SN  - 0169-555X
VL  - 184
SP  - 127
EP  - 138
PB  - ELSEVIER SCIENCE BV
CY  - AMSTERDAM
ER  - 
TY  - JOUR
A1  - Günther, Oliver
A1  - Schüle, Manja
A1  - Zurell, Damaris
A1  - Jeltsch, Florian
A1  - Roeleke, Manuel
A1  - Kampe, Heike
A1  - Zimmermann, Matthias
A1  - Scholz, Jana
A1  - Engbert, Ralf
A1  - Elsner, Birgit
A1  - Schlangen, David
A1  - Agrofylax, Luisa
A1  - Georgi, Doreen
A1  - Weymar, Mathias
A1  - Wagener, Thorsten
A1  - Bookhagen, Bodo
A1  - Eibl, Eva P. S.
A1  - Korup, Oliver
A1  - Oswald, Sascha
A1  - Thieken, Annegret
A1  - van der Beek, Peter
T1  - Portal Wissen = Exzellenz
JF  - Portal Wissen: Das Forschungsmagazin der Universität Potsdam
N2  - Was nicht nur gut oder sehr gut ist, nennen wir gern exzellent. Aber was meint das eigentlich? Vom lateinischen „excellere“ kommend, beschreibt es Dinge, Personen oder Handlungen, die „hervor-“ oder „herausragen“ aus der Menge, sich „auszeichnen“ gegenüber anderen. Mehr geht nicht. Exzellenz ist das Mittel der Wahl, wenn es darum geht, der Erste oder Beste zu sein. Und das macht auch vor der Forschung nicht halt. Wer auf die Universität Potsdam schaut, findet zahlreiche ausgezeichnete Forschende, hervorragende Projekte und immer wieder auch aufsehenerregende Erkenntnisse, Veröffentlichungen und Ergebnisse.
Aber ist die UP auch exzellent? Eine Frage, die 2023 ganz sicher andere Wellen schlägt als vielleicht vor 20 Jahren. Denn seit dem Start der Exzellenzinitiative 2005 gelten als – wörtlich – exzellent jene Hochschulen, denen es gelingt, in dem umfangreichsten Förderprogramm für Wissenschaft in Deutschland einen Zuschlag zu erhalten. Egal ob in Form von Graduiertenschulen, Forschungsclustern oder – seit Fortsetzung des Programms ab 2019 unter dem Titel „Exzellenzstrategie“ – ganzen Exzellenzuniversitäten: Wer im Kreis der Forschungsuniversitäten zu den Besten gehören will, braucht das Siegel der Exzellenz. In der gerade eingeläuteten neuen Wettbewerbsrunde der „Exzellenzstrategie des Bundes und der Länder“ bewirbt sich die Universität Potsdam mit drei Clusterskizzen um Förderung.
Ein Antrag kommt aus der Ökologie- und Biodiversitätsforschung. Ziel ist es, ein komplexes Bild ökologischer Prozesse zu zeichnen – und dabei die Rolle von einzelnen Individuen ebenso zu betrachten wie das Zusammenwirken vieler Arten in einem Ökosystem, um die Funktion der Artenvielfalt genauer zu bestimmen. Eine zweite Skizze haben die Kognitionswissenschaften eingereicht. Hier soll das komplexe Nebeneinander von Sprache und Kognition, Entwicklung und Lernen sowie Motivation und Verhalten als dynamisches Miteinander erforscht werden – wobei auch mit den Erziehungswissenschaften kooperiert wird, um verknüpfte Lernund Bildungsprozesse stets mitzudenken. Der dritte Antrag aus den Geo- und Umweltwissenschaften nimmt extreme und besonders folgenschwere Naturgefahren und -prozesse wie Überschwemmungen und Dürren in den Blick. Die Forschenden untersuchen die Extremereignisse mit besonderem Fokus auf deren Wechselwirkung mit der Gesellschaft, um mit ihnen einhergehende Risiken und Schäden besser einschätzen sowie künftig rechtzeitig Maßnahmen einleiten zu können.
„Alle drei Anträge zeichnen ein hervorragendes Bild unserer Leistungsfähigkeit“, betont der Präsident der Universität, Prof. Oliver Günther, Ph.D. „Die Skizzen dokumentieren eindrucksvoll unser Engagement, vorhandene Forschungsexzellenz sowie die Potenziale der Universität Potsdam insgesamt. Allein die Tatsache, dass sich drei schlagkräftige Konsortien in ganz unterschiedlichen Themenbereichen zusammengefunden haben, zeigt, dass wir auf unserem Weg in die Spitzengruppe der deutschen Universitäten einen guten Schritt vorangekommen sind.“
In diesem Heft schauen wir, was sich in und hinter diesen Anträgen verbirgt: Wir haben mit den Wissenschaftlerinnen und Wissenschaftlern gesprochen, die sie geschrieben haben, und sie gefragt, was sie sich vornehmen, sollten sie den Zuschlag erhalten und ein Cluster an die Universität holen. Wir haben aber auch auf die Forschung geschaut, die zu den Anträgen geführt hat und die schon länger das Profil der Universität prägt und ihr national wie international Anerkennung eingebracht hat. Wir stellen eine kleine Auswahl an Projekten, Methoden und Forschenden vor, um zu zeigen, warum in diesen Anträgen tatsächlich exzellente Forschung steckt! Übrigens: Auch „Exzellenz“ ist nicht das Ende der Fahnenstange. Immerhin lässt sich das Adjektiv exzellent sogar steigern. In diesem Sinne wünschen wir exzellentestes Vergnügen beim Lesen!
T3  - Portal Wissen: Das Forschungsmagazin der Universität Potsdam [Deutsche Ausgabe] - 02/2023 
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-611440
SN  - 2194-4245
IS  - 02/2023
ER  - 
TY  - JOUR
A1  - Günther, Oliver
A1  - Schüle, Manja
A1  - Zurell, Damaris
A1  - Jeltsch, Florian
A1  - Roeleke, Manuel
A1  - Kampe, Heike
A1  - Zimmermann, Matthias
A1  - Scholz, Jana
A1  - Mikulla, Stefanie
A1  - Engbert, Ralf
A1  - Elsner, Birgit
A1  - Schlangen, David
A1  - Agrofylax, Luisa
A1  - Georgi, Doreen
A1  - Weymar, Mathias
A1  - Wagener, Thorsten
A1  - Bookhagen, Bodo
A1  - Eibl, Eva P. S.
A1  - Korup, Oliver
A1  - Oswald, Sascha
A1  - Thieken, Annegret
A1  - van der Beek, Peter
T1  - Portal Wissen = Excellence
JF  - Portal Wissen: The research magazine of the University of Potsdam
N2  - When something is not just good or very good, we often call it excellent. But what does that really mean? Coming from the Latin word “excellere,” it describes things, persons, or actions that are outstanding or superior and distinguish themselves from others. It cannot get any better. Excellence is the top choice for being the first or the best. Research is no exception.
At the university, you will find numerous exceptional researchers, outstanding projects, and, time and again, sensational findings, publications, and results. But is the University of Potsdam also excellent? A question that will certainly create a different stir in 2023 than it did perhaps 20 years ago. Since the launch of the Excellence Initiative in 2005, universities that succeed in winning the most comprehensive funding program for research in Germany have been considered – literally – excellent. Whether in the form of graduate schools, research clusters, or – since the program was continued in 2019 under the title “Excellence Strategy” – entire universities of excellence: Anyone who wants to be among the best research universities needs the seal of excellence.
The University of Potsdam is applying for funding with three cluster proposals in the recently launched new round of the “Excellence Strategy of the German Federal and State Governments.” One proposal comes from ecology and biodiversity research. The aim is to paint a comprehensive picture of ecological processes by examining the role of single individuals as well as the interactions among many species in an ecosystem to precisely determine the function of biodiversity. A second proposal has been submitted by the cognitive sciences. Here, the complex coexistence of language and cognition, development and learning, as well as motivation and behavior will be researched as a dynamic interrelation. The projects will include cooperation with the educational sciences to constantly consider linked learning and educational processes. The third proposal from the geo and environmental sciences concentrates on extreme and particularly devastating natural hazards and processes such as floods and droughts. The researchers examine these extreme events, focusing on their interaction with society, to be able to better assess the risks and damages they might involve and to initiate timely measures in the future.
“All three proposals highlight the excellence of our performance,” emphasizes University President Prof. Oliver Günther, Ph.D. “The outlines impressively document our commitment, existing research excellence, and the potential of the University of Potsdam as a whole. The fact that three powerful consortia have come together in different subject areas shows that we have taken a good step forward on our way to becoming one of the top German universities.”
In this issue, we are looking at what is in and behind these proposals: We talked to the researchers who wrote them. We asked them about their plans in case their proposals are successful and they bring a cluster of excellence to the university. But we also looked at the research that has led to the proposals, has long shaped the university’s profile, and earned it national and international recognition. We present a small selection of projects, methods, and researchers to illustrate why there really is excellent research in these proposals!
By the way, “excellence” is also not the end of the flagpole. After all, the adjective “excellent” even has a comparative and a superlative. With this in mind, I wish you the most excellent pleasure reading this issue!
T3  - Portal Wissen: The research magazine of the University of Potsdam [Englische Ausgabe] - 02/2023 
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-611456
SN  - 2198-9974
IS  - 02/2023
ER  - 
TY  - INPR
A1  - Heimsath, Arjun M.
A1  - Korup, Oliver
T1  - Quantifying rates and processes of landscape evolution
T2  - Earth surface processes and landforms : the journal of the British Geomorphological Research Group
Y1  - 2012
U6  - https://doi.org/10.1002/esp.2251
SN  - 0197-9337
VL  - 37
IS  - 2
SP  - 249
EP  - 251
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Hoffmann, Thomas
A1  - Schlummer, Manuela
A1  - Notebaert, Bastiaan
A1  - Verstraeten, Gert
A1  - Korup, Oliver
T1  - Carbon burial in soil sediments from Holocene agricultural erosion, Central Europe
JF  - Global biogeochemical cycles
N2  - Natural and human-induced erosion supplies high amounts of soil organic carbon (OC) to terrestrial drainage networks. Yet OC fluxes in rivers were considered in global budgets only recently. Modern estimates of annual carbon burial in inland river sediments of 0.6 Gt C, or 22% of C transferred from terrestrial ecosystems to river channels, consider only lakes and reservoirs and disregard any long-term carbon burial in hillslope or floodplain sediments. Here we present the first assessment of sediment-bound OC storage in Central Europe from a synthesis of similar to 1500 Holocene hillslope and floodplain sedimentary archives. We show that sediment storage increases with drainage-basin size due to more extensive floodplains in larger river basins. However, hillslopes retain hitherto unrecognized high amounts of eroded soils at the scale of large river basins such that average agricultural erosion rates during the Holocene would have been at least twice as high as reported previously. This anthropogenic hillslope sediment storage exceeds floodplain storage in drainage basins <10(5) km(2), challenging the notion that floodplains are the dominant sedimentary sinks. In terms of carbon burial, OC concentrations in floodplains exceed those on hillslopes, and net OC accumulation rates in floodplains (0.70.2 g C m(-2)a(-1)) surpass those on hillslopes (0.40.1 g C m(-2)a(-1)) over the last 7500 years. We conclude that carbon burial in floodplains and on hillslopes in Central Europe exceeds terrestrial carbon storage in lakes and reservoirs by at least 2 orders of magnitude and should thus be considered in continental carbon budgets.
KW  - soil organic carbon
KW  - human impact
KW  - soil erosion
KW  - hillslope
KW  - floodplain
KW  - deposition
Y1  - 2013
U6  - https://doi.org/10.1002/gbc.20071
SN  - 0886-6236
SN  - 1944-9224
VL  - 27
IS  - 3
SP  - 828
EP  - 835
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Huggel, Christian
A1  - Clague, John J.
A1  - Korup, Oliver
T1  - Is climate change responsible for changing landslide activity in high mountains?
JF  - Earth surface processes and landforms : the journal of the British Geomorphological Research Group
N2  - Climate change, manifested by an increase in mean, minimum, and maximum temperatures and by more intense rainstorms, is becoming more evident in many regions. An important consequence of these changes may be an increase in landslides in high mountains. More research, however, is necessary to detect changes in landslide magnitude and frequency related to contemporary climate, particularly in alpine regions hosting glaciers, permafrost, and snow. These regions not only are sensitive to changes in both temperature and precipitation, but are also areas in which landslides are ubiquitous even under a stable climate. We analyze a series of catastrophic slope failures that occurred in the mountains of Europe, the Americas, and the Caucasus since the end of the 1990s. We distinguish between rock and ice avalanches, debris flows from de-glaciated areas, and landslides that involve dynamic interactions with glacial and river processes. Analysis of these events indicates several important controls on slope stability in high mountains, including: the non-linear response of firn and ice to warming; three-dimensional warming of subsurface bedrock and its relation to site geology; de-glaciation accompanied by exposure of new sediment; and combined short-term effects of precipitation and temperature. Based on several case studies, we propose that the following mechanisms can significantly alter landslide magnitude and frequency, and thus hazard, under warming conditions: (1) positive feedbacks acting on mass movement processes that after an initial climatic stimulus may evolve independently of climate change; (2) threshold behavior and tipping points in geomorphic systems; (3) storage of sediment and ice involving important lag-time effects.
KW  - climate change
KW  - landslides
KW  - glaciers
KW  - permafrost
Y1  - 2012
U6  - https://doi.org/10.1002/esp.2223
SN  - 0197-9337
VL  - 37
IS  - 1
SP  - 77
EP  - 91
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Korup, Oliver
T1  - Earth's portfolio of extreme sediment transport events
JF  - Earth science reviews : the international geological journal bridging the gap between research articles and textbooks
N2  - Quantitative estimates of sediment flux and the global cycling of sediments from hillslopes to rivers, estuaries, deltas, continental shelves, and deep-sea basins have a long research tradition. In this context, extremely large and commensurately rare sediment transport events have so far eluded a systematic analysis. To start filling this knowledge gap I review some of the highest reported sediment yields in mountain rivers impacted by volcanic eruptions, earthquake- and storm-triggered landslide episodes, and catastrophic dam breaks. Extreme specific yields, defined here as those exceeding the 95th percentile of compiled data, are similar to 10(4) t km(-2) yr(-1) if averaged over 1 yr. These extreme yields vary by eight orders of magnitude, but systematically decay with reference intervals from minutes to millennia such that yields vary by three orders of magnitude for a given reference interval. Sediment delivery from natural dam breaks and pyroclastic eruptions dominate these yields for a given reference interval. Even if averaged over 10(2)-10(3) yr, the contribution of individual disturbances may remain elevated above corresponding catchment denudation rates. I further estimate rates of sediment (re-)mobilisation by individual giant terrestrial and submarine mass movements. Less than 50 postglacial submarine mass movements have involved an equivalent of similar to 10% of the contemporary annual global flux of fluvial sediment to Earth's oceans, while mobilisation rates by individual events rival the decadal-scale sediment discharge from tectonically active orogens such as Taiwan or New Zealand. Sediment flushing associated with catastrophic natural dam breaks is non-stationary and shows a distinct kink at the last glacial-interglacial transition, owing to the drainage of very large late Pleistocene ice-marginal lakes. Besides emphasising the contribution of high-magnitude and low-frequency events to the global sediment cascade, these findings stress the importance of sediment storage for fuelling rather than buffering high sediment transport rates.
KW  - Sediment yield
KW  - Erosion
KW  - Extreme event
Y1  - 2012
U6  - https://doi.org/10.1016/j.earscirev.2012.02.006
SN  - 0012-8252
VL  - 112
IS  - 3-4
SP  - 115
EP  - 125
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - GEN
A1  - Korup, Oliver
T1  - Bayesian geomorphology
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - The rapidly growing amount and diversity of data are confronting us more than ever with the need to make informed predictions under uncertainty. The adverse impacts of climate change and natural hazards also motivate our search for reliable predictions. The range of statistical techniques that geomorphologists use to tackle this challenge has been growing, but rarely involves Bayesian methods. Instead, many geomorphic models rely on estimated averages that largely miss out on the variability of form and process. Yet seemingly fixed estimates of channel heads, sediment rating curves or glacier equilibrium lines, for example, are all prone to uncertainties. Neighbouring scientific disciplines such as physics, hydrology or ecology have readily embraced Bayesian methods to fully capture and better explain such uncertainties, as the necessary computational tools have advanced greatly. The aim of this article is to introduce the Bayesian toolkit to scientists concerned with Earth surface processes and landforms, and to show how geomorphic models might benefit from probabilistic concepts. I briefly review the use of Bayesian reasoning in geomorphology, and outline the corresponding variants of regression and classification in several worked examples.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1348 
KW  - Bayes’ rule
KW  - probability
KW  - uncertainty
KW  - prediction
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-539892
SN  - 1866-8372
IS  - 1
ER  - 
TY  - JOUR
A1  - Korup, Oliver
T1  - Bayesian geomorphology
JF  - Earth surface processes and landforms : the journal of the British Geomorphological Research Group
N2  - The rapidly growing amount and diversity of data are confronting us more than ever with the need to make informed predictions under uncertainty. The adverse impacts of climate change and natural hazards also motivate our search for reliable predictions. The range of statistical techniques that geomorphologists use to tackle this challenge has been growing, but rarely involves Bayesian methods. Instead, many geomorphic models rely on estimated averages that largely miss out on the variability of form and process. Yet seemingly fixed estimates of channel heads, sediment rating curves or glacier equilibrium lines, for example, are all prone to uncertainties. Neighbouring scientific disciplines such as physics, hydrology or ecology have readily embraced Bayesian methods to fully capture and better explain such uncertainties, as the necessary computational tools have advanced greatly. The aim of this article is to introduce the Bayesian toolkit to scientists concerned with Earth surface processes and landforms, and to show how geomorphic models might benefit from probabilistic concepts. I briefly review the use of Bayesian reasoning in geomorphology, and outline the corresponding variants of regression and classification in several worked examples.
KW  - Bayes' rule
KW  - probability
KW  - uncertainty
KW  - prediction
Y1  - 2020
U6  - https://doi.org/10.1002/esp.4995
SN  - 0197-9337
SN  - 1096-9837
VL  - 46
IS  - 1
SP  - 151
EP  - 172
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Korup, Oliver
A1  - Görüm, Tolga
A1  - Hayakawa, Yuichi
T1  - Without power? - Landslide inventories in the face of climate change
JF  - Earth surface processes and landforms : the journal of the British Geomorphological Research Group
N2  - Projected scenarios of climate change involve general predictions about the likely changes to the magnitude and frequency of landslides, particularly as a consequence of altered precipitation and temperature regimes. Whether such landslide response to contemporary or past climate change may be captured in differing scaling statistics of landslide size distributions and the erosion rates derived thereof remains debated. We test this notion with simple Monte Carlo and bootstrap simulations of statistical models commonly used to characterize empirical landslide size distributions. Our results show that significant changes to total volumes contained in such inventories may be masked by statistically indistinguishable scaling parameters, critically depending on, among others, the size of the largest of landslides recorded. Conversely, comparable model parameter values may obscure significant, i.e. more than twofold, changes to landslide occurrence, and thus inferred rates of hillslope denudation and sediment delivery to drainage networks. A time series of some of Earth's largest mass movements reveals clustering near and partly before the last glacial-interglacial transition and a distinct step-over from white noise to temporal clustering around this period. However, elucidating whether this is a distinct signal of first-order climate-change impact on slope stability or simply coincides with a transition from short-term statistical noise to long-term steady-state conditions remains an important research challenge.
KW  - landslide
KW  - climate change
KW  - magnitude & frequency
Y1  - 2012
U6  - https://doi.org/10.1002/esp.2248
SN  - 0197-9337
VL  - 37
IS  - 1
SP  - 92
EP  - 99
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Korup, Oliver
A1  - Hayakawa, Yuichi
A1  - Codilean, Alexandru T.
A1  - Matsushi, Yuki
A1  - Saito, Hitoshi
A1  - Oguchi, Takashi
A1  - Matsuzaki, Hiroyuki
T1  - Japan's sediment flux to the Pacific Ocean revisited
JF  - Earth science reviews : the international geological journal bridging the gap between research articles and textbooks
N2  - Quantifying volumes and rates of delivery of terrestrial sediment from island arcs to subduction zones is indispensable for refining estimates of the thickness of trench fills that may eventually control the location and timing of submarine landslides and tsunami-generating mega-earthquakes. Despite these motivating insights, knowledge about the rates of erosion and sediment export from the Japanese islands to their Pacific subduction zones remains patchy regardless of the increasing availability of highly resolved data on surface deformation, climate, geology, and topography. Traditionally, natural erosion rates across the island arc have been estimated from regression of topographic catchment metrics and reservoir sedimentation rates that were recorded over several years to decades. We review current research in this context, correct for a systematic bias in one of the most widely used predictions, and present new estimates of decadal to millennial-scale erosion rates of Japan's terrestrial inner forearc. We draw on several independent and unprecedented inventories of mass wasting, reservoir sedimentation, and concentrations of cosmogenic Be-10 in river sands. We find that natural Be-10-derived denudation rates of several mm yr(-1) in the Japanese Alps have been sustained over several centuries to millennia, and are, within error, roughly consistent with sediment yields inferred from artificial reservoir sedimentation. Local exceptions may likely result from release of sediment storage or regional landsliding episodes that trigger transient sediment pulses. Our synopsis further reveals that catchments draining Japan's eastern seaboard differ distinctly in their tectonic, lithological, topographic, and climatic characteristics between the Tohoku, Japanese Alps, and Nankai inner forearc segments, which is underscored by a marked asymmetric pattern of erosion rates along the island arc. Erosion rates are highest (up to at least 3 mm yr(-1)) in the Japanese Alps that mark the collision of two subduction zones, where high topographic relief, hillslope and bedrock-channel steepness foster rapid denudation by mass wasting. Comparable, if slightly lower, erosion rates characterise the Nankai inner forearc in southwest Japan, most likely due to higher typhoon-driven rainfall totals and variability rather than its high topographic relief. In contrast, our estimated erosion and flux rates are lowest in the Tohoku inner forearc catchments that feed sediment into the Japan Trench. We conclude that collisional mountain building of the Japanese Alps drives some of the highest erosion rates in the island arc despite similar uplift and precipitation controls in southwest Japan. We infer that, prior to extensive river damming, reservoir construction, and coastal works, the gross of Japan's total sediment export to the Pacific Ocean entered the accretionary margin of the Nankai Trough as opposed to the comparatively sediment-starved Japan Trench. Compared to documented contemporary rates of sediment flux from mountainous catchments elsewhere in the Pacific, the rivers draining Japan's inner forearc take an intermediate position despite high relief, steep slopes, very high seismicity, and frequent rainstorms. However, the average rates of millennial-scale denudation in the Japanese Alps particularly are amongst the highest reported worldwide.

Local mismatches between these late Holocene and modern rates emphasise the anthropogenic fingerprint on sediment retention that may have significantly reduced the island arc's mass flux to its subduction zones, as is the case elsewhere in east and southeast Asia. (C) 2014 Elsevier B.V. All rights reserved.
KW  - Erosion
KW  - Japan
KW  - Subduction zone
KW  - Landslides
KW  - Cosmogenic nuclides
KW  - Sediment budget
Y1  - 2014
U6  - https://doi.org/10.1016/j.earscirev.2014.03.004
SN  - 0012-8252
SN  - 1872-6828
VL  - 135
SP  - 1
EP  - 16
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Korup, Oliver
A1  - Mohr, Christian Heinrich
A1  - Manga, Michael M.
T1  - Bayesian detection of streamflow response to earthquakes
JF  - Water resources research : an AGU journal
N2  - Detecting whether and how river discharge responds to strong earthquake shaking can be time-consuming and prone to operator bias when checking hydrographs from hundreds of gauging stations. We use Bayesian piecewise regression models to show that up to a fifth of all gauging stations across Chile had their largest change in daily streamflow trend on the day of the M-w 8.8 Maule earthquake in 2010. These stations cluster distinctly in the near field though the number of detected streamflow changes varies with model complexity and length of time window considered. Credible seismic streamflow changes at several stations were the highest detectable in eight months, with an increased variance of discharge surpassing the variance of discharge following rainstorms. We conclude that Bayesian piecewise regression sheds new and unbiased insights on the duration, trend, and variance of streamflow response to strong earthquakes, and on how this response compares to that following rainstorms.
KW  - Bayesian analysis
KW  - Chile
KW  - discharge
KW  - earthquake
KW  - streamflow changes
Y1  - 2021
U6  - https://doi.org/10.1029/2020WR028874
SN  - 0043-1397
SN  - 1944-7973
VL  - 57
IS  - 7
PB  - Wiley
CY  - Hoboken, NJ
ER  - 
TY  - JOUR
A1  - Korup, Oliver
A1  - Rixen, C.
T1  - Soil erosion and organic carbon export by wet snow avalanches
JF  - The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union
N2  - Many mountain belts sustain prolonged snow cover for parts of the year, although enquiries into rates of erosion in these landscapes have focused almost exclusively on the snow-free periods. This raises the question of whether annual snow cover contributes significantly to modulating rates of erosion in high-relief terrain. In this context, the sudden release of snow avalanches is a frequent and potentially relevant process, judging from the physical damage to subalpine forest ecosystems, and the amount of debris contained in avalanche deposits. To quantitatively constrain this visual impression and to expand the sparse literature, we sampled sediment concentrations of n = 28 river-spanning snow-avalanche deposits (snow bridges) in the area around Davos, eastern Swiss Alps, and inferred an orders-of-magnitude variability in specific fine sediment and organic carbon yields (1.8 to 830 t km(-2) yr(-1), and 0.04 to 131 tC km(-2) yr(-1), respectively). A Monte Carlo simulation demonstrates that, with a minimum of free parameters, such variability is inherent to the geometric scaling used for computing specific yields. Moreover, the widely applied method of linearly extrapolating plot scale sample data may be prone to substantial under- or overestimates. A comparison of our inferred yields with previously published work demonstrates the relevance of wet snow avalanches as prominent agents of soil erosion and transporters of biogeochemical constituents to mountain rivers. Given that a number of snow bridges persisted below the insulating debris cover well into the summer months, snow-avalanche deposits also contribute to regulating in-channel sediment and organic debris storage on seasonal timescales. Finally, our results underline the potential shortcomings of neglecting erosional processes in the winter and spring months in mountainous terrain subjected to prominent snow cover.
Y1  - 2014
U6  - https://doi.org/10.5194/tc-8-651-2014
SN  - 1994-0416
SN  - 1994-0424
VL  - 8
IS  - 2
SP  - 651
EP  - 658
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Korup, Oliver
A1  - Seidemann, Jan
A1  - Mohr, Christian Heinrich
T1  - Increased landslide activity on forested hillslopes following two recent volcanic eruptions in Chile
JF  - Nature geoscience
N2  - Large explosive eruptions can bury landscapes beneath thick layers of tephra. Rivers subsequently overloaded with excess pyroclastic sediments have some of the highest reported specific sediment yields. Much less is known about how hillslopes respond to tephra loads. Here, we report a pulsed and distinctly delayed increase in landslide activity following the eruptions of the Chaiten (2008) and Puyehue-Cordon Caulle (2011) volcanoes in southern Chile. Remote-sensing data reveal that land-slides clustered in densely forested hillslopes mostly two to six years after being covered by tephra. This lagged instability is consistent with a gradual loss of shear strength of decaying tree roots in areas of high tephra loads. Surrounding areas with comparable topography, forest cover, rainfall and lithology maintained landslide rates roughly ten times lower. The landslides eroded the landscape by up to 4.8 mm on average within 30 km of both volcanoes, mobilizing up to 1.6 MtC at rates of about 265 tC km(-2) yr(-1). We suggest that these yields may reinforce the elevated river loads of sediment and organic carbon in the decade after the eruptions. We recommend that studies of post-eruptive mass fluxes and hazards include lagged landslide responses of tephra-covered forested hillslopes, to avoid substantial underestimates.
Y1  - 2019
U6  - https://doi.org/10.1038/s41561-019-0315-9
SN  - 1752-0894
SN  - 1752-0908
VL  - 12
IS  - 4
SP  - 284
EP  - 289
PB  - Nature Publ. Group
CY  - New York
ER  - 
TY  - JOUR
A1  - Korzeniowska, Karolina
A1  - Buehler, Yves
A1  - Marty, Mauro
A1  - Korup, Oliver
T1  - Regional snow-avalanche detection using object-based image analysis of near-infrared aerial imagery
JF  - Natural hazards and earth system sciences
N2  - Snow avalanches are destructive mass movements in mountain regions that continue to claim lives and cause infrastructural damage and traffic detours. Given that avalanches often occur in remote and poorly accessible steep terrain, their detection and mapping is extensive and time consuming. Nonetheless, systematic avalanche detection over large areas could help to generate more complete and up-to-date inventories (cadastres) necessary for validating avalanche forecasting and hazard mapping. In this study, we focused on automatically detecting avalanches and classifying them into release zones, tracks, and run-out zones based on 0.25m near-infrared (NIR) ADS80-SH92 aerial imagery using an object-based image analysis (OBIA) approach. Our algorithm takes into account the brightness, the normalised difference vegetation index (NDVI), the normalised difference water index (NDWI), and its standard deviation (SDNDWI) to distinguish avalanches from other land-surface elements. Using normalised parameters allows applying this method across large areas. We trained the method by analysing the properties of snow avalanches at three 4km&#8722;2 areas near Davos, Switzerland. We compared the results with manually mapped avalanche polygons and obtained a user's accuracy of >0.9 and a Cohen's kappa of 0.79–0.85. Testing the method for a larger area of 226.3km&#8722;2, we estimated producer's and user's accuracies of 0.61 and 0.78, respectively, with a Cohen's kappa of 0.67. Detected avalanches that overlapped with reference data by >80% occurred randomly throughout the testing area, showing that our method avoids overfitting. Our method has potential for large-scale avalanche mapping, although further investigations into other regions are desirable to verify the robustness of our selected thresholds and the transferability of the method.
Y1  - 2017
U6  - https://doi.org/10.5194/nhess-17-1823-2017
SN  - 1561-8633
VL  - 17
SP  - 1823
EP  - 1836
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Korzeniowska, Karolina
A1  - Bühler, Yves
A1  - Marty, Mauro
A1  - Korup, Oliver
T1  - Regional snow-avalanche detection using object-based image analysis of near-infrared aerial imagery
JF  - Natural hazards and earth system sciences : NHESS
N2  - Snow avalanches are destructive mass movements in mountain regions that continue to claim lives and cause infrastructural damage and traffic detours. Given that avalanches often occur in remote and poorly accessible steep terrain, their detection and mapping is extensive and time consuming. Nonetheless, systematic avalanche detection over large areas could help to generate more complete and up-to-date inventories (cadastres) necessary for validating avalanche forecasting and hazard mapping. In this study, we focused on automatically detecting avalanches and classifying them into release zones, tracks, and run-out zones based on 0.25 m near-infrared (NIR) ADS80-SH92 aerial imagery using an object-based image analysis (OBIA) approach. Our algorithm takes into account the brightness, the normalised difference vegetation index (NDVI), the normalised difference water index (NDWI), and its standard deviation (SDNDWI) to distinguish avalanches from other land-surface elements. Using normalised parameters allows applying this method across large areas. We trained the method by analysing the properties of snow avalanches at three 4 km−2 areas near Davos, Switzerland. We compared the results with manually mapped avalanche polygons and obtained a user's accuracy of > 0.9 and a Cohen's kappa of 0.79–0.85. Testing the method for a larger area of 226.3 km−2, we estimated producer's and user's accuracies of 0.61 and 0.78, respectively, with a Cohen's kappa of 0.67. Detected avalanches that overlapped with reference data by > 80 % occurred randomly throughout the testing area, showing that our method avoids overfitting. Our method has potential for large-scale avalanche mapping, although further investigations into other regions are desirable to verify the robustness of our selected thresholds and the transferability of the method.
Y1  - 2017
U6  - https://doi.org/10.5194/nhess-17-1823-2017
SN  - 1561-8633
VL  - 17
SP  - 1823
EP  - 1836
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - GEN
A1  - Korzeniowska, Karolina
A1  - Bühler, Yves
A1  - Mauro, Marty
A1  - Korup, Oliver
T1  - Regional snow-avalanche detection using object-based image analysis of near-infrared aerial imagery
N2  - Snow avalanches are destructive mass movements in mountain regions that continue to claim lives and cause infrastructural damage and traffic detours. Given that avalanches often occur in remote and poorly accessible steep terrain, their detection and mapping is extensive and time consuming. Nonetheless, systematic avalanche detection over large areas could help to generate more complete and up-to-date inventories (cadastres) necessary for validating avalanche forecasting and hazard mapping. In this study, we focused on automatically detecting avalanches and classifying them into release zones, tracks, and run-out zones based on 0.25 m near-infrared (NIR) ADS80-SH92 aerial imagery using an object-based image analysis (OBIA) approach. Our algorithm takes into account the brightness, the normalised difference vegetation index (NDVI), the normalised difference water index (NDWI), and its standard deviation (SDNDWI) to distinguish avalanches from other land-surface elements. Using normalised parameters allows applying this method across large areas. We trained the method by analysing the properties of snow avalanches at three 4 km−2 areas near Davos, Switzerland. We compared the results with manually mapped avalanche polygons and obtained a user's accuracy of > 0.9 and a Cohen's kappa of 0.79–0.85. Testing the method for a larger area of 226.3 km−2, we estimated producer's and user's accuracies of 0.61 and 0.78, respectively, with a Cohen's kappa of 0.67. Detected avalanches that overlapped with reference data by > 80 % occurred randomly throughout the testing area, showing that our method avoids overfitting. Our method has potential for large-scale avalanche mapping, although further investigations into other regions are desirable to verify the robustness of our selected thresholds and the transferability of the method.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 398 
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-403942
ER  - 
TY  - GEN
A1  - Korzeniowska, Karolina
A1  - Korup, Oliver
T1  - Object-based detection of lakes prone to seasonal ice cover on the Tibetan Plateau
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - The Tibetan Plateau, the world's largest orogenic plateau, hosts thousands of lakes that play prominent roles as water resources, environmental archives, and sources of natural hazards such as glacier lake outburst floods. Previous studies have reported that the size of lakes on the Tibetan Plateau has changed rapidly in recent years, possibly because of atmospheric warming. Tracking these changes systematically with remote sensing data is challenging given the different spectral signatures of water, the potential for confusing lakes with glaciers, and difficulties in classifying frozen or partly frozen lakes. Object-based image analysis (OBIA) offers new opportunities for automated classification in this context, and we have explored this method for mapping lakes from LANDSAT images and Shuttle Radar Topography Mission (SRTM) elevation data. We tested our algorithm for most of the Tibetan Plateau, where lakes in tectonic depressions or blocked by glaciers and sediments have different surface colours and seasonal ice cover in images obtained in 1995 and 2015. We combined a modified normalised difference water index (MNDWI) with OBIA and local topographic slope data in order to classify lakes with an area > 10 km(2). Our method derived 323 water bodies, with a total area of 31,258 km(2), or 2.6% of the study area (in 2015). The same number of lakes had covered only 24,892 km(2) in 1995; lake area has increased by -26% in the past two decades. The classification had estimated producer's and user's accuracies of 0.98, with a Cohen's kappa and F-score of 0.98, and may thus be a useful approximation for quantifying regional hydrological budgets. We have shown that our method is flexible and transferable to detecting lakes in diverse physical settings on several continents with similar success rates.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1037 
KW  - Tibetan Plateau
KW  - lakes
KW  - LANDSAT
KW  - SRTM
KW  - MNDWI
KW  - OBIA
KW  - change detection
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-475037
SN  - 1866-8372
IS  - 1037
ER  - 
TY  - JOUR
A1  - Korzeniowska, Karolina
A1  - Korup, Oliver
T1  - Object-Based Detection of Lakes Prone to Seasonal Ice Cover on the Tibetan Plateau
JF  - Remote sensing
KW  - Tibetan Plateau
KW  - lakes
KW  - LANDSAT
KW  - SRTM
KW  - MNDWI
KW  - OBIA
KW  - change detection
Y1  - 2017
U6  - https://doi.org/10.3390/rs9040339
SN  - 2072-4292
VL  - 9
PB  - MDPI
CY  - Basel
ER  - 
TY  - GEN
A1  - Meyer, Nele Kristin
A1  - Schwanghart, Wolfgang
A1  - Korup, Oliver
A1  - Nadim, F.
T1  - Roads at risk
BT  - traffic detours from debris flows in southern Norway
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Globalisation and interregional exchange of people, goods, and services has boosted the importance of and reliance on all kinds of transport networks. The linear structure of road networks is especially sensitive to natural hazards. In southern Norway, steep topography and extreme weather events promote frequent traffic disruption caused by debris flows. Topographic susceptibility and trigger frequency maps serve as input into a hazard appraisal at the scale of first-order catchments to quantify the impact of debris flows on the road network in terms of a failure likelihood of each link connecting two network vertices, e.g. road junctions. We compute total additional traffic loads as a function of traffic volume and excess distance, i.e. the extra length of an alternative path connecting two previously disrupted network vertices using a shortest-path algorithm. Our risk metric of link failure is the total additional annual traffic load, expressed as vehicle kilometres, because of debris-flow-related road closures. We present two scenarios demonstrating the impact of debris flows on the road network and quantify the associated path-failure likelihood between major cities in southern Norway. The scenarios indicate that major routes crossing the central and north-western part of the study area are associated with high link-failure risk. Yet options for detours on major routes are manifold and incur only little additional costs provided that drivers are sufficiently well informed about road closures. Our risk estimates may be of importance to road network managers and transport companies relying on speedy delivery of services and goods.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 519 
KW  - network vulnerability
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-409586
SN  - 1866-8372
IS  - 519
ER  - 
TY  - JOUR
A1  - Meyer, Nele Kristin
A1  - Schwanghart, Wolfgang
A1  - Korup, Oliver
A1  - Nadim, F.
T1  - Roads at risk
BT  - traffic detours from debris flows in southern Norway
JF  - Natural hazards and earth system sciences
N2  - Globalisation and interregional exchange of people, goods, and services has boosted the importance of and reliance on all kinds of transport networks. The linear structure of road networks is especially sensitive to natural hazards. In southern Norway, steep topography and extreme weather events promote frequent traffic disruption caused by debris flows. Topographic susceptibility and trigger frequency maps serve as input into a hazard appraisal at the scale of first-order catchments to quantify the impact of debris flows on the road network in terms of a failure likelihood of each link connecting two network vertices, e.g. road junctions. We compute total additional traffic loads as a function of traffic volume and excess distance, i.e. the extra length of an alternative path connecting two previously disrupted network vertices using a shortest-path algorithm. Our risk metric of link failure is the total additional annual traffic load, expressed as vehicle kilometres, because of debris-flow-related road closures. We present two scenarios demonstrating the impact of debris flows on the road network and quantify the associated path-failure likelihood between major cities in southern Norway. The scenarios indicate that major routes crossing the central and north-western part of the study area are associated with high link-failure risk. Yet options for detours on major routes are manifold and incur only little additional costs provided that drivers are sufficiently well informed about road closures. Our risk estimates may be of importance to road network managers and transport companies relying on speedy delivery of services and goods.
Y1  - 2015
U6  - https://doi.org/10.5194/nhess-15-985-2015
SN  - 1561-8633
VL  - 15
IS  - 5
SP  - 985
EP  - 995
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Meyer, Nele Kristin
A1  - Schwanghart, Wolfgang
A1  - Korup, Oliver
A1  - Romstad, Bard
A1  - Etzelmuller, Bernd
T1  - Estimating the topographic predictability of debris flows
JF  - Geomorphology : an international journal on pure and applied geomorphology
N2  - The Norwegian traffic network is impacted by about 2000 landslides, avalanches, and debris flows each year that incur high economic losses. Despite the urgent need to mitigate future losses, efforts to locate potential debris flow source areas have been rare at the regional scale. We tackle this research gap by exploring a minimal set of possible topographic predictors of debris flow initiation that we input to a Weights-of-Evidence (WofE) model for mapping the regional susceptibility to debris flows in western Norway. We use an inventory of 429 debris flows that were recorded between 1979 and 2008, and use the terrain variables of slope, total curvature, and contributing area (flow accumulation) to compute the posterior probabilities of local debris flow occurrence. The novelty of our approach is that we quantify the uncertainties in the WofE approach arising from different predictor classification schemes and data input, while estimating model accuracy and predictive performance from independent test data. Our results show that a percentile-based classification scheme excels over a manual classification of the predictor variables because differing abundances in manually defined bins reduce the reliability of the conditional independence tests, a key, and often neglected, prerequisite for the WofE method. The conditional dependence between total curvature and flow accumulation precludes their joint use in the model. Slope gradient has the highest true positive rate (88%), although the fraction of area classified as susceptible is very large (37%). The predictive performance, i.e. the reduction of false positives, is improved when combined with either total curvature or flow accumulation. Bootstrapping shows that the combination of slope and flow accumulation provides more reliable predictions than the combination of slope and total curvature, and helps refining the use of slope-area plots for identifying morphometric fingerprints of debris flow source areas, an approach used outside the field of landslide susceptibility assessments.
KW  - Weights-of-Evidence
KW  - Debris flows
KW  - Susceptibility
KW  - Slope-area plot
KW  - Process domains
KW  - Norway
Y1  - 2014
U6  - https://doi.org/10.1016/j.geomorph.2013.10.030
SN  - 0169-555X
SN  - 1872-695X
VL  - 207
SP  - 114
EP  - 125
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Mohr, Christian Heinrich
A1  - Korup, Oliver
A1  - Ulloa, Hector
A1  - Iroume, Andres
T1  - Pyroclastic Eruption Boosts Organic Carbon Fluxes Into Patagonian Fjords
JF  - Global biogeochemical cycles
N2  - Fjords and old-growth forests store large amounts of organic carbon. Yet the role of episodic disturbances, particularly volcanic eruptions, in mobilizing organic carbon in fjord landscapes covered by temperate rainforests remains poorly quantified. To this end, we estimated how much wood and soils were flushed to nearby fjords following the 2008 eruption of Chaiten volcano in south-central Chile, where pyroclastic sediments covered >12km(2) of pristine temperate rainforest. Field-based surveys of forest biomass, soil organic content, and dead wood transport reveal that the reworking of pyroclastic sediments delivered similar to 66,500+14,600/-14,500tC of large wood to two rivers entering the nearby Patagonian fjords in less than a decade. A similar volume of wood remains in dead tree stands and buried beneath pyroclastic deposits (similar to 79,900+21,100/-16,900tC) or stored in active river channels (5,900-10,600tC). We estimate that bank erosion mobilized similar to 132,300(+21,700)/(-30,600)tC of floodplain forest soil. Eroded and reworked forest soils have been accreting on coastal river deltas at >5mmyr(-1) since the eruption. While much of the large wood is transported out of the fjord by long-shore drift, the finer fraction from eroded forest soils is likely to be buried in the fjords. We conclude that the organic carbon fluxes boosted by rivers adjusting to high pyroclastic sediment loads may remain elevated for up to a decade and that Patagonian temperate rainforests disturbed by excessive loads of pyroclastic debris can be episodic short-lived carbon sources. Plain Language Summary Fjords and old-growth forests are important sinks of organic carbon. However, the role of volcanic eruptions in flushing organic carbon in fjord landscapes remains unexplored. Here we estimated how much forest vegetation and soils were lost to fjords following the 2008 eruption ofunknownChaiten volcano in south-central Chile. Pyroclastic sediments obliterated near-pristine temperateunknownrainforest, and the subsequent reworking of these sediments delivered in less than a decade similar to 66,000 tC of large wood to the mountain rivers, draining into the nearby Patagonian fjords. A similar volume of wood remains in dead tree stands and buried beneath pyroclastic deposits or stored in active riverunknownchannels. We estimate that similar to 130,000 tC of organic carbon-rich soil was lost to erosion, thus adding to the carbon loads. While much of the wood enters the long-shore drift in the fjord heads, the finerunknownfraction from eroded forest soils is likely to be buried in the fjords at rates that exceed regional estimates by an order of magnitude. We anticipate that these eruption-driven fluxes will remain elevated forunknownthe coming years and that Patagonian temperate rainforests episodically switch from carbon sinks to hitherto undocumented carbon sources if disturbed by explosive volcanic eruptions.
KW  - Chile
KW  - Patagonia
KW  - rainforest
KW  - volcanic eruption
KW  - organic carbon
KW  - biomass
Y1  - 2017
U6  - https://doi.org/10.1002/2017GB005647
SN  - 0886-6236
SN  - 1944-9224
VL  - 31
SP  - 1626
EP  - 1638
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Mohr, Christian Heinrich
A1  - Manga, Michael
A1  - Wang, Chi-Yuen
A1  - Korup, Oliver
T1  - Regional changes in streamflow after a megathrust earthquake
JF  - Earth & planetary science letters
N2  - Moderate to large earthquakes can increase the amount of water feeding stream flows, mobilizing excess water from deep groundwater, shallow groundwater, or the vadose zone. Here we examine the regional pattern of streamflow response to the Maule M8.8 earthquake across Chile's diverse topographic and hydro-climatic gradients. We combine streamflow analyses with groundwater flow modeling and a random forest classifier, and find that, after the earthquake, at least 85 streams had a change in flow. Discharge mostly increased () shortly after the earthquake, liberating an excess water volume of >1.1 km3, which is the largest ever reported following an earthquake. Several catchments had increased discharge of >50 mm, locally exceeding seasonal streamflow discharge under undisturbed conditions. Our modeling results favor enhanced vertical permeability induced by dynamic strain as the most probable process explaining the observed changes at the regional scale. Supporting this interpretation, our random forest classification identifies peak ground velocity and elevation extremes as most important for predicting streamflow response. Given the mean recurrence interval of ∼25 yr for >M8.0 earthquakes along the Peru–Chile Trench, our observations highlight the role of earthquakes in the regional water cycle, especially in arid environments.
KW  - Maule earthquake
KW  - streamflow response
KW  - permeability
KW  - groundwater flow modeling
KW  - earthquake hydrology
Y1  - 2016
U6  - https://doi.org/10.1016/j.epsl.2016.11.013
SN  - 0012-821X
SN  - 1385-013X
VL  - 458
SP  - 418
EP  - 428
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Mohr, Christian Heinrich
A1  - Zimmermann, Andreas
A1  - Korup, Oliver
A1  - Iroume, A.
A1  - Francke, Till
A1  - Bronstert, Axel
T1  - Seasonal logging, process response, and geomorphic work
JF  - Earth surface dynamics
N2  - Deforestation is a prominent anthropogenic cause of erosive overland flow and slope instability, boosting rates of soil erosion and concomitant sediment flux. Conventional methods of gauging or estimating post-logging sediment flux often focus on annual timescales but overlook potentially important process response on shorter intervals immediately following timber harvest. We resolve such dynamics with non-parametric quantile regression forests (QRF) based on high-frequency (3 min) discharge measurements and sediment concentration data sampled every 30-60 min in similar-sized (similar to 0.1 km(2)) forested Chilean catchments that were logged during either the rainy or the dry season. The method of QRF builds on the random forest algorithm, and combines quantile regression with repeated random sub-sampling of both cases and predictors. The algorithm belongs to the family of decision-tree classifiers, which allow quantifying relevant predictors in high-dimensional parameter space. We find that, where no logging occurred, similar to 80% of the total sediment load was transported during extremely variable runoff events during only 5% of the monitoring period. In particular, dry-season logging dampened the relative role of these rare, extreme sediment-transport events by increasing load efficiency during more efficient moderate events. We show that QRFs outperform traditional sediment rating curves (SRCs) in terms of accurately simulating short-term dynamics of sediment flux, and conclude that QRF may reliably support forest management recommendations by providing robust simulations of post-logging response of water and sediment fluxes at high temporal resolution.
Y1  - 2014
U6  - https://doi.org/10.5194/esurf-2-117-2014
SN  - 2196-6311
SN  - 2196-632X
VL  - 2
IS  - 1
SP  - 117
EP  - 125
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Munack, Henry
A1  - Blöthe, Jan Henrik
A1  - Fülöp, R. H.
A1  - Codilean, Alexandru T.
A1  - Fink, D.
A1  - Korup, Oliver
T1  - Recycling of Pleistocene valley fills dominates 135 ka of sediment flux, upper Indus River
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
KW  - Transhimalaya
KW  - Zanskar
KW  - Indus
KW  - Valley fill
KW  - Drainage capture
KW  - In-situ cosmogenic Be-10
Y1  - 2016
U6  - https://doi.org/10.1016/j.quascirev.2016.07.030
SN  - 0277-3791
VL  - 149
SP  - 122
EP  - 134
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Munack, Henry
A1  - Korup, Oliver
A1  - Resentini, Alberto
A1  - Limonta, Mara
A1  - Garzanti, Eduardo
A1  - Bloethe, Jan H.
A1  - Scherler, Dirk
A1  - Wittmann, Hella
A1  - Kubik, Peter W.
T1  - Postglacial denudation of western Tibetan Plateau margin outpaced by long-term exhumation
JF  - Geological Society of America bulletin
N2  - The Indus River, one of Asia's premier rivers, drains the western Tibetan Plateau and the Nanga Parbat syntaxis. These two areas juxtapose some of the lowest and highest topographic relief and commensurate denudation rates in the Himalaya-Tibet orogen, respectively, yet the spatial pattern of denudation rates upstream of the syntaxis remains largely unclear, as does the way in which major rivers drive headward incision into the Tibetan Plateau. We report a new inventory of Be-10-based basinwide denudation rates from 33 tributaries flanking the Indus River along a 320 km reach across the western Tibetan Plateau margin. We find that denudation rates of up to 110 mm k.y.(-1) in the Ladakh and Zanskar Ranges systematically decrease eastward to 10 mm k.y.(-1) toward the Tibetan Plateau. Independent results from bulk petrographic and heavy mineral analyses support this denudation gradient. Assuming that incision along the Indus exerts the base-level control on tributary denudation rates, our data show a systematic eastward decrease of landscape downwearing, reaching its minimum on the Tibetan Plateau. In contrast, denudation rates increase rapidly 150-200 km downstream of a distinct knick-point that marks the Tibetan Plateau margin in the Indus River longitudinal profile. We infer that any vigorous headward incision and any accompanying erosional waves into the interior of the plateau mostly concerned reaches well below this plateau margin. Moreover, reported long-term (>10(6) yr) exhumation rates from low-temperature chronometry of 0.1-0.75 mm yr(-1) consistently exceed our Be-10-derived denudation rates. With averaging time scales of 10(3)-10(4) yr for our denudation data, we report postglacial rates of downwearing in a tectonically idle landscape. To counterbalance this apparent mismatch, denudation rates must have been higher in the Quaternary during glacial-interglacial intervals.
Y1  - 2014
U6  - https://doi.org/10.1130/B30979.1
SN  - 0016-7606
SN  - 1943-2674
VL  - 126
IS  - 11-12
SP  - 1580
EP  - 1594
PB  - American Institute of Physics
CY  - Boulder
ER  - 
TY  - JOUR
A1  - Ozturk, Ugur
A1  - Marwan, Norbert
A1  - Korup, Oliver
A1  - Saito, H.
A1  - Agarwa, Ankit
A1  - Grossman, M. J.
A1  - Zaiki, M.
A1  - Kurths, Jürgen
T1  - Complex networks for tracking extreme rainfall during typhoons
JF  - Chaos : an interdisciplinary journal of nonlinear science
N2  - Reconciling the paths of extreme rainfall with those of typhoons remains difficult despite advanced forecasting techniques. We use complex networks defined by a nonlinear synchronization measure termed event synchronization to track extreme rainfall over the Japanese islands. Directed networks objectively record patterns of heavy rain brought by frontal storms and typhoons but mask out contributions of local convective storms. We propose a radial rank method to show that paths of extreme rainfall in the typhoon season (August-November, ASON) follow the overall southwest-northeast motion of typhoons and mean rainfall gradient of Japan. The associated eye-of-the-typhoon tracks deviate notably and may thus distort estimates of heavy typhoon rainfall. We mainly found that the lower spread of rainfall tracks in ASON may enable better hindcasting than for westerly-fed frontal storms in June and July.
Y1  - 2018
U6  - https://doi.org/10.1063/1.5004480
SN  - 1054-1500
SN  - 1089-7682
VL  - 28
IS  - 7
PB  - American Institute of Physics
CY  - Melville
ER  - 
TY  - JOUR
A1  - Ozturk, Ugur
A1  - Pittore, Massimiliano
A1  - Behling, Robert
A1  - Rößner, Sigrid
A1  - Andreani, Louis
A1  - Korup, Oliver
T1  - How robust are landslide susceptibility estimates?
JF  - Landslides
N2  - Much of contemporary landslide research is concerned with predicting and mapping susceptibility to slope failure. Many studies rely on generalised linear models with environmental predictors that are trained with data collected from within and outside of the margins of mapped landslides. Whether and how the performance of these models depends on sample size, location, or time remains largely untested. We address this question by exploring the sensitivity of a multivariate logistic regression-one of the most widely used susceptibility models-to data sampled from different portions of landslides in two independent inventories (i.e. a historic and a multi-temporal) covering parts of the eastern rim of the Fergana Basin, Kyrgyzstan. We find that considering only areas on lower parts of landslides, and hence most likely their deposits, can improve the model performance by >10% over the reference case that uses the entire landslide areas, especially for landslides of intermediate size. Hence, using landslide toe areas may suffice for this particular model and come in useful where landslide scars are vague or hidden in this part of Central Asia. The model performance marginally varied after progressively updating and adding more landslides data through time. We conclude that landslide susceptibility estimates for the study area remain largely insensitive to changes in data over about a decade. Spatial or temporal stratified sampling contributes only minor variations to model performance. Our findings call for more extensive testing of the concept of dynamic susceptibility and its interpretation in data-driven models, especially within the broader framework of landslide risk assessment under environmental and land-use change.
KW  - Landslide susceptibility
KW  - Logistic regression
KW  - Southern Kyrgyzstan
KW  - Landslide inventory
KW  - Remote sensing
Y1  - 2020
U6  - https://doi.org/10.1007/s10346-020-01485-5
SN  - 1612-510X
SN  - 1612-5118
VL  - 18
IS  - 2
SP  - 681
EP  - 695
PB  - Springer
CY  - Heidelberg
ER  - 
TY  - GEN
A1  - Ozturk, Ugur
A1  - Pittore, Massimiliano
A1  - Behling, Robert
A1  - Rößner, Sigrid
A1  - Andreani, Louis
A1  - Korup, Oliver
T1  - How robust are landslide susceptibility estimates?
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Much of contemporary landslide research is concerned with predicting and mapping susceptibility to slope failure. Many studies rely on generalised linear models with environmental predictors that are trained with data collected from within and outside of the margins of mapped landslides. Whether and how the performance of these models depends on sample size, location, or time remains largely untested. We address this question by exploring the sensitivity of a multivariate logistic regression-one of the most widely used susceptibility models-to data sampled from different portions of landslides in two independent inventories (i.e. a historic and a multi-temporal) covering parts of the eastern rim of the Fergana Basin, Kyrgyzstan. We find that considering only areas on lower parts of landslides, and hence most likely their deposits, can improve the model performance by >10% over the reference case that uses the entire landslide areas, especially for landslides of intermediate size. Hence, using landslide toe areas may suffice for this particular model and come in useful where landslide scars are vague or hidden in this part of Central Asia. The model performance marginally varied after progressively updating and adding more landslides data through time. We conclude that landslide susceptibility estimates for the study area remain largely insensitive to changes in data over about a decade. Spatial or temporal stratified sampling contributes only minor variations to model performance. Our findings call for more extensive testing of the concept of dynamic susceptibility and its interpretation in data-driven models, especially within the broader framework of landslide risk assessment under environmental and land-use change.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1346 
KW  - Landslide susceptibility
KW  - logistic regression
KW  - Southern Kyrgyzstan
KW  - Landslide inventory
KW  - remote sensing
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-541980
SN  - 1866-8372
IS  - 2
ER  - 
TY  - JOUR
A1  - Ozturk, Ugur
A1  - Wendi, Dadiyorto
A1  - Crisologo, Irene
A1  - Riemer, Adrian
A1  - Agarwal, Ankit
A1  - Vogel, Kristin
A1  - Andres Lopez-Tarazon, Jose
A1  - Korup, Oliver
T1  - Rare flash floods and debris flows in southern Germany
JF  - The science of the total environment : an international journal for scientific research into the environment and its relationship with man
N2  - Flash floods and debris flows are iconic hazards inmountainous regions with steep relief, high rainfall intensities, rapid snowmelt events, and abundant sediments. The cuesta landscapes of southern Germany hardly come to mind when dealing with such hazards. A series of heavy rainstorms dumping up to 140mm in 2 h caused destructive flash floods and debris flows in May 2016. The most severe damage occurred in the Braunsbach municipality, which was partly buried by 42,000 m(3) of boulders, gravel, mud, and anthropogenic debris from the small catchment of Orlacher Bach (similar to 6 km(2)). We analysed this event by combining rainfall patterns, geological conditions, and geomorphic impacts to estimate an average sediment yield of 14,000 t/km(2) that mostly (similar to 95%) came from some 50 riparian landslides and channel-bed incision of similar to 2 m. This specific sediment yield ranks among the top 20% globally, while the intensity-duration curve of the rainstormis similarly in the upper percentile range of storms that had triggered landslides. Compared to similar-sized catchments in the greater region hit by the rainstorms, we find that the Orlacher Bach is above the 95th percentile in terms of steepness, storm-rainfall intensity, and topographic curvatures. The flash flood transported a sediment volume equal to as much as 20-40% of the Pleistocene sediment volume stored in the Orlacher Bach fan, andmay have had several predecessors in the Holocene. River control structures from 1903 and records of a debris flow in the 1920s in a nearby catchment indicate that the local inhabitants may have been aware of the debris-flow hazards earlier. Such recurring and destructive events elude flood-hazard appraisals in humid landscapes of gentle relief, and broaden mechanistic views of how landslides and debris flows contribute to shaping small and deeply cut tributaries in the southern Germany cuesta landscape.
KW  - Flash flood
KW  - Debris flow
KW  - Rainfall-triggered landslide
KW  - Hazard
KW  - Germany
Y1  - 2018
U6  - https://doi.org/10.1016/j.scitotenv.2018.01.172
SN  - 0048-9697
SN  - 1879-1026
VL  - 626
SP  - 941
EP  - 952
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Panek, Tomas
A1  - Korup, Oliver
A1  - Lenart, Jan
A1  - Hradecky, Jan
A1  - Brezny, Michal
T1  - Giant landslides in the foreland of the Patagonian Ice Sheet
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
N2  - Quaternary glaciations have repeatedly shaped large tracts of the Andean foreland. Its spectacular large glacial lakes, staircases of moraine ridges, and extensive outwash plains have inspired generations of scientists to reconstruct the processes, magnitude, and timing of ice build-up and decay at the mountain front. Surprisingly few of these studies noticed many dozens of giant (≥108 m3) mass-wasting deposits in the foreland. We report some of the world's largest terrestrial landslides in the eastern piedmont of the Patagonian Ice Sheet (PIS) along the traces of the former Lago Buenos Aires and Lago Puyerredón glacier lobes and lakes. More than 283 large rotational slides and lateral spreads followed by debris slides, earthflows, rotational and translational rockslides, complex slides and few large rock avalanches detached some 164 ± 56 km3 of material from the slopes of volcanic mesetas, lake-bounding moraines, and river-gorge walls. Many of these landslide deposits intersect with well-dated moraine ridges or former glacial-lake shorelines, and offer opportunities for relative dating of slope failure. We estimate that >60% of the landslide volume (∼96 km3) detached after the Last Glacial Maximum (LGM). Giant slope failures cross-cutting shorelines of a large Late Glacial to Early Holocene lake (“glacial lake PIS”) likely occurred during successive lake-level drop between ∼11.5 and 8 ka, and some of them are the largest hitherto documented landslides in moraines. We conclude that 1) large portions of terminal moraines can fail catastrophically several thousand years after emplacement; 2) slopes formed by weak bedrock or unconsolidated glacial deposits bordering glacial lakes can release extremely large landslides; and 3) landslides still occur in the piedmont, particularly along postglacial gorges cut in response to falling lake levels.
KW  - Quaternary
KW  - Landslide
KW  - Geomorphology
KW  - Relative dating
KW  - Glacier foreland
KW  - Glacial lake
KW  - Patagonian Ice Sheet
KW  - Paleogeography
KW  - South America
Y1  - 2018
U6  - https://doi.org/10.1016/j.quascirev.2018.06.028
SN  - 0277-3791
VL  - 194
SP  - 39
EP  - 54
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Panek, Tomas
A1  - Korup, Oliver
A1  - Minar, Jozef
A1  - Hradecky, Jan
T1  - Giant landslides and highstands of the Caspian Sea
JF  - Geology
Y1  - 2016
U6  - https://doi.org/10.1130/G38259.1
SN  - 0091-7613
SN  - 1943-2682
VL  - 44
SP  - 939
EP  - 942
PB  - American Institute of Physics
CY  - Boulder
ER  - 
TY  - JOUR
A1  - Parra Hormazábal, Eric
A1  - Mohr, Christian Heinrich
A1  - Korup, Oliver
T1  - Predicting Patagonian landslides
BT  - roles of forest cover and wind speed
JF  - Geophysical research letters : GRL / American Geophysical Union
N2  - Dense tree stands and high wind speeds characterize the temperate rainforests of southern Chilean Patagonia, where landslides frequently strip hillslopes of soils, rock, and biomass. Assuming that wind loads on trees promote slope instability, we explore the role of forest cover and wind speed in predicting landslides with a hierarchical Bayesian logistic regression. We find that higher crown openness and wind speeds credibly predict higher probabilities of detecting landslides regardless of topographic location, though much better in low-order channels and on midslope locations than on open slopes. Wind speed has less predictive power in areas that were impacted by tephra fall from recent volcanic eruptions, while the influence of forest cover in terms of crown openness remains. <br /> Plain Language Summary Chilean Patagonia hosts some of Earth's largest swaths of temperate rainforests, where frequent landslides erode soil, rock, and vegetation. We explore the role of forest cover and wind disturbances in promoting such landslides with a model that predicts from crown openness and wind speed the probability of detecting landslide terrain. We find that both forest cover and wind speed play important, yet previously underappreciated, roles in this context, especially when grouped by landform types and previous volcanic disturbance, which may override the comparable modest control of wind on landslides. Our study is the first of its kind in one of the windiest spots on Earth and encourages a more discerning approach to landslide prediction.
Y1  - 2021
U6  - https://doi.org/10.1029/2021GL095224
SN  - 0094-8276
SN  - 1944-8007
VL  - 48
IS  - 23
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Patyniak, Magda
A1  - Landgraf, Angela
A1  - Dzhumabaeva, Atyrgul
A1  - Abdrakhmatov, Kanatbek E.
A1  - Rosenwinkel, Swenja
A1  - Korup, Oliver
A1  - Preusser, Frank
A1  - Fohlmeister, Jens Bernd
A1  - Arrowsmith, J. Ramon
A1  - Strecker, Manfred
T1  - Paleoseismic Record of Three Holocene Earthquakes Rupturing the Issyk-Ata Fault near Bishkek, North Kyrgyzstan
JF  - Bulletin of the Seismological Society of America
N2  - The northern edge of the western central Tien Shan range is bounded by the Issyk-Ata fault situated south of Bishkek, the capital of Kyrgyzstan. Contraction in this thick-skinned orogen occurs with low-strain accumulation and long earthquake recurrence intervals. In the nineteenth to twentieth centuries, a sequence of large earthquakes with magnitudes between 6.9 and 8 affected the northern Tien Shan but left nearly the entire extent of the Issyk-Ata fault unruptured. Here, the only known historic earthquake ruptured in A.D. 1885 (M6.9) along the western end of the Issyk-Ata fault. Because earthquakes in low-strain regions often tend to cluster in time and may promote failure along nearby structures, the earthquake history of the northern Tien Shan represents an exceptional structural setting for studying fault behavior affected by an intraplate earthquake sequence. We present a paleoseismological study from one site (Belek) along the Issyk-Ata fault located east of the A.D. 1885 epicentral area. Our analysis combines a range of tools, including photogrammetry, differential Global Positioning System, 3D visualization, and age modeling with different dating methods (infrared stimulated luminescence, radiocarbon, U-series) to improve the reliability of an event chronology for the trench stratigraphy and fault geometry. We were able to distinguish three different surfacerupturing paleoearthquakes; these affected the area before 10.5 +/- 1.1 cal ka B.P., at similar to 5.6 +/- 1.0 cal ka B.P., and at similar to 630 +/- 100 cal B.P., respectively. Associated paleomagnitudes for the last two earthquakes range between M6.7 and 7.4, with a cumulative slip rate of 0.7 +/- 0.32 mm/yr. We did not find evidence for the A.D. 1885 event at Belek. Our study yielded two main overall results: first, it extends the regional historic and paleoseismic record; second, the documented rupture events along the Issyk-Ata fault suggest that this fault was not affected in its entirety; instead, these events indicate segmented rupture behavior.
Y1  - 2017
U6  - https://doi.org/10.1785/0120170083
SN  - 0037-1106
SN  - 1943-3573
VL  - 107
SP  - 2721
EP  - 2737
PB  - Seismological Society of America
CY  - Albany
ER  - 
TY  - JOUR
A1  - Philips, Andrea
A1  - Walz, Ariane
A1  - Bergner, Andreas G. N.
A1  - Gräff, Thomas
A1  - Heistermann, Maik
A1  - Kienzler, Sarah
A1  - Korup, Oliver
A1  - Lipp, Torsten
A1  - Schwanghart, Wolfgang
A1  - Zeilinger, Gerold
T1  - Immersive 3D geovisualization in higher education
JF  - Journal of geography in higher education
N2  - In this study, we investigate how immersive 3D geovisualization can be used in higher education. Based on MacEachren and Kraak's geovisualization cube, we examine the usage of immersive 3D geovisualization and its usefulness in a research-based learning module on flood risk, called GEOSimulator. Results of a survey among participating students reveal benefits, such as better orientation in the study area, higher interactivity with the data, improved discourse among students and enhanced motivation through immersive 3D geovisualization. This suggests that immersive 3D visualization can effectively be used in higher education and that 3D CAVE settings enhance interactive learning between students.
KW  - immersive 3D geovisualization
KW  - 3D CAVE
KW  - higher education
KW  - learning success
KW  - student survey
KW  - flood risk
Y1  - 2015
U6  - https://doi.org/10.1080/03098265.2015.1066314
SN  - 0309-8265
SN  - 1466-1845
VL  - 39
IS  - 3
SP  - 437
EP  - 449
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
ER  - 
TY  - JOUR
A1  - Rosenwinkel, Swenja
A1  - Korup, Oliver
A1  - Landgraf, Angela
A1  - Dzhumabaeva, Atyrgul
T1  - Limits to lichenometry
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
N2  - Lichenometry is a straightforward and inexpensive method for dating Holocene rock surfaces. The rationale is that the diameter of the largest lichen scales with the age of the originally fresh rock surface that it colonised. The success of the method depends on finding the largest lichen diameters, a suitable lichen-growth model, and a robust calibration curve. Recent critique of the method motivates us to revisit the accuracy and uncertainties of lichenometry. Specifically, we test how well lichenometry is capable of resolving the ages of different lobes of large active rock glaciers in the Kyrgyz Tien Shan. We use a bootstrapped quantile regression to calibrate local growth curves of Xanthoria elegans, Aspicilia tianshanica, and Rhizocarpon geographicum, and report a nonlinear decrease in dating accuracy with increasing lichen diameter. A Bayesian type of an analysis of variance demonstrates that our calibration allows discriminating credibly between rock-glacier lobes of different ages despite the uncertainties tied to sample size and correctly identifying the largest lichen thalli. Our results also show that calibration error grows with lichen size, so that the separability of rock-glacier lobes of different ages decreases, while the tendency to assign coeval ages increases. The abundant young (<200 yr) specimen of fast-growing X elegans are in contrast with the fewer, slow-growing, but older (200-1500 yr) R. geographicum and A. tianshanica, and record either a regional reactivation of lobes in the past 200 years, or simply a censoring effect of lichen mortality during early phases of colonisation. The high variance of lichen sizes captures the activity of rock-glacier lobes, which is difficult to explain by regional climatic cooling or earthquake triggers alone. Therefore, we caution against inferring palaeoclimatic conditions from the topographic position of rock-glacier lobes. We conclude that lichenometry works better as a tool for establishing a relative, rather than an absolute, chronology of rock-glacier lobes in the northern Tien Shan. (C) 2015 Elsevier Ltd. All rights reserved.
KW  - Lichenometry
KW  - Rock glacier
KW  - Absolute age dating
KW  - Kyrgyzstan
KW  - Tien Shan
Y1  - 2015
U6  - https://doi.org/10.1016/j.quascirev.2015.10.031
SN  - 0277-3791
VL  - 129
SP  - 229
EP  - 238
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Rosenwinkel, Swenja
A1  - Landgraf, Angela
A1  - Schwanghart, Wolfgang
A1  - Volkmer, Friedrich
A1  - Dzhumabaeva, Atyrgul
A1  - Merchel, Silke
A1  - Rugel, Georg
A1  - Preusser, Frank
A1  - Korup, Oliver
T1  - Late Pleistocene outburst floods from Issyk Kul, Kyrgyzstan?
JF  - Earth surface processes and landforms : the journal of the British Geomorphological Research Group
KW  - outburst flood
KW  - lake-level changes
KW  - Issyk Kul
KW  - Kyrgyzstan
KW  - cosmogenic nuclides
Y1  - 2017
U6  - https://doi.org/10.1002/esp.4109
SN  - 0197-9337
SN  - 1096-9837
VL  - 42
SP  - 1535
EP  - 1548
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Saito, H.
A1  - Korup, Oliver
A1  - Uchida, T.
A1  - Hayashi, S.
A1  - Oguchi, T.
T1  - Rainfall conditions, typhoon frequency, and contemporary landslide erosion in Japan
JF  - Geology
N2  - Dealing with predicted increases in extreme weather conditions due to climate change requires robust knowledge about controls on rainfall-triggered landslides. We explore relationships between rainfall and landslide size throughout the Japanese archipelago. We test whether the total volume of landslides can be predicted directly from rainfall totals, intensity, and duration using a nationwide inventory of 4744 rainfall-triggered landslides recorded from A.D. 2001 to 2011. We find that larger landslides were more abundant at the expense of smaller ones when total, maximum, and mean rainfall intensity exceeded similar to 250 mm, similar to 35 mm/h, and similar to 4 mm/h, respectively. Frequency distributions of these rainfall parameters are peaked and heavily skewed. Yet neither the most frequent nor the most extreme values of these rainfall metrics coincide consistently with the maximum landslide volumes. A striking decrease of landslide volumes at both mean and maximum rainfall intensity, as well as duration, points to an exhaustion in hillslope geomorphic response regardless of sample size, landslide type, mobilized volume, dominant lithology, or reporting bias. Our results underscore substantial offsets between the peaks of rainfall metrics and maximum associated landslide volumes, thus complicating straightforward estimates of geomorphic work from metrics of rainstorm magnitude or frequency. Only the rainfall total appears to be a suitable monotonic predictor of landslide volumes mobilized during typhoons and frontal storms.
Y1  - 2014
U6  - https://doi.org/10.1130/G35680.1
SN  - 0091-7613
SN  - 1943-2682
VL  - 42
IS  - 11
SP  - 999
EP  - 1002
PB  - American Institute of Physics
CY  - Boulder
ER  - 
TY  - JOUR
A1  - Samprogna Mohor, Guilherme
A1  - Thieken, Annegret
A1  - Korup, Oliver
T1  - Residential flood loss estimated from Bayesian multilevel models
JF  - Natural Hazards and Earth System Sciences
N2  - Models for the predictions of monetary losses from floods mainly blend data deemed to represent a single flood type and region. Moreover, these approaches largely ignore indicators of preparedness and how predictors may vary between regions and events, challenging the transferability of flood loss models. We use a flood loss database of 1812 German flood-affected households to explore how Bayesian multilevel models can estimate normalised flood damage stratified by event, region, or flood process type. Multilevel models acknowledge natural groups in the data and allow each group to learn from others. We obtain posterior estimates that differ between flood types, with credibly varying influences of water depth, contamination, duration, implementation of property-level precautionary measures, insurance, and previous flood experience; these influences overlap across most events or regions, however. We infer that the underlying damaging processes of distinct flood types deserve further attention. Each reported flood loss and affected region involved mixed flood types, likely explaining the uncertainty in the coefficients. Our results emphasise the need to consider flood types as an important step towards applying flood loss models elsewhere. We argue that failing to do so may unduly generalise the model and systematically bias loss estimations from empirical data.
KW  - damage
KW  - insurance
KW  - Germany
KW  - transferability
KW  - preparedness
KW  - recovery
Y1  - 2020
U6  - https://doi.org/10.5194/nhess-21-1599-2021
SN  - 2195-9269
VL  - 21
SP  - 1599
EP  - 1614
PB  - European Geophysical Society
CY  - Katlenburg-Lindau
ER  - 
TY  - GEN
A1  - Samprogna Mohor, Guilherme
A1  - Thieken, Annegret
A1  - Korup, Oliver
T1  - Residential flood loss estimated from Bayesian multilevel models
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Models for the predictions of monetary losses from floods mainly blend data deemed to represent a single flood type and region. Moreover, these approaches largely ignore indicators of preparedness and how predictors may vary between regions and events, challenging the transferability of flood loss models. We use a flood loss database of 1812 German flood-affected households to explore how Bayesian multilevel models can estimate normalised flood damage stratified by event, region, or flood process type. Multilevel models acknowledge natural groups in the data and allow each group to learn from others. We obtain posterior estimates that differ between flood types, with credibly varying influences of water depth, contamination, duration, implementation of property-level precautionary measures, insurance, and previous flood experience; these influences overlap across most events or regions, however. We infer that the underlying damaging processes of distinct flood types deserve further attention. Each reported flood loss and affected region involved mixed flood types, likely explaining the uncertainty in the coefficients. Our results emphasise the need to consider flood types as an important step towards applying flood loss models elsewhere. We argue that failing to do so may unduly generalise the model and systematically bias loss estimations from empirical data.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1148 
KW  - damage
KW  - insurance
KW  - Germany
KW  - transferability
KW  - preparedness
KW  - recovery
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-517743
SN  - 1866-8372
SP  - 1599
EP  - 1614
ER  - 
TY  - JOUR
A1  - Sanhueza-Pino, Katia
A1  - Korup, Oliver
A1  - Hetzel, Ralf
A1  - Munack, Henry
A1  - Weidinger, Johannes T.
A1  - Dunning, Stuart A.
A1  - Ormukov, Cholponbek
A1  - Kubik, Peter W.
T1  - Glacial advances constrained by Be-10 exposure dating of bedrock landslides, Kyrgyz Tien Shan
JF  - Quaternary research : an interdisciplinary journal
N2  - Numerous large landslide deposits occur in the Tien Shan, a tectonically active intraplate orogen in Central Asia. Yet their significance in Quaternary landscape evolution and natural hazard assessment remains unresolved due to the lack of "absolute" age constraints. Here we present the first Be-10 exposure ages for three prominent (>10(7) m(3)) bedrock landslides that blocked major rivers and formed lakes, two of which subsequently breached, in the northern Kyrgyz Tien Shan. Three Be-10 ages reveal that one landslide in the Alamyedin River occurred at 11-15 ka, which is consistent with two C-14 ages of gastropod shells from reworked loess capping the landslide. One large landslide in Aksu River is among the oldest documented in semi-arid continental interiors, with a Be-10 age of 63-67 ka. The Ukok River landslide deposit(s) yielded variable Be-10 ages, which may result from multiple landslides, and inheritance of Be-10. Two Be-10 ages of 8.2 and 5.9 ka suggest that one major landslide occurred in the early to mid-Holocene, followed by at least one other event between 1.5 and 0.4 ka. Judging from the regional glacial chronology, all three landslides have occurred between major regional glacial advances. Whereas Alamyedin and Ukok can be considered as postglacial in this context, Aksu is of interglacial age. None of the landslide deposits show traces of glacial erosion, hence their locations and I Be ages mark maximum extents and minimum ages of glacial advances, respectively. Using toe-to-headwall altitude ratios of 0.4-0.5, we reconstruct minimum equilibrium-line altitudes that exceed previous estimates by as much as 400 m along the moister northern fringe of the Tien Shan. Our data show that deposits from large landslides can provide valuable spatio-temporal constraints for glacial advances in landscapes where moraines and glacial deposits have low preservation potential. (C) 2011 University of Washington. Published by Elsevier Inc. All rights reserved.
KW  - Landslide
KW  - Rock avalanche
KW  - Be-10 exposure dating
KW  - Quaternary glaciations
KW  - Tien Shan
Y1  - 2011
U6  - https://doi.org/10.1016/j.yqres.2011.06.013
SN  - 0033-5894
VL  - 76
IS  - 3
SP  - 295
EP  - 304
PB  - Elsevier
CY  - San Diego
ER  - 
TY  - JOUR
A1  - Schwanghart, Wolfgang
A1  - Bernhardt, Anne
A1  - Stolle, Amelie
A1  - Hoelzmann, Philipp
A1  - Adhikari, Basanta R.
A1  - Andermann, Christoff
A1  - Tofelde, Stefanie
A1  - Merchel, Silke
A1  - Rugel, Georg
A1  - Fort, Monique
A1  - Korup, Oliver
T1  - Repeated catastrophic valley infill following medieval earthquakes in the Nepal Himalaya
JF  - Science
N2  - Geomorphic footprints of past large Himalayan earthquakes are elusive, although they are urgently needed for gauging and predicting recovery times of seismically perturbed mountain landscapes. We present evidence of catastrophic valley infill following at least three medieval earthquakes in the Nepal Himalaya. Radiocarbon dates from peat beds, plant macrofossils, and humic silts in fine-grained tributary sediments near Pokhara, Nepal’s second-largest city, match the timing of nearby M > 8 earthquakes in ~1100, 1255, and 1344 C.E. The upstream dip of tributary valley fills and x-ray fluorescence spectrometry of their provenance rule out local sources. Instead, geomorphic and sedimentary evidence is consistent with catastrophic fluvial aggradation and debris flows that had plugged several tributaries with tens of meters of calcareous sediment from a Higher Himalayan source >60 kilometers away.
Y1  - 2016
U6  - https://doi.org/10.1126/science.aac9865
SN  - 0036-8075
SN  - 1095-9203
VL  - 351
SP  - 147
EP  - 150
PB  - American Assoc. for the Advancement of Science
CY  - Washington
ER  - 
TY  - JOUR
A1  - Schwanghart, Wolfgang
A1  - Ryan, Marie
A1  - Korup, Oliver
T1  - Topographic and seismic constraints on the vulnerability of himalayan hydropower
JF  - Geophysical research letters
N2  - Plain Language Summary The 2015 Gorkha earthquake in Nepal caused severe losses in the hydropower sector. The country temporarily lost similar to 20% of its hydropower capacity, and >30 hydropower projects were damaged. The projects hit hardest were those that were affected by earthquake-triggered landslides. We show that these projects are located along very steep rivers with towering sidewalls that are prone to become unstable during strong seismic ground shaking. A statistical classification based on a topographic metric that expresses river steepness and earthquake ground acceleration is able to approximately predict hydropower damage during future earthquakes, based on successful testing of past cases. Thus, our model enables us to estimate earthquake damages to hydropower projects in other parts of the Himalayas. We find that >10% of the Himalayan drainage network may be unsuitable for hydropower infrastructure given high probabilities of high earthquake damages.
KW  - natural hazards
KW  - hydropower
KW  - landslides
KW  - Himalaya
Y1  - 2018
U6  - https://doi.org/10.1029/2018GL079173
SN  - 0094-8276
SN  - 1944-8007
VL  - 45
IS  - 17
SP  - 8985
EP  - 8992
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Schwanghart, Wolfgang
A1  - Worni, Raphael
A1  - Huggel, Christian
A1  - Stoffel, Markus
A1  - Korup, Oliver
T1  - Uncertainty in the Himalayan energy-water nexus: estimating regional exposure to glacial lake outburst floods
JF  - Environmental research letters
N2  - Himalayan water resources attract a rapidly growing number of hydroelectric power projects (HPP) to satisfy Asia's soaring energy demands. Yet HPP operating or planned in steep, glacier-fed mountain rivers face hazards of glacial lake outburst floods (GLOFs) that can damage hydropower infrastructure, alter water and sediment yields, and compromise livelihoods downstream. Detailed appraisals of such GLOF hazards are limited to case studies, however, and a more comprehensive, systematic analysis remains elusive. To this end we estimate the regional exposure of 257 Himalayan HPP to GLOFs, using a flood-wave propagation model fed by Monte Carlo-derived outburst volumes of >2300 glacial lakes. We interpret the spread of thus modeled peak discharges as a predictive uncertainty that arises mainly from outburst volumes and dam-breach rates that are difficult to assess before dams fail. With 66% of sampled HPP are on potential GLOF tracks, up to one third of these HPP could experience GLOF discharges well above local design floods, as hydropower development continues to seek higher sites closer to glacial lakes. We compute that this systematic push of HPP into headwaters effectively doubles the uncertainty about GLOF peak discharge in these locations. Peak discharges farther downstream, in contrast, are easier to predict because GLOF waves attenuate rapidly. Considering this systematic pattern of regional GLOF exposure might aid the site selection of future Himalayan HPP. Our method can augment, and help to regularly update, current hazard assessments, given that global warming is likely changing the number and size of Himalayan meltwater lakes.
KW  - hydropower
KW  - water resources
KW  - glacial hazards
KW  - glacial lake outburst floods
KW  - Himalayas
Y1  - 2016
U6  - https://doi.org/10.1088/1748-9326/11/7/074005
SN  - 1748-9326
VL  - 11
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - GEN
A1  - Schwanghart, Wolfgang
A1  - Worni, Raphael
A1  - Huggel, Christian
A1  - Stoffel, Markus
A1  - Korup, Oliver
T1  - Uncertainty in the Himalayan energy–water nexus
BT  - estimating regional exposure to glacial lake outburst floods
N2  - Himalayan water resources attract a rapidly growing number of hydroelectric power projects (HPP) to satisfy Asia's soaring energy demands. Yet HPP operating or planned in steep, glacier-fed mountain rivers face hazards of glacial lake outburst floods (GLOFs) that can damage hydropower infrastructure, alter water and sediment yields, and compromise livelihoods downstream. Detailed appraisals of such GLOF hazards are limited to case studies, however, and a more comprehensive, systematic analysis remains elusive. To this end we estimate the regional exposure of 257 Himalayan HPP to GLOFs, using a flood-wave propagation model fed by Monte Carlo-derived outburst volumes of >2300 glacial lakes. We interpret the spread of thus modeled peak discharges as a predictive uncertainty that arises mainly from outburst volumes and dam-breach rates that are difficult to assess before dams fail. With 66% of sampled HPP are on potential GLOF tracks, up to one third of these HPP could experience GLOF discharges well above local design floods, as hydropower development continues to seek higher sites closer to glacial lakes. We compute that this systematic push of HPP into headwaters effectively doubles the uncertainty about GLOF peak discharge in these locations. Peak discharges farther downstream, in contrast, are easier to predict because GLOF waves attenuate rapidly. Considering this systematic pattern of regional GLOF exposure might aid the site selection of future Himalayan HPP. Our method can augment, and help to regularly update, current hazard assessments, given that global warming is likely changing the number and size of Himalayan meltwater lakes.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 266 
KW  - hydropower
KW  - water resources
KW  - glacial hazards
KW  - glacial lake outburst floods
KW  - Himalayas
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-97136
ER  - 
TY  - JOUR
A1  - Schwanghart, Wolfgang
A1  - Worni, Raphael
A1  - Huggel, Christian
A1  - Stoffel, Markus
A1  - Korup, Oliver
T1  - Uncertainty in the Himalayan energy–water nexus
BT  - estimating regional exposure to glacial lake outburst floods
JF  - Environmental research letters : ERL
N2  - Himalayan water resources attract a rapidly growing number of hydroelectric power projects (HPP) to satisfy Asia's soaring energy demands. Yet HPP operating or planned in steep, glacier-fed mountain rivers face hazards of glacial lake outburst floods (GLOFs) that can damage hydropower infrastructure, alter water and sediment yields, and compromise livelihoods downstream. Detailed appraisals of such GLOF hazards are limited to case studies, however, and a more comprehensive, systematic analysis remains elusive. To this end we estimate the regional exposure of 257 Himalayan HPP to GLOFs, using a flood-wave propagation model fed by Monte Carlo-derived outburst volumes of >2300 glacial lakes. We interpret the spread of thus modeled peak discharges as a predictive uncertainty that arises mainly from outburst volumes and dam-breach rates that are difficult to assess before dams fail. With 66% of sampled HPP are on potential GLOF tracks, up to one third of these HPP could experience GLOF discharges well above local design floods, as hydropower development continues to seek higher sites closer to glacial lakes. We compute that this systematic push of HPP into headwaters effectively doubles the uncertainty about GLOF peak discharge in these locations. Peak discharges farther downstream, in contrast, are easier to predict because GLOF waves attenuate rapidly. Considering this systematic pattern of regional GLOF exposure might aid the site selection of future Himalayan HPP. Our method can augment, and help to regularly update, current hazard assessments, given that global warming is likely changing the number and size of Himalayan meltwater lakes.
KW  - Himalayas
KW  - glacial hazards
KW  - glacial lake outburst floods
KW  - hydropower
KW  - water resources
Y1  - 2016
U6  - https://doi.org/10.1088/1748-9326/11/7/074005
SN  - 1748-9326
VL  - 11
PB  - IOP Publ.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Schönfeldt, Elisabeth
A1  - Pánek, Tomáš
A1  - Winocur, Diego
A1  - Silhan, Karel
A1  - Korup, Oliver
T1  - Postglacial Patagonian mass movement
BT  - from rotational slides and spreads to earthflows
JF  - Geomorphology : an international journal on pure and applied geomorphology
N2  - Many of the volcanic plateau margins of the eastern, formerly glaciated, foreland of the Patagonian Andes are undermined by giant landslides (>= 10(8) m(3)). One cluster of such landslides extends along the margin of the Meseta del Lago Buenos Aires (MLBA) plateau that is formed mainly by Neogene-Quaternary basalts. The dry climate is at odds with numerous >2-km long earthflows nested within older and larger compound landslides. We present a hydrological analysis, a detailed geomorphic map, interpretations of exposed landslide interiors, and radiocarbon dating of the El Mirador landslide, which is one of the largest and morphologically most representative landslide. We find that the presence of lakes on top of the plateau, causing low infiltration rates, correlates negatively with the abundance of earthflows on compound landslides along the plateau margins. Field outcrops show that the pattern of compound landslides and earthflows is likely controlled by groundwater seepage at the contact between the basalts and underlying soft Miocene molasse. Numerous peat bogs store water and sediment and are more abundant in earthflow-affected areas than in their contributing catchment areas. <br /> Radiocarbon dates indicate that these earthflows displaced metre-thick layers of peat in the late Holocene (<2.5 ka). We conclude that earthflows of the MLBA plateau might be promising proxies of past hydroclimatic conditions in the Patagonian foreland, if strong earthquakes or gradual crustal stress changes due to glacioisostatic rebound can be ruled out.
KW  - landslide
KW  - lateral spread
KW  - earthflow
KW  - Patagonia
Y1  - 2020
U6  - https://doi.org/10.1016/j.geomorph.2020.107316
SN  - 0169-555X
SN  - 1872-695X
VL  - 367
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Schönfeldt, Elisabeth
A1  - Winocur, Diego
A1  - Pánek, Tomáš
A1  - Korup, Oliver
T1  - Deep learning reveals one of Earth's largest landslide terrain in Patagonia
JF  - Earth & planetary science letters
N2  - Hundreds of basaltic plateau margins east of the Patagonian Cordillera are undermined by numerous giant slope failures. However, the overall extent of this widespread type of plateau collapse remains unknown and incompletely captured in local maps. To detect giant slope failures consistently throughout the region, we train two convolutional neural networks (CNNs), AlexNet and U-Net, with Sentinel-2 optical data and TanDEM-X topographic data on elevation, surface roughness, and curvature. We validated the performance of these CNNs with independent testing data and found that AlexNet performed better when learned on topographic data, and UNet when learned on optical data. AlexNet predicts a total landslide area of 12,000 km2 in a study area of 450,000 km2, and thus one of Earth's largest clusters of giant landslides. These are mostly lateral spreads and rotational failures in effusive rocks, particularly eroding the margins of basaltic plateaus; some giant landslides occurred along shores of former glacial lakes, but are least prevalent in Quaternary sedimentary rocks. Given the roughly comparable topographic, climatic, and seismic conditions in our study area, we infer that basalts topping weak sedimentary rocks may have elevated potential for large-scale slope failure. Judging from the many newly detected and previously unknown landslides, we conclude that CNNs can be a valuable tool to detect large-scale slope instability at the regional scale. However, visual inspection is still necessary to validate results and correctly outline individual landslide source and deposit areas.
KW  - landslide detection
KW  - convolutional neural network
KW  - Patagonia
Y1  - 2022
U6  - https://doi.org/10.1016/j.epsl.2022.117642
SN  - 0012-821X
SN  - 1385-013X
VL  - 593
PB  - Elsevier
CY  - Amsterdam [u.a.]
ER  - 
TY  - JOUR
A1  - Stolle, Amelie
A1  - Bernhardt, Anne
A1  - Schwanghart, Wolfgang
A1  - Hoelzmann, Philipp
A1  - Adhikari, Basanta R.
A1  - Fort, Monique
A1  - Korup, Oliver
T1  - Catastrophic valley fills record large Himalayan earthquakes, Pokhara, Nepal
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
KW  - Catastrophic valley infill
KW  - Great Himalayan earthquakes
KW  - Radiocarbon age dating
KW  - Provenance analysis
KW  - Paleoseismology
KW  - Nepal
Y1  - 2017
U6  - https://doi.org/10.1016/j.quascirev.2017.10.015
SN  - 0277-3791
VL  - 177
SP  - 88
EP  - 103
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Stolle, Amelie
A1  - Langer, Maria
A1  - Blöthe, Jan Henrik
A1  - Korup, Oliver
T1  - On predicting debris flows in arid mountain belts
JF  - Global and planetary change
N2  - The use of topographic metrics for estimating the susceptibility to, and reconstructing the characteristics of, debris flows has a long research tradition, although largely devoted to humid mountainous terrain. The exceptional 2010 monsoonal rainstorms in the high-altitude mountain desert of Ladakh and Zanskar, NW India, were a painful reminder of how susceptible arid regions are to rainfall-triggered flash floods, landslides, and debris flows. The rainstorms of August 4-6 triggered numerous debris flows, killing 182 people, devastating 607 houses, and more than 10 bridges around Ladakh's capital of Leh. The lessons from this disaster motivated us to revisit methods of predicting (a) flow parameters such as peak discharge and maximum velocity from field and remote sensing data, and (b) the susceptibility to debris flows from catchment morphometry. We focus on quantifying uncertainties tied to these approaches. Comparison of high-resolution satellite images pre- and post-dating the 2010 rainstorm reveals the extent of damage and catastrophic channel widening. Computations based on these geomorphic markers indicate maximum flow velocities of 1.6-6.7 m s(-1) with runout of up to similar to 10 km on several alluvial fans that sustain most of the region's settlements. We estimate median peak discharges of 310-610 m(3) s(-1), which are largely consistent with previous estimates. Monte Carlo-based error propagation for a single given flow-reconstruction method returns a variance in discharge similar to one derived from juxtaposing several different flow reconstruction methods. We further compare discriminant analysis, classification tree modelling, and Bayesian logistic regression to predict debris-flow susceptibility from morphometric variables of 171 catchments in the Ladakh Range. These methods distinguish between fluvial and debris flow-prone catchments at similar success rates, but Bayesian logistic regression allows quantifying uncertainties and relationships between potential predictors. We conclude that, in order to be robust and reliable, morphometric reconstruction of debris-flow properties and susceptibility requires careful assessment and reporting of errors and uncertainties. (C) 2015 Elsevier B.V. All rights reserved.
KW  - debris flow
KW  - peak discharge
KW  - channel geometry
KW  - geomorphometry
KW  - Bayesian logistic regression
KW  - Transhimalaya
Y1  - 2015
U6  - https://doi.org/10.1016/j.gloplacha.2014.12.005
SN  - 0921-8181
SN  - 1872-6364
VL  - 126
SP  - 1
EP  - 13
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Stolle, Amelie
A1  - Schwanghart, Wolfgang
A1  - Andermann, Christoff
A1  - Bernhardt, Anne
A1  - Fort, Monique
A1  - Jansen, John D.
A1  - Wittmann, Hella
A1  - Merchel, Silke
A1  - Rugel, Georg
A1  - Adhikari, Basanta Raj
A1  - Korup, Oliver
T1  - Protracted river response to medieval earthquakes
JF  - Earth surface processes and landforms : the journal of the British Geomorphological Research Group
N2  - Mountain rivers respond to strong earthquakes by rapidly aggrading to accommodate excess sediment delivered by co-seismic landslides. Detailed sediment budgets indicate that rivers need several years to decades to recover from seismic disturbances, depending on how recovery is defined. We examine three principal proxies of river recovery after earthquake-induced sediment pulses around Pokhara, Nepal's second largest city. Freshly exhumed cohorts of floodplain trees in growth position indicate rapid and pulsed sedimentation that formed a fan covering 150 km2 in a Lesser Himalayan basin with tens of metres of debris between the 11th and 15th centuries AD. Radiocarbon dates of buried trees are consistent with those of nearby valley deposits linked to major medieval earthquakes, such that we can estimate average rates of re-incision since. We combine high-resolution digital elevation data, geodetic field surveys, aerial photos, and dated tree trunks to reconstruct geomorphic marker surfaces. The volumes of sediment relative to these surfaces require average net sediment yields of up to 4200 t km–2 yr–1 for the 650 years since the last inferred earthquake-triggered sediment pulse. The lithological composition of channel bedload differs from that of local bedrock, confirming that rivers are still mostly evacuating medieval valley fills, locally incising at rates of up to 0.2 m yr–1. Pronounced knickpoints and epigenetic gorges at tributary junctions further illustrate the protracted fluvial response; only the distal portions of the earthquake-derived sediment wedges have been cut to near their base. Our results challenge the notion that mountain rivers recover speedily from earthquakes within years to decades. The valley fills around Pokhara show that even highly erosive Himalayan rivers may need more than several centuries to adjust to catastrophic perturbations. Our results motivate some rethinking of post-seismic hazard appraisals and infrastructural planning in active mountain regions.
KW  - fluvial response
KW  - sediment yield
KW  - earthquakes
KW  - Nepal
KW  - Himalaya
Y1  - 2018
U6  - https://doi.org/10.1002/esp.4517
SN  - 0197-9337
SN  - 1096-9837
VL  - 44
IS  - 1
SP  - 331
EP  - 341
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Struck, Martin
A1  - Andermann, Christoff
A1  - Hovius, Niels
A1  - Korup, Oliver
A1  - Turowski, Jens M.
A1  - Bista, Raj
A1  - Pandit, Hari P.
A1  - Dahal, Ranjan K.
T1  - Monsoonal hillslope processes determine grain size-specific suspended sediment fluxes in a trans-Himalayan river
JF  - Geophysical research letters
N2  - Sediments in rivers record the dynamics of erosion processes. While bulk sediment fluxes are easily and routinely obtained, sediment caliber remains underexplored when inferring erosion mechanisms. Yet sediment grain size distributions may be the key to discriminating their origin. We have studied grain size-specific suspended sediment fluxes in the Kali Gandaki, a major trans-Himalayan river. Two strategically located gauging stations enable tracing of sediment caliber on either side of the Himalayan orographic barrier. The data show that fine sediment input into the northern headwaters is persistent, while coarse sediment comes from the High Himalayas during the summer monsoon. A temporally matching landslide inventory similarly indicates the prominence of monsoon-driven hillslope mass wasting. Thus, mechanisms of sediment supply can leave strong traces in the fluvial caliber, which could project well beyond the mountain front and add to the variability of the sedimentary record of orogen erosion.
KW  - Himalayas
KW  - erosion
KW  - grain size
KW  - suspended sediments
KW  - landslide
KW  - river transport
Y1  - 2015
U6  - https://doi.org/10.1002/2015GL063360
SN  - 0094-8276
SN  - 1944-8007
VL  - 42
IS  - 7
SP  - 2302
EP  - 2308
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Uhlmann, Manuela
A1  - Korup, Oliver
A1  - Huggel, Christian
A1  - Fischer, Luzia
A1  - Kargel, Jeffrey S.
T1  - Supra-glacial deposition and flux of catastrophic rock-slope failure debris, south-central Alaska
JF  - Earth surface processes and landforms : the journal of the British Geomorphological Research Group
N2  - The ongoing debate over the effects of global environmental change on Earth's cryosphere calls for detailed knowledge about process rates and their variability in cold environments. In this context, appraisals of the coupling between glacier dynamics and para-glacial erosion rates in tectonically active mountains remain rare. We contribute to filling this knowledge gap and present an unprecedented regional-scale inventory of supra-glacial sediment flux and hillslope erosion rates inferred from an analysis of 123 large (> 0 center dot 1km2) catastrophic bedrock landslides that fell onto glaciers in the Chugach Mountains, Alaska, as documented by satellite images obtained between 1972 to 2008. Assuming these supra-glacial landslide deposits to be passive strain markers we infer minimum decadal-scale sediment yields of 190 to 7400tkm-2yr-1 for a given glacier-surface cross-section impacted by episodic rock-slope failure. These rates compare to reported fluvial sediment yields in many mountain rivers, but are an order of magnitude below the extreme sediment yields measured at the snouts of Alaskan glaciers, indicating that the bulk of debris discharged derives from en-glacial, sub-glacial or ice-proximal sources. We estimate an average minimum para-glacial erosion rate by large, episodic rock-slope failures at 0 center dot 5-0 center dot 7mmyr-1 in the Chugach Mountains over a 50-yr period, with earthquakes likely being responsible for up to 73% of this rate. Though ranking amongst the highest decadal landslide erosion rates for this size of study area worldwide, our inferred rates of hillslope erosion in the Chugach Mountains remain an order of magnitude below the pace of extremely rapid glacial sediment export and glacio-isostatic surface uplift previously reported from the region.
KW  - glacier
KW  - landslide
KW  - erosion rate
KW  - sediment yield
KW  - Alaska
Y1  - 2013
U6  - https://doi.org/10.1002/esp.3311
SN  - 0197-9337
VL  - 38
IS  - 7
SP  - 675
EP  - 682
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Ulloa, Hector
A1  - Irourne, Andres
A1  - Picco, Lorenzo
A1  - Korup, Oliver
A1  - Lenzi, Mario Aristide
A1  - Mao, Luca
A1  - Ravazzolo, Diego
T1  - Massive biomass flushing despite modest channel response in the Rayas River following the 2008 eruption of Chaiten volcano, Chile
JF  - Geomorphology : an international journal on pure and applied geomorphology
N2  - The 2008 eruption of Chaiten volcano in southern Chile severely impacted several densely forested river catchments by supplying excess pyroclastic sediment to the channel networks. Our aim is to substantiate whether and how channel geometry and forest stands changed in the Rayas River following the sudden input of pyroclastic sediment. We measured the resulting changes to channel geometry and riparian forest stands along 17.6 km of the impacted gravel-bed Rayas River (294 km(2)) from multiple high-resolution satellite images, aerial photographs, and fieldwork to quantify yield volume characteristics of the forest stands. Limited channel changes during the last 60 years before the eruption reflect a dynamic equilibrium condition of the river corridor, despite the high annual precipitation and the sediment supply from Chaiten and Michinmahuida volcanoes in the headwaters. Images taken in 1945, 2004, and 2005 show that total size of the vegetated channel islands nearly doubled between 1945 and 2004 and remained unchanged between 2004 and 2005. Pyroclastic sediment entering the Rayas River after the 2008 eruption caused only minor average channel widening (7%), but killed all island vegetation in the study reach. Substantial shifts in the size distribution of in-channel vegetation patches reflect losses in total island area of 46% from 2005 to 2009 and an additional 34% from 2009 to 2012. The estimated pulsed release of organic carbon into the channel, mainly in the form of large wood from obliterated island and floodplain forests, was 78-400 tC/km/y and surpasses most documented yields from small mountainous catchments with similar rainfall, forest cover, and disturbance history, while making up between 20% and 60% of the annual carbon burial rate of fluvial sediments in the northern Patagonian fjords. We conclude that the carbon footprint of the 2008 Chaiten eruption on the Rayas River was more significant than the measured geomorphic impacts on channel geometry for the first five years following disturbance. The modest post-eruptive geomorphic response in this river is a poor indicator of its biogeochemical response. (C) 2015 Elsevier B.V. All rights reserved.
KW  - Chaiten volcano
KW  - Forest disturbance
KW  - Channel island
KW  - Organic carbon
Y1  - 2015
U6  - https://doi.org/10.1016/j.geomorph.2015.09.019
SN  - 0169-555X
SN  - 1872-695X
VL  - 250
SP  - 397
EP  - 406
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Veh, Georg
A1  - Korup, Oliver
A1  - Roessner, Sigrid
A1  - Walz, Ariane
T1  - Detecting Himalayan glacial lake outburst floods from Landsat time series
JF  - Remote sensing of environment : an interdisciplinary journal
N2  - Several thousands of moraine-dammed and supraglacial lakes spread over the Hindu Kush Himalayan (HKH) region, and some have grown rapidly in past decades due to glacier retreat. The sudden emptying of these lakes releases large volumes of water and sediment in destructive glacial lake outburst floods (GLOFs), one of the most publicised natural hazards to the rapidly growing Himalayan population. Despite the growing number and size of glacial lakes, the frequency of documented GLOFs is remarkably constant. We explore this possible reporting bias and offer a new processing chain for establishing a more complete Himalayan GLOF inventory. We make use of the full seasonal archive of Landsat images between 1988 and 2016, and track automatically where GLOFs left shrinking water bodies, and tails of sediment at high elevations. We trained a Random Forest classifier to generate fuzzy land cover maps for 2491 images, achieving overall accuracies of 91%. We developed a likelihood-based change point technique to estimate the timing of GLOFs at the pixel scale. Our method objectively detected ten out of eleven documented GLOFs, and another ten lakes that gave rise to previously unreported GLOFs. We thus nearly doubled the existing GLOF record for a study area covering similar to 10% of the HKH region. Remaining challenges for automatically detecting GLOFs include image insufficiently accurate co-registration, misclassifications in the land cover maps and image noise from clouds, shadows or ice. Yet our processing chain is robust and has the potential for being applied on the greater HKH and mountain ranges elsewhere, opening the door for objectively expanding the knowledge base on GLOF activity over the past three decades.
KW  - Random Forest
KW  - Fuzzy classification
KW  - Land cover maps
KW  - Change detection
KW  - Change points
KW  - Lakes
KW  - Sediment tails
KW  - Hindu Kush Himalayas (HKH)
Y1  - 2018
U6  - https://doi.org/10.1016/j.rse.2017.12.025
SN  - 0034-4257
SN  - 1879-0704
VL  - 207
SP  - 84
EP  - 97
PB  - Elsevier
CY  - New York
ER  - 
TY  - JOUR
A1  - Veh, Georg
A1  - Korup, Oliver
A1  - von Specht, Sebastian
A1  - Rößner, Sigrid
A1  - Walz, Ariane
T1  - Unchanged frequency of moraine-dammed glacial lake outburst floods in the Himalaya
JF  - Nature climate change
N2  - Shrinking glaciers in the Hindu Kush-Karakoram-Himalaya-Nyainqentanglha (HKKHN) region have formed several thousand moraine-dammed glacial lakes(1-3), some of these having grown rapidly in past decades(3,4). This growth may promote more frequent and potentially destructive glacial lake outburst floods (GLOFs)(5-7). Testing this hypothesis, however, is confounded by incomplete databases of the few reliable, though selective, case studies. Here we present a consistent Himalayan GLOF inventory derived automatically from all available Landsat imagery since the late 1980s. We more than double the known GLOF count and identify the southern Himalayas as a hotspot region, compared to the more rarely affected Hindu Kush-Karakoram ranges. Nevertheless, the average annual frequency of 1.3 GLOFs has no credible posterior trend despite reported increases in glacial lake areas in most of the HKKHN3,8, so that GLOF activity per unit lake area has decreased since the late 1980s. We conclude that learning more about the frequency and magnitude of outburst triggers, rather than focusing solely on rapidly growing glacial lakes, might improve the appraisal of GLOF hazards.
KW  - Climate change
KW  - Cryospheric science
KW  - Environmental impact
KW  - Geomorphology
Y1  - 2019
U6  - https://doi.org/10.1038/s41558-019-0437-5
SN  - 1758-678X
SN  - 1758-6798
VL  - 9
IS  - 5
SP  - 379
EP  - 383
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Veh, Georg
A1  - Korup, Oliver
A1  - Walz, Ariane
T1  - Hazard from Himalayan glacier lake outburst floods
JF  - Proceedings of the National Academy of Sciences of the United States of America : PNAS
N2  - Sustained glacier melt in the Himalayas has gradually spawned more than 5,000 glacier lakes that are dammed by potentially unstable moraines. When such dams break, glacier lake outburst floods (GLOFs) can cause catastrophic societal and geomorphic impacts. We present a robust probabilistic estimate of average GLOFs return periods in the Himalayan region, drawing on 5.4 billion simulations. We find that the 100-y outburst flood has an average volume of 33.5(+3.7)/(-3.7) x 10(6) m(3) (posterior mean and 95% highest density interval [HDI]) with a peak discharge of 15,600(+2.000)/(-1,800) m(3).S-1. Our estimated GLOF hazard is tied to the rate of historic lake outbursts and the number of present lakes, which both are highest in the Eastern Himalayas. There, the estimated 100-y GLOF discharge (similar to 14,500 m(3).s(-1)) is more than 3 times that of the adjacent Nyainqentanglha Mountains, and at least an order of magnitude higher than in the Hindu Kush, Karakoram, and Western Himalayas. The GLOF hazard may increase in these regions that currently have large glaciers, but few lakes, if future projected ice loss generates more unstable moraine-dammed lakes than we recognize today. Flood peaks from GLOFs mostly attenuate within Himalayan headwaters, but can rival monsoon-fed discharges in major rivers hundreds to thousands of kilometers downstream. Projections of future hazard from meteorological floods need to account for the extreme runoffs during lake outbursts, given the increasing trends in population, infrastructure, and hydropower projects in Himalayan headwaters.
KW  - atmospheric warming
KW  - meltwater lakes
KW  - GLOF
KW  - extreme-value statistics
KW  - Bayesian modeling
Y1  - 2019
U6  - https://doi.org/10.1073/pnas.1914898117
SN  - 0027-8424
VL  - 117
IS  - 2
SP  - 907
EP  - 912
PB  - National Academy of Sciences
CY  - Washington
ER  - 
TY  - GEN
A1  - Veh, Georg
A1  - Lützow, Natalie
A1  - Kharlamova, Varvara
A1  - Petrakov, Dmitry
A1  - Hugonnet, Romain
A1  - Korup, Oliver
T1  - Trends, Breaks, and Biases in the Frequency of Reported Glacier Lake Outburst Floods
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Thousands of glacier lakes have been forming behind natural dams in high mountains following glacier retreat since the early 20th century. Some of these lakes abruptly released pulses of water and sediment with disastrous downstream consequences. Yet it remains unclear whether the reported rise of these glacier lake outburst floods (GLOFs) has been fueled by a warming atmosphere and enhanced meltwater production, or simply a growing research effort. Here we estimate trends and biases in GLOF reporting based on the largest global catalog of 1,997 dated glacier-related floods in six major mountain ranges from 1901 to 2017. We find that the positive trend in the number of reported GLOFs has decayed distinctly after a break in the 1970s, coinciding with independently detected trend changes in annual air temperatures and in the annual number of field-based glacier surveys (a proxy of scientific reporting). We observe that GLOF reports and glacier surveys decelerated, while temperature rise accelerated in the past five decades. Enhanced warming alone can thus hardly explain the annual number of reported GLOFs, suggesting that temperature-driven glacier lake formation, growth, and failure are weakly coupled, or that outbursts have been overlooked. Indeed, our analysis emphasizes a distinct geographic and temporal bias in GLOF reporting, and we project that between two to four out of five GLOFs on average might have gone unnoticed in the early to mid-20th century. We recommend that such biases should be considered, or better corrected for, when attributing the frequency of reported GLOFs to atmospheric warming.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1264 
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-561005
SN  - 1866-8372
SP  - 1
EP  - 14
PB  - Universitätsverlag Potsdam
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Veh, Georg
A1  - Lützow, Natalie
A1  - Kharlamova, Varvara
A1  - Petrakov, Dmitry
A1  - Hugonnet, Romain
A1  - Korup, Oliver
T1  - Trends, Breaks, and Biases in the Frequency of Reported Glacier Lake Outburst Floods
JF  - Earth's Future
N2  - Thousands of glacier lakes have been forming behind natural dams in high mountains following glacier retreat since the early 20th century. Some of these lakes abruptly released pulses of water and sediment with disastrous downstream consequences. Yet it remains unclear whether the reported rise of these glacier lake outburst floods (GLOFs) has been fueled by a warming atmosphere and enhanced meltwater production, or simply a growing research effort. Here we estimate trends and biases in GLOF reporting based on the largest global catalog of 1,997 dated glacier-related floods in six major mountain ranges from 1901 to 2017. We find that the positive trend in the number of reported GLOFs has decayed distinctly after a break in the 1970s, coinciding with independently detected trend changes in annual air temperatures and in the annual number of field-based glacier surveys (a proxy of scientific reporting). We observe that GLOF reports and glacier surveys decelerated, while temperature rise accelerated in the past five decades. Enhanced warming alone can thus hardly explain the annual number of reported GLOFs, suggesting that temperature-driven glacier lake formation, growth, and failure are weakly coupled, or that outbursts have been overlooked. Indeed, our analysis emphasizes a distinct geographic and temporal bias in GLOF reporting, and we project that between two to four out of five GLOFs on average might have gone unnoticed in the early to mid-20th century. We recommend that such biases should be considered, or better corrected for, when attributing the frequency of reported GLOFs to atmospheric warming.
Y1  - 2022
U6  - https://doi.org/10.1029/2021EF002426
SN  - 2328-4277
VL  - 10
SP  - 1
EP  - 14
PB  - Wiley-Blackwell
CY  - Hoboken, New Jersey, United States
ET  - 3
ER  - 
TY  - JOUR
A1  - Vogel, Kristin
A1  - Ozturk, Ugur
A1  - Riemer, Adrian
A1  - Laudan, Jonas
A1  - Sieg, Tobias
A1  - Wendi, Dadiyorto
A1  - Agarwal, Ankit
A1  - Roezer, Viktor
A1  - Korup, Oliver
A1  - Thieken, Annegret
T1  - Die Sturzflut von Braunsbach am 29. Mai 2016 – Entstehung, Ablauf und Schäden eines „Jahrhundertereignisses“
T1  - The Braunsbach Flashflood of Mai 29th, 2016-Origin, Pathways and Impacts of an Extreme Hydro-Meteorological Event
BT  - Teil 2: Geomorphologische Prozesse und Schadensanalyse
BT  - Part 2: Geomorphological Processes and Damage Analysis
JF  - Hydrologie und Wasserbewirtschaftung
N2  - Am Abend des 29. Mai 2016 wurde der Ort Braunsbach im Landkreis Schwäbisch-Hall (Baden-Württemberg) von einer Sturzflut getroffen, bei der mehrere Häuser stark beschädigt oder zerstört wurden. Die Sturzflut war eine der Unwetterfolgen, die im Frühsommer 2016 vom Tiefdruckgebiet Elvira ausgelöst wurden. Der vorliegende Bericht ist der zweite Teil einer Doppelveröffentlichung, welche die Ergebnisse zur Untersuchung des Sturzflutereignisses im Rahmen des DFG-Graduiertenkollegs “Naturgefahren und Risiken in einer sich verändernden Welt” (NatRiskChange, GRK 2043/1) der Universität Potsdam präsentiert. Während Teil 1 die meteorologischen und hydrologischen Ereignisse analysiert, fokussiert Teil 2 auf die geomorphologischen Prozesse und die verursachten Gebäudeschäden. Dazu wurden Ursprung und Ausmaß des während des Sturzflutereignisses mobilisierten und in den Ort getragenen Materials untersucht. Des Weiteren wurden zu 96 betroffenen Gebäuden Daten zum Schadensgrad sowie Prozess- und Gebäudecharakteristika aufgenommen und ausgewertet. Die Untersuchungen zeigen, dass bei der Betrachtung von Hochwassergefährdung die Berücksichtigung von Sturzfluten und ihrer speziellen Charakteristika, wie hoher Feststofftransport und sprunghaftes Verhalten insbesondere in bebautem Gelände, wesentlich ist, um effektive Schutzmaßnahmen ergreifen zu können.
N2  - A severe flash flood event hit the town of Braunsbach (Baden-Wurttemberg, Germany) on the evening of May 29, 2016, heavily damaging and destroying several dozens of buildings. It was only one of several disastrous events in Central Europe caused by the low-pressure system "Elvira". The DFG Graduate School "Natural hazards and risks in a changing world" (NatRiskChange, GRK 2043/1) at the University of Potsdam investigated the Braunsbach flash flood as a recent showcase for catastrophic events triggered by severe weather. This contribution is part two of a back-to-back publication on the results of this storm event. While part 1 analyses the meteorological and hydrological situation, part 2 concentrates on the geomorphological aspects and damage to buildings. The study outlines the origin and amount of material that was mobilized and transported into the town by the flood, and analyses damage data collected for 96 affected buildings, describing the degree of impact, underlying processes, and building characteristics. Due to the potentially high sediment load of flash floods and their non-steady and non-uniform flow especially in built-up areas, the damaging processes differ from those of clear water floods. The results underline the need to consider flash floods and their specific behaviour in flood hazard assessments.
KW  - flash flood
KW  - flood risk
KW  - damaging processes
KW  - debris flow
KW  - erosion
KW  - landslides
KW  - Braunsbach
KW  - Sturzflut
KW  - Hochwassergefährdung
KW  - Schadensprozesse
KW  - Erosion
KW  - Hangrutschungen
Y1  - 2017
U6  - https://doi.org/10.5675/HyWa_2017,3_2
SN  - 1439-1783
VL  - 61
IS  - 3
SP  - 163
EP  - 175
PB  - Bundesanst. für Gewässerkunde
CY  - Koblenz
ER  - 
TY  - JOUR
A1  - Vogel, Kristin
A1  - Riggelsen, Carsten
A1  - Korup, Oliver
A1  - Scherbaum, Frank
T1  - Bayesian network learning for natural hazard analyses
JF  - Natural hazards and earth system sciences
N2  - Modern natural hazards research requires dealing with several uncertainties that arise from limited process knowledge, measurement errors, censored and incomplete observations, and the intrinsic randomness of the governing processes. Nevertheless, deterministic analyses are still widely used in quantitative hazard assessments despite the pitfall of misestimating the hazard and any ensuing risks.
 In this paper we show that Bayesian networks offer a flexible framework for capturing and expressing a broad range of uncertainties encountered in natural hazard assessments. Although Bayesian networks are well studied in theory, their application to real-world data is far from straightforward, and requires specific tailoring and adaptation of existing algorithms. We offer suggestions as how to tackle frequently arising problems in this context and mainly concentrate on the handling of continuous variables, incomplete data sets, and the interaction of both. By way of three case studies from earthquake, flood, and landslide research, we demonstrate the method of data-driven Bayesian network learning, and showcase the flexibility, applicability, and benefits of this approach.
 Our results offer fresh and partly counterintuitive insights into well-studied multivariate problems of earthquake-induced ground motion prediction, accurate flood damage quantification, and spatially explicit landslide prediction at the regional scale. In particular, we highlight how Bayesian networks help to express information flow and independence assumptions between candidate predictors. Such knowledge is pivotal in providing scientists and decision makers with well-informed strategies for selecting adequate predictor variables for quantitative natural hazard assessments.
Y1  - 2014
U6  - https://doi.org/10.5194/nhess-14-2605-2014
SN  - 1561-8633
VL  - 14
IS  - 9
SP  - 2605
EP  - 2626
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - von Specht, Sebastian
A1  - Öztürk, Ugur
A1  - Veh, Georg
A1  - Cotton, Fabrice Pierre
A1  - Korup, Oliver
T1  - Effects of finite source rupture on landslide triggering
BT  - the 2016 M-w 7.1 Kumamoto earthquake
JF  - Solid earth
N2  - The propagation of a seismic rupture on a fault introduces spatial variations in the seismic wave field surrounding the fault. This directivity effect results in larger shaking amplitudes in the rupture propagation direction. Its seismic radiation pattern also causes amplitude variations between the strike-normal and strike-parallel components of horizontal ground motion. We investigated the landslide response to these effects during the 2016 Kumamoto earthquake (M-w 7.1) in central Kyushu (Japan). Although the distribution of some 1500 earthquake-triggered landslides as a function of rupture distance is consistent with the observed Arias intensity, the landslides were more concentrated to the northeast of the southwest-northeast striking rupture. We examined several landslide susceptibility factors: hillslope inclination, the median amplification factor (MAF) of ground shaking, lithology, land cover, and topographic wetness. None of these factors sufficiently explains the landslide distribution or orientation (aspect), although the landslide head scarps have an elevated hillslope inclination and MAF. We propose a new physics-based ground-motion model (GMM) that accounts for the seismic rupture effects, and we demonstrate that the low-frequency seismic radiation pattern is consistent with the overall landslide distribution. Its spatial pattern is influenced by the rupture directivity effect, whereas landslide aspect is influenced by amplitude variations between the fault-normal and fault-parallel motion at frequencies < 2 Hz. This azimuth dependence implies that comparable landslide concentrations can occur at different distances from the rupture. This quantitative link between the prevalent landslide aspect and the low-frequency seismic radiation pattern can improve coseismic landslide hazard assessment.
Y1  - 2019
U6  - https://doi.org/10.5194/se-10-463-2019
SN  - 1869-9510
SN  - 1869-9529
VL  - 10
IS  - 2
SP  - 463
EP  - 486
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - GEN
A1  - Wang, Yongbo
A1  - Herzschuh, Ulrike
A1  - Liu, Xingqi
A1  - Korup, Oliver
A1  - Diekmann, Bernhard
T1  - Reply to Chong Xu’s comment on: Wang, Yongbo; Herzschuh, Ulrike; Liu, Xingqi; Korup, Oliver; Diekmann, Bernhard: A high-resolution sedimentary archive from landslide-dammed Lake Mengda, north-eastern Tibetan Plateau. - Journal of Paleolimnology. -  51 (2014), S. 303 - 312
T2  - Journal of paleolimnolog
Y1  - 2016
U6  - https://doi.org/10.1007/s10933-016-9937-8
SN  - 0921-2728
SN  - 1573-0417
VL  - 57
SP  - 163
EP  - 164
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Wang, Yongbo
A1  - Herzschuh, Ulrike
A1  - Liu, Xingqi
A1  - Korup, Oliver
A1  - Diekmann, Bernhard
T1  - A high-resolution sedimentary archive from landslide-dammed Lake Mengda, north-eastern Tibetan Plateau
JF  - Journal of paleolimnolog
N2  - Lacustrine sediments have been widely used to investigate past climatic and environmental changes on millennial to seasonal time scales. Sedimentary archives of lakes in mountainous regions may also record non-climatic events such as earthquakes. We argue herein that a set of 64 annual laminae couplets reconciles a stratigraphically inconsistent accelerator mass spectrometry (AMS) C-14 chronology in a similar to 4-m-long sediment core from Lake Mengda, in the north-eastern Tibetan Plateau. The laminations suggest the lake was formed by a large landslide, triggered by the 1927 Gulang earthquake (M = 8.0). The lake sediment sequence can be separated into three units based on lithologic, sedimentary, and isotopic characteristics. Starting from the bottom of the sequence, these are: (1) unweathered, coarse, sandy valley-floor deposits or landslide debris that pre-date the lake, (2) landslide-induced, fine-grained soil or reworked landslide debris with a high organic content, and (3) lacustrine sediments with low organic content and laminations. These annual laminations provide a high-resolution record of anthropogenic and environmental changes during the twentieth century, recording enhanced sediment input associated with two phases of construction activities. The high mean sedimentation rates of up to 4.8 mm year(-1) underscore the potential for reconstructing such distinct sediment pulses in remote, forested, and seemingly undisturbed mountain catchments.
KW  - Earthquake
KW  - Landslide
KW  - Natural dam
KW  - Tibetan Plateau
Y1  - 2014
U6  - https://doi.org/10.1007/s10933-012-9666-6
SN  - 0921-2728
SN  - 1573-0417
VL  - 51
IS  - 2
SP  - 303
EP  - 312
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Weidinger, Johannes T.
A1  - Korup, Oliver
A1  - Munack, Henry
A1  - Altenberger, Uwe
A1  - Dunning, Stuart A.
A1  - Tippelt, Gerold
A1  - Lottermoser, Werner
T1  - Giant rockslides from the inside
JF  - Earth & planetary science letters
N2  - The growing body of research on large-scale mass wasting events so far has only scarcely investigated the sedimentology of chaotic deposits from non-volcanic terrestrial landslides such that any overarching and systematic terminological framework remains elusive. Yet recent work has emphasized the need for better understanding the internal structure and composition of rockslide deposits as a means to characterise the mechanics during the final stages of runout and emplacement. We offer a comprehensive overview on the occurrence of rock fragmentation and frictional melt both at different geographic locations, and different sections within large (>10(6) m(3)) rockslide masses. We argue that exposures of pervasively fragmented and interlocked jigsaw-cracked rock masses; basal melange containing rip-up clasts and phantom blocks; micro-breccia; and thin bands of basal frictionite are indispensable clues for identifying deposits from giant rockslides that may remain morphologically inconspicuous otherwise. These sedimentary assemblages are diagnostic tools for distinguishing large rockslide debris from macro and microscopically similar glacial deposits, tectonic fault-zone breccias, and impact breccias, and thus help avoid palaeoclimatic and tectonic misinterpretations, let alone misestimates of the hazard from giant rockslides. Moreover, experimental results from Mossbauer spectroscopy of frictionite samples support visual interpretations of thin sections, and demonstrate that short-lived (<10 s) friction-induced partial melting at temperatures >1500 degrees C in the absence of water occurred at the base of several giant moving rockslides. This finding supports previous theories of dry excess runout accompanied by comminution of rock masses down to gm-scale, and indicates that catastrophic motion of large fragmenting rock masses does not require water as a potential lubricant.
KW  - landslide
KW  - petrography
KW  - frictional melt
KW  - pseudotachylyte
KW  - breccia
KW  - Mossbauer spectroscopy
Y1  - 2014
U6  - https://doi.org/10.1016/j.epsl.2013.12.017
SN  - 0012-821X
SN  - 1385-013X
VL  - 389
SP  - 62
EP  - 73
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Öztürk, Ugur
A1  - Marwan, Norbert
A1  - von Specht, Sebastian
A1  - Korup, Oliver
A1  - Jensen, J.
T1  - A new centennial sea-level record for Antalya, Eastern Mediterranean
JF  - Journal of geophysical research-oceans
N2  - Quantitative estimates of sea-level rise in the Mediterranean Basin become increasingly accurate thanks to detailed satellite monitoring. However, such measuring campaigns cover several years to decades, while longer-term sea-level records are rare for the Mediterranean. We used a data archeological approach to reanalyze monthly mean sea-level data of the Antalya-I (1935–1977) tide gauge to fill this gap. We checked the accuracy and reliability of these data before merging them with the more recent records of the Antalya-II (1985–2009) tide gauge, accounting for an eight-year hiatus. We obtain a composite time series of monthly and annual mean sea levels spanning some 75 years, providing the longest record for the eastern Mediterranean Basin, and thus an essential tool for studying the region's recent sea-level trends. We estimate a relative mean sea-level rise of 2.2 ± 0.5 mm/year between 1935 and 2008, with an annual variability (expressed here as the standard deviation of the residuals, σresiduals = 41.4 mm) above that at the closest tide gauges (e.g., Thessaloniki, Greece, σresiduals = 29.0 mm). Relative sea-level rise accelerated to 6.0 ± 1.5 mm/year at Antalya-II; we attribute roughly half of this rate (~3.6 mm/year) to tectonic crustal motion and anthropogenic land subsidence. Our study highlights the value of data archeology for recovering and integrating historic tide gauge data for long-term sea-level and climate studies.
KW  - sea level
KW  - tide gauge
KW  - data archeology
KW  - Mediterranean Sea
Y1  - 2018
U6  - https://doi.org/10.1029/2018JC013906
SN  - 2169-9275
SN  - 2169-9291
VL  - 123
IS  - 7
SP  - 4503
EP  - 4517
PB  - American Geophysical Union
CY  - Washington
ER  -