@article{WalterHamannLuecketal.2016, author = {Walter, J. and Hamann, G{\"o}ran and L{\"u}ck, Erika and Klingenfuss, C. and Zeitz, Jutta}, title = {Stratigraphy and soil properties of fens: Geophysical case studies from northeastern Germany}, series = {Catena : an interdisciplinary journal of soil science, hydrology, geomorphology focusing on geoecology and landscape evolution}, volume = {142}, journal = {Catena : an interdisciplinary journal of soil science, hydrology, geomorphology focusing on geoecology and landscape evolution}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0341-8162}, doi = {10.1016/j.catena.2016.02.028}, pages = {112 -- 125}, year = {2016}, abstract = {The determination of the total carbon storage of peatlands is of high relevance in the context of climate-change mitigation efforts. This determination relies on data about stratigraphy and peat properties, which are conventionally collected by coring. Ground-penetrating radar (GPR) and electrical resistivity imaging (ERI) can support these point data by providing subsoil information in two-dimensional cross-sections. In this study, GPR and ERI were conducted at two groundwater-fed fen sites located in the temperate zone in north-east Germany. The fens of this region are embedded in low conductive glacial sand and are characterised by thick layers of gyttja, which can be either mineral or organic. The two study sites are representative of this region with respect to stratigraphy (total thickness, peat and gyttja types) and ecological conditions (pH-value, trophic condition). The aim of this study is to assess the suitability of GPR and ERI to detect stratigraphy and peat properties under these characteristic site conditions. Results show that GPR clearly detects the interfaces between (i) Carex and brown-moss peat, (ii) brown-moss peat and organic gyttja, (iii) organic- and mineral gyttja, and (iv) mineral gyttja and the parent material (glacial sand). These layers differ in bulk density and the related organic matter content. ERI, however, does not delineate these layers; rather it delineates regions of varying properties. At our base-rich site, pore fluid conductivity and cation.exchange capacity are the main factors that determine peat electrical conductivity (reverse of resistivity), whereas organic matter and water content are most influential at the more acidic site. Thus the correlation between peat properties and electrical conductivity are driven by site-specific conditions, which are mainly determined by the solute load in the groundwater at fens. When the total organic deposits exceed a thickness of 5 m, the depth of investigation by GPR is limited due to increasing attenuation. This is not a limiting factor for ERI, where the transition from organic deposits to glacial sand is visible at both sites. Due to these specific sensitivities, a combined application of GPR and ERI meets the demand for up-to-date information on carbon storage of peatlands, which is, moreover, very site-specific because of the inherent variety of ecological conditions and stratigraphy between peatlands in general and between fens and bogs in particular. (C) 2016 Elsevier B.V. All rights reserved.}, language = {en} } @phdthesis{Kalbe2016, author = {Kalbe, Johannes}, title = {Stepping stones hominin dispersal out of Africa}, school = {Universit{\"a}t Potsdam}, pages = {122}, year = {2016}, language = {en} } @phdthesis{Simon2016, author = {Simon, Sebastian}, title = {Der Einfluss der Koordination von Spurenelementen in silikatischen und aluminosilikatischen Schmelzen auf Elementverteilungsprozesse in magmatischen Systemen}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-100932}, school = {Universit{\"a}t Potsdam}, pages = {xviii, 138}, year = {2016}, abstract = {Das Wissen um die lokale Struktur von Seltenen Erden Elementen (SEE) in silikatischen und aluminosilikatischen Schmelzen ist von fundamentalem Interesse f{\"u}r die Geochemie der magmatischen Prozesse, speziell wenn es um ein umfassendes Verst{\"a}ndnis der Verteilungsprozesse von SEE in magmatischen Systemen geht. Es ist allgemein akzeptiert, dass die SEE-Verteilungsprozesse von Temperatur, Druck, Sauerstofffugazit{\"a}t (im Fall von polyvalenten Kationen) und der Kristallchemie kontrolliert werden. Allerdings ist wenig {\"u}ber den Einfluss der Schmelzzusammensetzung selbst bekannt. Ziel dieser Arbeit ist, eine Beziehung zwischen der Variation der SEE-Verteilung mit der Schmelzzusammensetzung und der Koordinationschemie dieser SEE in der Schmelze zu schaffen. Dazu wurden Schmelzzusammensetzungen von Prowatke und Klemme (2005), welche eine deutliche {\"A}nderung der Verteilungskoeffizienten zwischen Titanit und Schmelze ausschließlich als Funktion der Schmelzzusammensetzung zeigen, sowie haplogranitische bzw. haplobasaltische Schmelzzusammensetzungen als Vertreter magmatischer Systeme mit La, Gd, Yb und Y dotiert und als Glas synthetisiert. Die Schmelzen variierten systematisch im Aluminiums{\"a}ttigungsindex (ASI), welcher bei den Prowatke und Klemme (2005) Zusammensetzungen einen Bereich von 0.115 bis 0.768, bei den haplogranitischen Zusammensetzungen einen Bereich von 0.935 bis 1.785 und bei den haplobasaltischen Zusammensetzungen einen Bereich von 0.368 bis 1.010 abdeckt. Zus{\"a}tzlich wurden die haplogranitischen Zusammensetzungen mit 4 \% H2O synthetisiert, um den Einfluss von Wasser auf die lokale Umgebung von SEE zu studieren. Um Informationen {\"u}ber die lokalen Struktur von Gd, Yb und Y zu erhalten wurde die R{\"o}ntgenabsorptionsspektroskopie angewendet. Dabei liefert die Untersuchung der Feinstruktur mittels der EXAFS-Spektroskopie (engl. Extended X-Ray Absorption Fine Structure) quantitative Informationen {\"u}ber die lokale Umgebung, w{\"a}hrend RIXS (engl. resonant inelastic X-ray scattering), sowie die daraus extrahierte hoch aufgel{\"o}ste Nahkantenstruktur, XANES (engl. X-ray absorption near edge structure) qualitative Informationen {\"u}ber m{\"o}gliche Koordinations{\"a}nderungen von La, Gd und Yb in den Gl{\"a}sern liefert. Um m{\"o}gliche Unterschiede der lokalen Struktur oberhalb der Glastransformationstemperatur (TG) zur Raumtemperatur zu untersuchen, wurden exemplarisch Hochtemperatur Y-EXAFS Untersuchungen durchgef{\"u}hrt. F{\"u}r die Auswertung der EXAFS-Messungen wurde ein neu eingef{\"u}hrter Histogramm-Fit verwendet, der auch nicht-symmetrische bzw. nichtgaußf{\"o}rmige Paarverteilungsfunktionen beschreiben kann, wie sie bei einem hohen Grad der Polymerisierung bzw. bei hohen Temperaturen auftreten k{\"o}nnen. Die Y-EXAFS-Spektren f{\"u}r die Prowatke und Klemme (2005) Zusammensetzungen zeigen mit Zunahme des ASI, eine Zunahme der Asymmetrie und Breite der Y-O Paarverteilungsfunktion, welche sich in sich in der {\"A}nderung der Koordinationszahl von 6 nach 8 und einer Zunahme des Y-O Abstand um 0.13{\AA} manifestiert. Ein {\"a}hnlicher Trend l{\"a}sst sich auch f{\"u}r die Gd- und Yb-EXAFS-Spektren beobachten. Die hoch aufgel{\"o}sten XANESSpektren f{\"u}r La, Gd und Yb zeigen, dass sich die strukturellen Unterschiede zumindest halb-quantitativ bestimmen lassen. Dies gilt insbesondere f{\"u}r {\"A}nderungen im mittleren Abstand zu den Sauerstoffatomen. Im Vergleich zur EXAFS-Spektroskopie liefert XANES jedoch keine Informationen {\"u}ber die Form und Breite von Paarverteilungsfunktionen. Die Hochtemperatur EXAFS-Untersuchungen von Y zeigen {\"A}nderungen der lokalen Struktur oberhalb der Glas{\"u}bergangstemperatur an, welche sich vordergr{\"u}ndig auf eine thermisch induzierte Erh{\"o}hung des mittleren Y-O Abstandes zur{\"u}ckf{\"u}hren lassen. Allerdings zeigt ein Vergleich der Y-O Abst{\"a}nde f{\"u}r Zusammensetzungen mit einem ASI von 0.115 bzw. 0.755, ermittelt bei Raumtemperatur und TG, dass der im Glas beobachtete strukturelle Unterschied entlang der Zusammensetzungsserie in der Schmelze noch st{\"a}rker ausfallen kann, als bisher f{\"u}r die Gl{\"a}ser angenommen wurde. Die direkte Korrelation der Verteilungsdaten von Prowatke und Klemme (2005) mit den strukturellen {\"A}nderungen der Schmelzen offenbart f{\"u}r Y eine lineare Korrelation, wohingegen Yb und Gd eine nicht lineare Beziehung zeigen. Aufgrund seines Ionenradius und seiner Ladung wird das 6-fach koordinierte SEE in den niedriger polymerisierten Schmelzen bevorzugt durch nicht-br{\"u}ckenbildende Sauerstoffatome koordiniert, um stabile Konfigurationen zu bilden. In den h{\"o}her polymerisierten Schmelzen mit ASI-Werten in der N{\"a}he von 1 ist 6-fache Koordination nicht m{\"o}glich, da fast nur noch br{\"u}ckenbildende Sauerstoffatome zur Verf{\"u}gung stehen. Die {\"U}berbindung von br{\"u}ckenbildenden Sauerstoffatomen um das SEE wird durch Erh{\"o}hung der Koordinationszahl und des mittleren SEE-O Abstandes ausgeglichen. Dies bedeutet eine energetisch g{\"u}nstigere Konfiguration in den st{\"a}rker depolymerisierten Zusammensetzungen, aus welcher die beobachtete Variation des Verteilungskoeffizienten resultiert, welcher sich jedoch f{\"u}r jedes Element stark unterscheidet. F{\"u}r die haplogranitischen und haplobasaltischen Zusammensetzungen wurde mit Zunahme der Polymerisierung auch eine Zunahme der Koordinationszahl und des durchschnittlichen Bindungsabstands, einhergehend mit der Zunahme der Schiefe und der Asymmetrie der Paarverteilungsfunktion, beobachtet. Dies impliziert, dass das jeweilige SEE mit Zunahme der Polymerisierung auch inkompatibler in diesen Zusammensetzungen wird. Weiterhin zeigt die Zugabe von Wasser, dass die Schmelzen depolymerisieren, was in einer symmetrischeren Paarverteilungsfunktion resultiert, wodurch die Kompatibilit{\"a}t wieder zunimmt. Zusammenfassend zeigt sich, dass die Ver{\"a}nderungen der Schmelzzusammensetzungen in einer {\"A}nderung der Polymerisierung der Schmelzen resultieren, die dann einen signifikanten Einfluss auf die lokale Umgebung der SEE hat. Die strukturellen {\"A}nderungen lassen sich direkt mit Verteilungsdaten korrelieren, die Trends unterscheiden sich aber stark zwischen leichten, mittleren und schweren SEE. Allerdings konnte diese Studie zeigen, in welcher Gr{\"o}ßenordnung die {\"A}nderungen liegen m{\"u}ssen, um einen signifikanten Einfluss auf den Verteilungskoeffizenten zu haben. Weiterhin zeigt sich, dass der Einfluss der Schmelzzusammensetzung auf die Verteilung der Spurenelemente mit Zunahme der Polymerisierung steigt und daher nicht vernachl{\"a}ssigt werden darf.}, language = {de} } @phdthesis{Lenz2016, author = {Lenz, Josefine}, title = {Thermokarst dynamics in central-eastern Beringia}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-101364}, school = {Universit{\"a}t Potsdam}, pages = {XII, 128, A-47}, year = {2016}, abstract = {Widespread landscape changes are presently observed in the Arctic and are most likely to accelerate in the future, in particular in permafrost regions which are sensitive to climate warming. To assess current and future developments, it is crucial to understand past environmental dynamics in these landscapes. Causes and interactions of environmental variability can hardly be resolved by instrumental records covering modern time scales. However, long-term environmental variability is recorded in paleoenvironmental archives. Lake sediments are important archives that allow reconstruction of local limnogeological processes as well as past environmental changes driven directly or indirectly by climate dynamics. This study aims at reconstructing Late Quaternary permafrost and thermokarst dynamics in central-eastern Beringia, the terrestrial land mass connecting Eurasia and North America during glacial sea-level low stands. In order to investigate development, processes and influence of thermokarst dynamics, several sediment cores from extant lakes and drained lake basins were analyzed to answer the following research questions: 1. When did permafrost degradation and thermokarst lake development take place and what were enhancing and inhibiting environmental factors? 2. What are the dominant processes during thermokarst lake development and how are they reflected in proxy records? 3. How did, and still do, thermokarst dynamics contribute to the inventory and properties of organic matter in sediments and the carbon cycle? Methods applied in this study are based upon a multi-proxy approach combining sedimentological, geochemical, geochronological, and micropaleontological analyses, as well as analyses of stable isotopes and hydrochemistry of pore-water and ice. Modern field observations of water quality and basin morphometrics complete the environmental investigations. The investigated sediment cores reveal permafrost degradation and thermokarst dynamics on different time scales. The analysis of a sediment core from GG basin on the northern Seward Peninsula (Alaska) shows prevalent terrestrial accumulation of yedoma throughout the Early to Mid Wisconsin with intermediate wet conditions at around 44.5 to 41.5 ka BP. This first wetland development was terminated by the accumulation of a 1-meter-thick airfall tephra most likely originating from the South Killeak Maar eruption at 42 ka BP. A depositional hiatus between 22.5 and 0.23 ka BP may indicate thermokarst lake formation in the surrounding of the site which forms a yedoma upland till today. The thermokarst lake forming GG basin initiated 230 ± 30 cal a BP and drained in Spring 2005 AD. Four years after drainage the lake talik was still unfrozen below 268 cm depth. A permafrost core from Mama Rhonda basin on the northern Seward Peninsula preserved a full lacustrine record including several lake phases. The first lake generation developed at 11.8 cal ka BP during the Lateglacial-Early Holocene transition; its old basin (Grandma Rhonda) is still partially preserved at the southern margin of the study basin. Around 9.0 cal ka BP a shallow and more dynamic thermokarst lake developed with actively eroding shorelines and potentially intermediate shallow water or wetland phases (Mama Rhonda). Mama Rhonda lake drainage at 1.1 cal ka BP was followed by gradual accumulation of terrestrial peat and top-down refreezing of the lake talik. A significant lower organic carbon content was measured in Grandma Rhonda deposits (mean TOC of 2.5 wt\%) than in Mama Rhonda deposits (mean TOC of 7.9 wt\%) highlighting the impact of thermokarst dynamics on biogeochemical cycling in different lake generations by thawing and mobilization of organic carbon into the lake system. Proximal and distal sediment cores from Peatball Lake on the Arctic Coastal Plain of Alaska revealed young thermokarst dynamics since about 1,400 years along a depositional gradient based on reconstructions from shoreline expansion rates and absolute dating results. After its initiation as a remnant pond of a previous drained lake basin, a rapidly deepening lake with increasing oxygenation of the water column is evident from laminated sediments, and higher Fe/Ti and Fe/S ratios in the sediment. The sediment record archived characterizing shifts in depositional regimes and sediment sources from upland deposits and re-deposited sediments from drained thaw lake basins depending on the gradually changing shoreline configuration. These changes are evident from alternating organic inputs into the lake system which highlights the potential for thermokarst lakes to recycle old carbon from degrading permafrost deposits of its catchment. The lake sediment record from Herschel Island in the Yukon (Canada) covers the full Holocene period. After its initiation as a thermokarst lake at 11.7 cal ka BP and intense thermokarst activity until 10.0 cal ka BP, the steady sedimentation was interrupted by a depositional hiatus at 1.6 cal ka BP which likely resulted from lake drainage or allochthonous slumping due to collapsing shore lines. The specific setting of the lake on a push moraine composed of marine deposits is reflected in the sedimentary record. Freshening of the maturing lake is indicated by decreasing electrical conductivity in pore-water. Alternation of marine to freshwater ostracods and foraminifera confirms decreasing salinity as well but also reflects episodical re-deposition of allochthonous marine sediments. Based on permafrost and lacustrine sediment records, this thesis shows examples of the Late Quaternary evolution of typical Arctic permafrost landscapes in central-eastern Beringia and the complex interaction of local disturbance processes, regional environmental dynamics and global climate patterns. This study confirms that thermokarst lakes are important agents of organic matter recycling in complex and continuously changing landscapes.}, language = {en} } @phdthesis{Baese2016, author = {B{\"a}se, Frank}, title = {Interception loss of changing land covers in the humid tropical lowland of Latin America}, school = {Universit{\"a}t Potsdam}, pages = {ix, 85 Seiten}, year = {2016}, abstract = {Das Gebiet der feuchten Tropen ist die am st{\"a}rksten durch den Landnutzungswandel betroffene Region der Erde. Vor allem die Rodung tropischer W{\"a}lder, um Platz f{\"u}r Rinderweiden oder den Anbau von Soja zu schaffen, aber auch seit j{\"u}ngster Zeit die Bem{\"u}hungen um Wiederaufforstungen pr{\"a}gen diesen Landnutzungswandel. Dabei beeinflusst die {\"A}nderung der Vegetationsbedeckung den regionalen Wasserhaushalt auf vielf{\"a}ltige Weise. Betroffen ist unter anderem die Verdunstung von feuchten Oberfl{\"a}chen. Die so genannte Interzeptionsverdunstung bzw. der Interzeptionsverlust tr{\"a}gt erheblich zum Wasserdampfgehalt in der unteren Atmosph{\"a}re und schließlich zur Niederschlagsbildung bei. Ziele dieser Dissertation waren (1) die experimentelle Untersuchung der Interzeptionsverlustunterschiede zwischen einem nat{\"u}rlichen, tropischen Wald und einer Sojaplantage im s{\"u}dlichen Amazonasgebiet, (2) die Modellierung des Interzeptionsverlustes dieser beiden Vegetationsformen im Vergleich zu einem jungen Sekund{\"a}rwald unter dem Aspekt der Unsicherheiten bei der Ableitung notwendiger Modellparameter sowohl im S{\"u}damazonas als auch im Einzugsgebietes des Panamakanals sowie (3) die Wasserhaushaltsanalyse eines vom Landnutzungswandel gepr{\"a}gten Teileinzugsgebietes des Panamakanals in Hinblick auf die Ver{\"a}nderung der Interzeptionsverdunstung durch sich ver{\"a}ndernde Landnutzung und der {\"A}nderung der klimatischen Bedingungen. Die Messung des Interzeptionsverlustes zeigte, dass in der Hauptwachstumsphase vom Soja von dessen Oberfl{\"a}che mehr Wasserverdunstet als von der Oberfl{\"a}che des Waldes. Allerdings ist in der Jahresbilanz der Interzeptionsverlust vom Wald h{\"o}her, da diese Studie nur eine Momentaufnahme zur Zeit der vollen Vegetationsentwicklung des Sojas mit einem Zeitfenster von zwei Monaten widerspiegelt. Durch die geringere ganzj{\"a}hrige Verdunstung von den mit Soja bestandenen Fl{\"a}chen, wird hier der Niederschlag schneller dem Abfluss zugef{\"u}hrt und schell aus der Region ausgetragen. Somit tr{\"a}gt der Landnutzungswandel von Wald zu Soja zu einer mittelfristigen Reduktion des in der Region verf{\"u}gbaren Wassers bei. Die anschließende Modellierung des Interzeptionsverlustes zeigte Einerseits einen starken Einfluss der Datenqualit{\"a}t auf die Plausibilit{\"a}t der Ergebnisse und Andererseits, dass die Sensitivit{\"a}t der einzelnen Parameter zwischen den Untersuchungsgebieten variiert. Eine Schl{\"u}sselrolle nimmt die Wasserspeicherkapazit{\"a}t der Vegetationskrone ein. Dennoch ist die Evaporationsrate die treibende Gr{\"o}ße im Interzeptionsprozess, so dass von ihr die gr{\"o}ßte Unsicherheit ausgeht. Je nach verwendeter Methode zur Ableitung dieses Parameters unterscheiden sich die gewonnenen Parameterwerte erheblich. Die Wirkungsanalyse der Interzeptionsverdunstung auf den Wasserhaushalt im Wirkungsgeflecht der {\"A}nderungen von Temperatur, Niederschlag und Landnutzung im Landschaftsmosaik eines Flusseinzugsgebiets mit Hilfe eines Wasserhaushaltsmodels zeigte den Einfluss der Landnutzungs{\"a}nderung auf die Abflussbildung mittels verschiedener Landnutzungsszenarien. Die Ergebnisse belegen, dass die Landnutzungs{\"a}nderung im Gebiet nur einen geringen Einfluss auf den Jahresabfluss hat. St{\"a}rker scheint sich der gemessene Temperaturanstieg auf die Verdunstung auszuwirken. Der mit einer h{\"o}heren Temperatur einhergehende Anstieg der Transpiration und Interzeptionsverdunstung gleicht die gemessene Zunahme des Gebietsniederschlages aus, sodass keine signifikanten {\"A}nderungen im Jahresabfluss nachgewiesen werden konnten. Die Ergebnisse der drei Studien verdeutlichen den Einfluss der Landnutzung auf die Interzeptionsverdunstung. Allerdings veranschaulichten die Resultate der Wasserhaushalts-modellierung, wie sehr dieser Einfluss durch die Ver{\"a}nderung der {\"a}ußeren Rahmenbedingungen, vor allem durch den Anstieg der Temperatur, {\"u}berpr{\"a}gt werden kann. Dies belegt, dass eine einfache {\"U}bertragung der Ergebnisse zwischen den Untersuchungsgebiet nicht m{\"o}glich ist. Somit bleibt die experimentelle Erhebung von Vegetationsparametern sowie des Interzeptionsverlustes an den jeweils zu untersuchenden Standort f{\"u}r die Anwendung von Modellen unerl{\"a}sslich.}, language = {en} } @phdthesis{Draeger2016, author = {Dr{\"a}ger, Nadine}, title = {Holocene climate and environmental variability in NE Germany inferred from annually laminated lake sediments}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-103037}, school = {Universit{\"a}t Potsdam}, pages = {xv, 144 Seiten}, year = {2016}, abstract = {Understanding the role of natural climate variability under the pressure of human induced changes of climate and landscapes, is crucial to improve future projections and adaption strategies. This doctoral thesis aims to reconstruct Holocene climate and environmental changes in NE Germany based on annually laminated lake sediments. The work contributes to the ICLEA project (Integrated CLimate and Landscape Evolution Analyses). ICLEA intends to compare multiple high-resolution proxy records with independent chronologies from the N central European lowlands, in order to disentangle the impact of climate change and human land use on landscape development during the Lateglacial and Holocene. In this respect, two study sites in NE Germany are investigated in this doctoral project, Lake Tiefer See and palaeolake Wukenfurche. While both sediment records are studied with a combination of high-resolution sediment microfacies and geochemical analyses (e.g. µ-XRF, carbon geochemistry and stable isotopes), detailed proxy understanding mainly focused on the continuous 7.7 m long sediment core from Lake Tiefer See covering the last ~6000 years. Three main objectives are pursued at Lake Tiefer See: (1) to perform a reliable and independent chronology, (2) to establish microfacies and geochemical proxies as indicators for climate and environmental changes, and (3) to trace the effects of climate variability and human activity on sediment deposition. Addressing the first aim, a reliable chronology of Lake Tiefer See is compiled by using a multiple-dating concept. Varve counting and tephra findings form the chronological framework for the last ~6000 years. The good agreement with independent radiocarbon dates of terrestrial plant remains verifies the robustness of the age model. The resulting reliable and independent chronology of Lake Tiefer See and, additionally, the identification of nine tephras provide a valuable base for detailed comparison and synchronization of the Lake Tiefer See data set with other climate records. The sediment profile of Lake Tiefer See exhibits striking alternations between well-varved and non-varved sediment intervals. The combination of microfacies, geochemical and microfossil (i.e. Cladocera and diatom) analyses indicates that these changes of varve preservation are caused by variations of lake circulation in Lake Tiefer See. An exception is the well-varved sediment deposited since AD 1924, which is mainly influenced by human-induced lake eutrophication. Well-varved intervals before the 20th century are considered to reflect phases of reduced lake circulation and, consequently, stronger anoxic conditions. Instead, non-varved intervals indicate increased lake circulation in Lake Tiefer See, leading to more oxygenated conditions at the lake ground. Furthermore, lake circulation is not only influencing sediment deposition, but also geochemical processes in the lake. As, for example, the proxy meaning of δ13COM varies in time in response to changes of the oxygen regime in the lake hypolinion. During reduced lake circulation and stronger anoxic conditions δ13COM is influenced by microbial carbon cycling. In contrast, organic matter degradation controls δ13COM during phases of intensified lake circulation and more oxygenated conditions. The varve preservation indicates an increasing trend of lake circulation at Lake Tiefer See after ~4000 cal a BP. This trend is superimposed by decadal to centennial scale variability of lake circulation intensity. Comparison to other records in Central Europe suggests that the long-term trend is probably related to gradual changes in Northern Hemisphere orbital forcing, which induced colder and windier conditions in Central Europe and, therefore, reinforced lake circulation. Decadal to centennial scale periods of increased lake circulation coincide with settlement phases at Lake Tiefer See, as inferred from pollen data of the same sediment record. Deforestation reduced the wind shelter of the lake, which probably increased the sensitivity of lake circulation to wind stress. However, results of this thesis also suggest that several of these phases of increased lake circulation are additionally reinforced by climate changes. A first indication is provided by the comparison to the Baltic Sea record, which shows striking correspondence between major non-varved intervals at Lake Tiefer See and bioturbated sediments in the Baltic Sea. Furthermore, a preliminary comparison to the ICLEA study site Lake Czechowskie (N central Poland) shows a coincidence of at least three phases of increased lake circulation in both lakes, which concur with periods of known climate changes (2.8 ka event, 'Migration Period' and 'Little Ice Age'). These results suggest an additional over-regional climate forcing also on short term increased of lake circulation in Lake Tiefer See. In summary, the results of this thesis suggest that lake circulation at Lake Tiefer See is driven by a combination of long-term and short-term climate changes as well as of anthropogenic deforestation phases. Furthermore, the lake circulation drives geochemical cycles in the lake affecting the meaning of proxy data. Therefore, the work presented here expands the knowledge of climate and environmental variability in NE Germany. Furthermore, the integration of the Lake Tiefer See multi-proxy record in a regional comparison with another ICLEA side, Lake Czechowskie, enabled to better decipher climate changes and human impact on the lake system. These first results suggest a huge potential for further detailed regional comparisons to better understand palaeoclimate dynamics in N central Europe.}, language = {en} } @phdthesis{Chen2016, author = {Chen, Kejie}, title = {Real-time GNSS for fast seismic source inversion and tsunami early warning}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-93174}, school = {Universit{\"a}t Potsdam}, pages = {xii, 81}, year = {2016}, abstract = {Over the past decades, rapid and constant advances have motivated GNSS technology to approach the ability to monitor transient ground motions with mm to cm accuracy in real-time. As a result, the potential of using real-time GNSS for natural hazards prediction and early warning has been exploited intensively in recent years, e.g., landslides and volcanic eruptions monitoring. Of particular note, compared with traditional seismic instruments, GNSS does not saturate or tilt in terms of co-seismic displacement retrieving, which makes it especially valuable for earthquake and earthquake induced tsunami early warning. In this thesis, we focus on the application of real-time GNSS to fast seismic source inversion and tsunami early warning. Firstly, we present a new approach to get precise co-seismic displacements using cost effective single-frequency receivers. As is well known, with regard to high precision positioning, the main obstacle for single-frequency GPS receiver is ionospheric delay. Considering that over a few minutes, the change of ionospheric delay is almost linear, we constructed a linear model for each satellite to predict ionospheric delay. The effectiveness of this method has been validated by an out-door experiment and 2011 Tohoku event, which confirms feasibility of using dense GPS networks for geo-hazard early warning at an affordable cost. Secondly, we extended temporal point positioning from GPS-only to GPS/GLONASS and assessed the potential benefits of multi-GNSS for co-seismic displacement determination. Out-door experiments reveal that when observations are conducted in an adversary environment, adding a couple of GLONASS satellites could provide more reliable results. The case study of 2015 Illapel Mw 8.3 earthquake shows that the biases between co-seismic displacements derived from GPS-only and GPS/GLONASS vary from station to station, and could be up to 2 cm in horizontal direction and almost 3 cm in vertical direction. Furthermore, slips inverted from GPS/GLONASS co-seismic displacements using a layered crust structure on a curved plane are shallower and larger for the Illapel event. Thirdly, we tested different inversion tools and discussed the uncertainties of using real-time GNSS for tsunami early warning. To be exact, centroid moment tensor inversion, uniform slip inversion using a single Okada fault and distributed slip inversion in layered crust on a curved plane were conducted using co-seismic displacements recorded during 2014 Pisagua earthquake. While the inversion results give similar magnitude and the rupture center, there are significant differences in depth, strike, dip and rake angles, which lead to different tsunami propagation scenarios. Even though, resulting tsunami forecasting along the Chilean coast is close to each other for all three models. Finally, based on the fact that the positioning performance of BDS is now equivalent to GPS in Asia-Pacific area and Manila subduction zone has been identified as a zone of potential tsunami hazard, we suggested a conceptual BDS/GPS network for tsunami early warning in South China Sea. Numerical simulations with two earthquakes (Mw 8.0 and Mw 7.5) and induced tsunamis demonstrate the viability of this network. In addition, the advantage of BDS/GPS over a single GNSS system by source inversion grows with decreasing earthquake magnitudes.}, language = {en} } @article{SalamatZareHolschneideretal.2016, author = {Salamat, Mona and Zare, Mehdi and Holschneider, Matthias and Z{\"o}ller, Gert}, title = {Calculation of Confidence Intervals for the Maximum Magnitude of Earthquakes in Different Seismotectonic Zones of Iran}, series = {Pure and applied geophysics}, volume = {174}, journal = {Pure and applied geophysics}, publisher = {Springer}, address = {Basel}, issn = {0033-4553}, doi = {10.1007/s00024-016-1418-5}, pages = {763 -- 777}, year = {2016}, abstract = {The problem of estimating the maximum possible earthquake magnitude m(max) has attracted growing attention in recent years. Due to sparse data, the role of uncertainties becomes crucial. In this work, we determine the uncertainties related to the maximum magnitude in terms of confidence intervals. Using an earthquake catalog of Iran, m(max) is estimated for different predefined levels of confidence in six seismotectonic zones. Assuming the doubly truncated Gutenberg-Richter distribution as a statistical model for earthquake magnitudes, confidence intervals for the maximum possible magnitude of earthquakes are calculated in each zone. While the lower limit of the confidence interval is the magnitude of the maximum observed event, the upper limit is calculated from the catalog and the statistical model. For this aim, we use the original catalog which no declustering methods applied on as well as a declustered version of the catalog. Based on the study by Holschneider et al. (Bull Seismol Soc Am 101(4): 1649-1659, 2011), the confidence interval for m(max) is frequently unbounded, especially if high levels of confidence are required. In this case, no information is gained from the data. Therefore, we elaborate for which settings finite confidence levels are obtained. In this work, Iran is divided into six seismotectonic zones, namely Alborz, Azerbaijan, Zagros, Makran, Kopet Dagh, Central Iran. Although calculations of the confidence interval in Central Iran and Zagros seismotectonic zones are relatively acceptable for meaningful levels of confidence, results in Kopet Dagh, Alborz, Azerbaijan and Makran are not that much promising. The results indicate that estimating mmax from an earthquake catalog for reasonable levels of confidence alone is almost impossible.}, language = {en} } @article{BudkeKuckuckWienecke2016, author = {Budke, Alexandra and Kuckuck, Miriam and Wienecke, Maik}, title = {Realisierungen der Politischen Bildung im Geographieunterricht}, series = {Politische Bildung im Geographieunterricht}, journal = {Politische Bildung im Geographieunterricht}, editor = {Budke, Alexandra and Kuckuck, Miriam}, publisher = {Steiner}, address = {Stuttgart}, isbn = {978-3-515-11325-0}, pages = {155 -- 165}, year = {2016}, language = {de} } @misc{XiongStolleLuehretal.2016, author = {Xiong, Chao and Stolle, Claudia and L{\"u}hr, Hermann and Park, Jaeheung and Fejer, Bela G. and Kervalishvili, Guram N.}, title = {Scale analysis of equatorial plasma irregularities derived from Swarm constellation}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1112}, issn = {1866-8372}, doi = {10.25932/publishup-43184}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-431842}, pages = {14}, year = {2016}, abstract = {In this study, we investigated the scale sizes of equatorial plasma irregularities (EPIs) using measurements from the Swarm satellites during its early mission and final constellation phases. We found that with longitudinal separation between Swarm satellites larger than 0.4°, no significant correlation was found any more. This result suggests that EPI structures include plasma density scale sizes less than 44 km in the zonal direction. During the Swarm earlier mission phase, clearly better EPI correlations are obtained in the northern hemisphere, implying more fragmented irregularities in the southern hemisphere where the ambient magnetic field is low. The previously reported inverted-C shell structure of EPIs is generally confirmed by the Swarm observations in the northern hemisphere, but with various tilt angles. From the Swarm spacecrafts with zonal separations of about 150 km, we conclude that larger zonal scale sizes of irregularities exist during the early evening hours (around 1900 LT).}, language = {en} } @article{HundechaSunyerLawrenceetal.2016, author = {Hundecha, Yeshewatesfa and Sunyer, Maria A. and Lawrence, Deborah and Madsen, Henrik and Willems, Patrick and B{\"u}rger, Gerd and Kriauciuniene, Jurate and Loukas, Athanasios and Martinkova, Marta and Osuch, Marzena and Vasiliades, Lampros and von Christierson, Birgitte and Vormoor, Klaus Josef and Yuecel, Ismail}, title = {Inter-comparison of statistical downscaling methods for projection of extreme flow indices across Europe}, series = {Journal of hydrology}, volume = {541}, journal = {Journal of hydrology}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0022-1694}, doi = {10.1016/j.jhydrol.2016.08.033}, pages = {1273 -- 1286}, year = {2016}, abstract = {The effect of methods of statistical downscaling of daily precipitation on changes in extreme flow indices under a plausible future climate change scenario was investigated in 11 catchments selected from 9 countries in different parts of Europe. The catchments vary from 67 to 6171 km(2) in size and cover different climate zones. 15 regional climate model outputs and 8 different statistical downscaling methods, which are broadly categorized as change factor and bias correction based methods, were used for the comparative analyses. Different hydrological models were implemented in different catchments to simulate daily runoff. A set of flood indices were derived from daily flows and their changes have been evaluated by comparing their values derived from simulations corresponding to the current and future climate. Most of the implemented downscaling methods project an increase in the extreme flow indices in most of the catchments. The catchments where the extremes are expected to increase have a rainfall dominated flood regime. In these catchments, the downscaling methods also project an increase in the extreme precipitation in the seasons when the extreme flows occur. In catchments where the flooding is mainly caused by spring/summer snowmelt, the downscaling methods project a decrease in the extreme flows in three of the four catchments considered. A major portion of the variability in the projected changes in the extreme flow indices is attributable to the variability of the climate model ensemble, although the statistical downscaling methods contribute 35-60\% of the total variance. (C) 2016 Elsevier B.V. All rights reserved.}, language = {en} } @article{VormoorLawrenceSchlichtingetal.2016, author = {Vormoor, Klaus Josef and Lawrence, Deborah and Schlichting, Lena and Wilson, Donna and Wong, Wai Kwok}, title = {Evidence for changes in the magnitude and frequency of observed rainfall vs. snowmelt driven floods in Norway}, series = {Journal of hydrology}, volume = {538}, journal = {Journal of hydrology}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0022-1694}, doi = {10.1016/j.jhydrol.2016.03.066}, pages = {33 -- 48}, year = {2016}, abstract = {There is increasing evidence for recent changes in the intensity and frequency of heavy precipitation and in the number of days with snow cover in many parts of Norway. The question arises as to whether these changes are also discernable with respect to their impacts on the magnitude and frequency of flooding and on the processes producing high flows. In this study, we tested up to 211 catchments for trends in peak flow discharge series by applying the Mann-Kendall test and Poisson regression for three different time periods (1962-2012, 1972-2012, 1982-2012). Field-significance was tested using a bootstrap approach. Over threshold discharge events were classified into rainfall vs. snowmelt dominated floods, based on a simple water balance approach utilizing a nationwide 1 x 1 km(2) gridded data set with daily observed rainfall and simulated snowmelt data. Results suggest that trends in flood frequency are more pronounced than trends in flood magnitude and are more spatially consistent with observed changes in the hydrometeorological drivers. Increasing flood frequencies in southern and western Norway are mainly due to positive trends in the frequency of rainfall dominated events, while decreasing flood frequencies in northern Norway are mainly the result of negative trends in the frequency of snowmelt dominated floods. Negative trends in flood magnitude are found more often than positive trends, and the regional patterns of significant trends reflect differences in the flood generating processes (FGPs). The results illustrate the benefit of distinguishing FGPs rather than simply applying seasonal analyses. The results further suggest that rainfall has generally gained an increasing importance for the generation of floods in Norway, while the role of snowmelt has been decreasing and the timing of snowmelt dominated floods has become earlier. (C) 2016 Elsevier B.V. All rights reserved.}, language = {en} } @article{AbdrakhmatovWalkerCampbelletal.2016, author = {Abdrakhmatov, Kanatbek E. and Walker, R. T. and Campbell, G. E. and Carr, A. S. and Elliott, A. and Hillemann, Christian and Hollingsworth, J. and Landgraf, Angela and Mackenzie, D. and Mukambayev, A. and Rizza, M. and Sloan, R. A.}, title = {Multisegment rupture in the 11 July 1889 Chilik earthquake (M-w 8.0-8.3), Kazakh Tien Shan, interpreted from remote sensing, field survey, and paleoseismic trenching}, series = {Journal of geophysical research : Solid earth}, volume = {121}, journal = {Journal of geophysical research : Solid earth}, publisher = {American Geophysical Union}, address = {Washington}, issn = {2169-9313}, doi = {10.1002/2015JB012763}, pages = {4615 -- 4640}, year = {2016}, abstract = {The 11 July 1889 Chilik earthquake (M-w 8.0-8.3) forms part of a remarkable sequence of large earthquakes in the late nineteenth and early twentieth centuries in the northern Tien Shan. Despite its importance, the source of the 1889 earthquake remains unknown, though the macroseismic epicenter is sited in the Chilik valley, similar to 100 km southeast of Almaty, Kazakhstan (similar to 2 million population). Several short fault segments that have been inferred to have ruptured in 1889 are too short on their own to account for the estimated magnitude. In this paper we perform detailed surveying and trenching of the similar to 30 km long Saty fault, one of the previously inferred sources, and find that it was formed in a single earthquake within the last 700 years, involving surface slip of up to 10 m. The scarp-forming event, likely to be the 1889 earthquake, was the only surface-rupturing event for at least 5000 years and potentially for much longer. From satellite imagery we extend the mapped length of fresh scarps within the 1889 epicentral zone to a total of similar to 175 km, which we also suggest as candidate ruptures from the 1889 earthquake. The 175 km of rupture involves conjugate oblique left-lateral and right-lateral slip on three separate faults, with step overs of several kilometers between them. All three faults were essentially invisible in the Holocene geomorphology prior to the last slip. The recurrence interval between large earthquakes on any of these faults, and presumably on other faults of the Tien Shan, may be longer than the timescale over which the landscape is reset, providing a challenge for delineating sources of future hazard.}, language = {en} } @phdthesis{Wolter2016, author = {Wolter, Juliane}, title = {Mid- to Late Holocene environmental dynamics on the Yukon Coastal Plain and Herschel Island (Canada) - envidence from polygonal peatlands and lake sediment}, school = {Universit{\"a}t Potsdam}, pages = {176}, year = {2016}, language = {en} } @article{KuehnAltmannsbergerHens2016, author = {K{\"u}hn, Michael and Altmannsberger, Charlotte and Hens, Carmen}, title = {Waiweras WarmwasserreservoirWelche Aussagekraft haben Modelle?}, series = {Grundwasser : Zeitschrift der Fachsektion Hydrogeologie in der Deutschen Gesellschaft f{\~A}¼r Geowissenschaften (FH-DGG)}, volume = {21}, journal = {Grundwasser : Zeitschrift der Fachsektion Hydrogeologie in der Deutschen Gesellschaft f{\~A}¼r Geowissenschaften (FH-DGG)}, publisher = {Springer}, address = {Heidelberg}, issn = {1430-483X}, doi = {10.1007/s00767-016-0323-2}, pages = {107 -- 117}, year = {2016}, abstract = {The warm water geothermal reservoir below the village of Waiwera in New Zealand has been known by the native Maori for centuries. Development by the European immigrants began in 1863. Until the year 1969, the warm water flowing from all drilled wells was artesian. Due to overproduction, water up to 50 A degrees C now needs to be pumped to surface. Further, between 1975 and 1976, all warm water seeps on the beach of Waiwera ran dry. Within the context of sustainable water management, hydrogeological models must be developed as part of a management plan. Approaches of varying complexity have been set-up and applied since the 1980s. However, none of the models directly provide all results required for optimal water management. Answers are given simply to parts of the questions, nonetheless improving resource management of the geothermal reservoir.}, language = {de} } @article{TillnerLangerKempkaetal.2016, author = {Tillner, Elena and Langer, Maria and Kempka, Thomas and K{\"u}hn, Michael}, title = {Fault damage zone volume and initial salinity distribution determine intensity of shallow aquifer salinisation in subsurface storage}, series = {Hydrology and earth system sciences : HESS}, volume = {20}, journal = {Hydrology and earth system sciences : HESS}, publisher = {Copernicus}, address = {G{\"o}ttingen}, issn = {1027-5606}, doi = {10.5194/hess-20-1049-2016}, pages = {1049 -- 1067}, year = {2016}, abstract = {Injection of fluids into deep saline aquifers causes a pore pressure increase in the storage formation, and thus displacement of resident brine. Via hydraulically conductive faults, brine may migrate upwards into shallower aquifers and lead to unwanted salinisation of potable groundwater resources. In the present study, we investigated different scenarios for a potential storage site in the Northeast German Basin using a three-dimensional (3-D) regional-scale model that includes four major fault zones. The focus was on assessing the impact of fault length and the effect of a secondary reservoir above the storage formation, as well as model boundary conditions and initial salinity distribution on the potential salinisation of shallow groundwater resources. We employed numerical simulations of brine injection as a representative fluid. Our simulation results demonstrate that the lateral model boundary settings and the effective fault damage zone volume have the greatest influence on pressure build-up and development within the reservoir, and thus intensity and duration of fluid flow through the faults. Higher vertical pressure gradients for short fault segments or a small effective fault damage zone volume result in the highest salinisation potential due to a larger vertical fault height affected by fluid displacement. Consequently, it has a strong impact on the degree of shallow aquifer salinisation, whether a gradient in salinity exists or the saltwater-freshwater interface lies below the fluid displacement depth in the faults. A small effective fault damage zone volume or low fault permeability further extend the duration of fluid flow, which can persist for several tens to hundreds of years, if the reservoir is laterally confined. Laterally open reservoir boundaries, large effective fault damage zone volumes and intermediate reservoirs significantly reduce vertical brine migration and the potential of freshwater salinisation because the origin depth of displaced brine is located only a few decametres below the shallow aquifer in maximum. The present study demonstrates that the existence of hydraulically conductive faults is not necessarily an exclusion criterion for potential injection sites, because salinisation of shallower aquifers strongly depends on initial salinity distribution, location of hydraulically conductive faults and their effective damage zone volumes as well as geological boundary conditions.}, language = {en} } @article{CohenCampisanoArrowsmithetal.2016, author = {Cohen, Andrew and Campisano, C. and Arrowsmith, J. Ram{\´o}n and Asrat, Asfawossen and Behrensmeyer, A. K. and Deino, A. and Feibel, C. and Hill, A. and Johnson, R. and Kingston, J. and Lamb, Henry F. and Lowenstein, T. and Noren, A. and Olago, D. and Owen, R. B. and Potts, R. and Reed, Kate and Renaut, R. and Sch{\"a}bitz, Frank and Tiercelin, J. -J. and Trauth, Martin H. and Wynn, J. and Ivory, S. and Brady, K. and Rodysill, J. and Githiri, J. and Russell, J. and F{\"o}rster, Verena and Dommain, Ren{\´e} and Rucina, S. and Deocampo, D. and Russell, J. and Billingsley, A. and Beck, C. and Dorenbeck, G. and Dullo, L. and Feary, D. and Garello, D. and Gromig, R. and Johnson, T. and Junginger, A. and Karanja, M. and Kimburi, E. and Mbuthia, A. and McCartney, T. and McNulty, E. and Muiruri, V. and Nambiro, E. and Negash, E. W. and Njagi, D. and Wilson, J. N. and Rabideaux, N. and Raub, T. and Sier, M. J. and Smith, P. and Urban, J. and Warren, M. and Yadeta, M. and Yost, C. and Zinaye, B.}, title = {The Hominin Sites and Paleolakes Drilling Project: inferring the environmental context of human evolution from eastern African rift lake deposits}, series = {Scientific Drilling}, volume = {21}, journal = {Scientific Drilling}, publisher = {Copernicus}, address = {G{\"o}ttingen}, issn = {1816-8957}, doi = {10.5194/sd-21-1-2016}, pages = {1 -- 16}, year = {2016}, abstract = {The role that climate and environmental history may have played in influencing human evolution has been the focus of considerable interest and controversy among paleoanthropologists for decades. Prior attempts to understand the environmental history side of this equation have centered around the study of outcrop sediments and fossils adjacent to where fossil hominins (ancestors or close relatives of modern humans) are found, or from the study of deep sea drill cores. However, outcrop sediments are often highly weathered and thus are unsuitable for some types of paleoclimatic records, and deep sea core records come from long distances away from the actual fossil and stone tool remains. The Hominin Sites and Paleolakes Drilling Project (HSPDP) was developed to address these issues. The project has focused its efforts on the eastern African Rift Valley, where much of the evidence for early hominins has been recovered. We have collected about 2 km of sediment drill core from six basins in Kenya and Ethiopia, in lake deposits immediately adjacent to important fossil hominin and archaeological sites. Collectively these cores cover in time many of the key transitions and critical intervals in human evolutionary history over the last 4 Ma, such as the earliest stone tools, the origin of our own genus Homo, and the earliest anatomically modern Homo sapiens. Here we document the initial field, physical property, and core description results of the 2012-2014 HSPDP coring campaign.}, language = {en} } @phdthesis{Rieckh2016, author = {Rieckh, Helene}, title = {Hydropedological analysis of erosion-affected soils in a hummocky ground-moraine landscape - interactions of water flow, dissolved carbon and particle transport, grop growth, and pedogenesis}, school = {Universit{\"a}t Potsdam}, pages = {154}, year = {2016}, language = {en} } @article{BaesGeryaSobolev2016, author = {Baes, Marzieh and Gerya, Taras V. and Sobolev, Stephan Vladimir}, title = {3-D thermo-mechanical modeling of plume-induced subduction initiation}, series = {Earth \& planetary science letters}, volume = {453}, journal = {Earth \& planetary science letters}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0012-821X}, doi = {10.1016/j.epsl.2016.08.023}, pages = {193 -- 203}, year = {2016}, abstract = {Here, we study the 3-D subduction initiation process induced by the interaction between a hot thermochemical mantle plume and oceanic lithosphere using thermo-mechanical viscoplastic finite difference marker-in-cell models. Our numerical modeling results show that self-sustaining subduction is induced by plume-lithosphere interaction when the plume is sufficiently buoyant, the oceanic lithosphere is sufficiently old and the plate is weak enough to allow the buoyant plume to. pass through it. Subduction initiation occurs following penetration of the lithosphere by the hot plume and the downward displacement of broken, nearly circular segments of lithosphere (proto-slabs) as a result of partially molten plume rocks overriding the proto-slabs. Our experiments show four different deformation regimes in response to plume-lithosphere interaction: a) self-sustaining subduction initiation, in which subduction becomes self-sustaining; b) frozen subduction initiation, in which subduction stops at shallow depths; c) slab break-off, in which the subducting circular slab breaks off soon after formation; and d) plume underplating, in which the plume does not pass through the lithosphere and instead spreads beneath it (i.e., failed subduction initiation). These regimes depend on several parameters, such as the size, composition, and temperature of the plume, the brittle/plastic strength and age of the oceanic lithosphere, and the presence/absence of lithospheric heterogeneities. The results show that subduction initiates and becomes self-sustaining when the lithosphere is older than 10 Myr and the non dimensional ratio of the plume buoyancy force and lithospheric strength above the plume is higher than approximately 2. The outcomes of our numerical experiments are applicable for subduction initiation in the modern and Precambrian Earth and for the origin of plume-related corona structures on Venus. (C) 2016 Elsevier B.V. All rights reserved.}, language = {en} } @phdthesis{Roers2016, author = {Roers, Michael}, title = {Methoden zur Dynamisierung von Klimafolgenanalysen im Elbegebiet}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-98844}, school = {Universit{\"a}t Potsdam}, pages = {xiii, 141}, year = {2016}, abstract = {Die Elbe und ihr Einzugsgebiet sind vom Klimawandel betroffen. Um die Wirkkette von projizierten Klimaver{\"a}nderungen auf den Wasserhaushalt und die daraus resultierenden N{\"a}hrstoffeintr{\"a}ge und -frachten f{\"u}r große Einzugsgebiete wie das der Elbe zu analysieren, k{\"o}nnen integrierte Umweltmodellsysteme eingesetzt werden. Fallstudien, die mit diesen Modellsystemen ad hoc durchgef{\"u}hrt werden, repr{\"a}sentieren den Istzustand von Modellentwicklungen und -unsicherheiten und sind damit statisch. Diese Arbeit beschreibt den Einstieg in die Dynamisierung von Klimafolgenanalysen im Elbegebiet. Dies umfasst zum einen eine Plausibilit{\"a}tspr{\"u}fung von Auswirkungsrechnungen, die mit Szenarien des statistischen Szenariengenerators STARS durchgef{\"u}hrt wurden, durch den Vergleich mit den Auswirkungen neuerer Klimaszenarien aus dem ISI-MIP Projekt, die dem letzten Stand der Klimamodellierung entsprechen. Hierf{\"u}r wird ein integriertes Modellsystem mit "eingefrorenem Entwicklungsstand" verwendet. Die Klimawirkungsmodelle bleiben dabei unver{\"a}ndert. Zum anderen wird ein Bestandteil des integrierten Modellsystems - das {\"o}kohydrologische Modell SWIM - zu einer "live"-Version weiterentwickelt. Diese wird durch punktuelle Testung an langj{\"a}hrigen Versuchsreihen eines Lysimeterstandorts sowie an aktuellen Abflussreihen validiert und verbessert. Folgende Forschungsfragen werden bearbeitet: (i) Welche Effekte haben unterschiedliche Klimaszenarien auf den Wasserhaushalt im Elbegebiet und ist eine Neubewertung der Auswirkung des Klimawandels auf den Wasserhaushalt notwendig?, (ii) Was sind die Auswirkungen des Klimawandels auf die N{\"a}hrstoffeintr{\"a}ge und -frachten im Elbegebiet sowie die Wirksamkeit von Maßnahmen zur Reduktion der N{\"a}hrstoffeintr{\"a}ge?, (iii) Ist unter der Nutzung (selbst einer sehr geringen Anzahl) verf{\"u}gbarer tagesaktueller Witterungsdaten in einem stark heterogenen Einzugsgebiet eine valide Ansprache der aktuellen {\"o}kohydrologischen Situation des Elbeeinzugsgebiets m{\"o}glich? Die aktuellen Szenarien best{\"a}tigen die Richtung, jedoch nicht das Ausmaß der Klimafolgen: Die R{\"u}ckg{\"a}nge des mittleren j{\"a}hrlichen Gesamtabflusses und der monatlichen Abfl{\"u}sse an den Pegeln bis Mitte des Jahrhunderts betragen f{\"u}r das STARS-Szenario ca. 30 \%. Die R{\"u}ckg{\"a}nge bei den auf dem ISI-MIP-Szenario basierenden Modellstudien liegen hingegen nur bei ca. 10 \%. Hauptursachen f{\"u}r diese Divergenz sind die Unterschiede in den Niederschlagsprojektionen sowie die Unterschiede in der jahreszeitlichen Verteilung der Erw{\"a}rmung. Im STARS-Szenario gehen methodisch bedingt die Niederschl{\"a}ge zur{\"u}ck und der Winter erw{\"a}rmt sich st{\"a}rker als der Sommer. In dem ISI-MIP-Szenario bleiben die Niederschl{\"a}ge nahezu stabil und die Erw{\"a}rmung im Sommer und Winter unterscheidet sich nur geringf{\"u}gig. Generell nehmen die N{\"a}hrstoffeintr{\"a}ge und -frachten mit den Abfl{\"u}ssen in beiden Szenarien unterproportional ab, wobei die Frachten jeweils st{\"a}rker als die Eintr{\"a}ge zur{\"u}ckgehen. Die konkreten Effekte der Abfluss{\"a}nderungen sind gering und liegen im einstelligen Prozentbereich. Gleiches gilt f{\"u}r die Unterschiede zwischen den Szenarien. Der Effekt von zwei ausgew{\"a}hlten Maßnahmen zur Reduktion der N{\"a}hrstoffeintr{\"a}ge und -frachten unterscheidet sich bei verschiedenen Abflussverh{\"a}ltnissen, repr{\"a}sentiert durch unterschiedliche Klimaszenarien in unterschiedlich feuchter Auspr{\"a}gung, ebenfalls nur geringf{\"u}gig. Die Beantwortung der ersten beiden Forschungsfragen zeigt, dass die Aktualisierung von Klimaszenarien in einem ansonsten "eingefrorenen" Verbund von {\"o}kohydrologischen Daten und Modellen eine wichtige Pr{\"u}foption f{\"u}r die Plausibilisierung von Klimafolgenanalysen darstellt. Sie bildet die methodische Grundlage f{\"u}r die Schlussfolgerung, dass bei der Wassermenge eine Neubewertung der Klimafolgen notwendig ist, w{\"a}hrend dies bei den N{\"a}hrstoffeintr{\"a}gen und -frachten nicht der Fall ist. Die zur Beantwortung der dritten Forschungsfrage mit SWIM-live durchgef{\"u}hrten Validierungsstudien ergeben Diskrepanzen am Lysimeterstandort und bei den Abfl{\"u}ssen aus den Teilgebieten Saale und Spree. Sie lassen sich zum Teil mit der notwendigen Interpolationsweite der Witterungsdaten und dem Einfluss von Wasserbewirtschaftungsmaßnahmen erkl{\"a}ren. Insgesamt zeigen die Validierungsergebnisse, dass schon die Pilotversion von SWIM-live f{\"u}r eine {\"o}kohydrologische Ansprache des Gebietswasserhaushaltes im Elbeeinzugsgebiet genutzt werden kann. SWIM-live erm{\"o}glicht eine unmittelbare Betrachtung und Beurteilung simulierter Daten. Dadurch werden Unsicherheiten bei der Modellierung direkt offengelegt und k{\"o}nnen infolge dessen reduziert werden. Zum einen f{\"u}hrte die Verdichtung der meteorologischen Eingangsdaten durch die Verwendung von nun ca. 700 anstatt 19 Klima- bzw. Niederschlagstationen zu einer Verbesserung der Ergebnisse. Zum anderen wurde SWIM-live beispielhaft f{\"u}r einen Zyklus aus punktueller Modellverbesserung und fl{\"a}chiger {\"U}berpr{\"u}fung der Simulationsergebnisse genutzt. Die einzelnen Teilarbeiten tragen jeweils zur Dynamisierung von Klimafolgenanalysen im Elbegebiet bei. Der Anlass hierf{\"u}r war durch die fehlerhaften methodischen Grundlagen von STARS gegeben. Die Sinnf{\"a}lligkeit der Dynamisierung ist jedoch nicht an diesen konkreten Anlass gebunden, sondern beruht auf der grundlegenden Einsicht, dass Ad-hoc-Szenarienanalysen immer auch pragmatische Vereinfachungen zugrunde liegen, die fortlaufend {\"u}berpr{\"u}ft werden m{\"u}ssen.}, language = {de} } @article{ObuLantuitFritzetal.2016, author = {Obu, Jaroslav and Lantuit, Hugues and Fritz, Michael and Pollard, Wayne H. and Sachs, Torsten and Guenther, Frank}, title = {Relation between planimetric and volumetric measurements of permafrost coast erosion: a case study from Herschel Island, western Canadian Arctic}, series = {Polar research : a Norwegian journal of Polar research}, volume = {35}, journal = {Polar research : a Norwegian journal of Polar research}, publisher = {Co-Action Publ.}, address = {Jarfalla}, issn = {0800-0395}, doi = {10.3402/polar.v35.30313}, pages = {57 -- 99}, year = {2016}, abstract = {Ice-rich permafrost coasts often undergo rapid erosion, which results in land loss and release of considerable amounts of sediment, organic carbon and nutrients, impacting the near-shore ecosystems. Because of the lack of volumetric erosion data, Arctic coastal erosion studies typically report on planimetric erosion. Our aim is to explore the relationship between planimetric and volumetric coastal erosion measurements and to update the coastal erosion rates on Herschel Island in the Canadian Arctic. We used high-resolution digital elevation models to compute sediment release and compare volumetric data to planimetric estimations of coastline movements digitized from satellite imagery. Our results show that volumetric erosion is locally less variable and likely corresponds better with environmental forcing than planimetric erosion. Average sediment release volumes are in the same range as sediment release volumes calculated from coastline movements combined with cliff height. However, the differences between these estimates are significant for small coastal sections. We attribute the differences between planimetric and volumetric coastal erosion measurements to mass wasting, which is abundant along the coasts of Herschel Island. The average recorded coastline retreat on Herschel Island was 0.68m a(-1) for the period 2000-2011. Erosion rates increased by more than 50\% in comparison with the period 1970-2000, which is in accordance with a recently observed increase along the Alaskan Beaufort Sea. The estimated annual sediment release was 28.2 m(3) m(-1) with resulting fluxes of 590 kg C m(-1) and 104 kg N m(-1).}, language = {en} } @article{Rolfes2016, author = {Rolfes, Manfred}, title = {Sicherheit, Kriminalit{\"a}t und Raum}, series = {Politische Bildung im Geographieunterricht}, journal = {Politische Bildung im Geographieunterricht}, editor = {Budke, Alexandra and Kuckuck, Miriam}, publisher = {Steiner}, address = {Stuttgart}, isbn = {978-3-515-11321-2}, pages = {129 -- 140}, year = {2016}, language = {de} } @article{MartinezGarzonKwiatekBohnhoffetal.2016, author = {Martinez-Garzon, Patricia and Kwiatek, Grzegorz and Bohnhoff, Marco and Dresen, Georg}, title = {Impact of fluid injection on fracture reactivation at The Geysers geothermal field}, series = {Journal of geophysical research : Solid earth}, volume = {121}, journal = {Journal of geophysical research : Solid earth}, publisher = {American Geophysical Union}, address = {Washington}, issn = {2169-9313}, doi = {10.1002/2016JB013137}, pages = {7432 -- 7449}, year = {2016}, abstract = {We analyze the spatiotemporal distribution of fault geometries from seismicity induced by fluid injection at The Geysers geothermal field. The consistency of these faults with the local stress field is investigated using (1) the fault instability coefficient I comparing the orientation of a fault with the optimal orientation for failure in the assumed stress field and (2) the misfit angle beta between slip vectors observed from focal mechanisms and predicted from stress tensor. A statistical approach is applied to calculate the most likely fault instabilities considering the uncertainties from focal mechanisms and stress inversion. We find that faults activated by fluid injection may display a broad range in orientations. About 72\% of the analyzed seismicity occurs on faults with favorable orientation for failure with respect to the stress field. However, a number of events are observed either to occur on severely misoriented faults or to slip in a different orientation than predicted from stress field. These events mostly occur during periods of high injection rates and are located in proximity to the injection wells. From the stress inversion, the friction coefficient providing the largest overall instability is mu = 0.5. About 91\% of the events are activated with an estimated excess pore pressure <10 MPa, in agreement with previous models considering the combined effect of thermal and poroelastic stress changes from fluid injection. Furthermore, high seismic activity and largest magnitudes occur on favorably oriented faults with large instability coefficients and low slip misfit angles.}, language = {en} } @article{MunackBloetheFueloepetal.2016, author = {Munack, Henry and Bl{\"o}the, Jan Henrik and F{\"u}l{\"o}p, R. H. and Codilean, Alexandru T. and Fink, D. and Korup, Oliver}, title = {Recycling of Pleistocene valley fills dominates 135 ka of sediment flux, upper Indus River}, series = {Quaternary science reviews : the international multidisciplinary research and review journal}, volume = {149}, journal = {Quaternary science reviews : the international multidisciplinary research and review journal}, publisher = {Elsevier}, address = {Oxford}, issn = {0277-3791}, doi = {10.1016/j.quascirev.2016.07.030}, pages = {122 -- 134}, year = {2016}, language = {en} } @article{PanekKorupMinaretal.2016, author = {Panek, Tomas and Korup, Oliver and Minar, Jozef and Hradecky, Jan}, title = {Giant landslides and highstands of the Caspian Sea}, series = {Geology}, volume = {44}, journal = {Geology}, publisher = {American Institute of Physics}, address = {Boulder}, issn = {0091-7613}, doi = {10.1130/G38259.1}, pages = {939 -- 942}, year = {2016}, language = {en} } @article{SchwanghartWorniHuggeletal.2016, author = {Schwanghart, Wolfgang and Worni, Raphael and Huggel, Christian and Stoffel, Markus and Korup, Oliver}, title = {Uncertainty in the Himalayan energy-water nexus: estimating regional exposure to glacial lake outburst floods}, series = {Environmental research letters}, volume = {11}, journal = {Environmental research letters}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {1748-9326}, doi = {10.1088/1748-9326/11/7/074005}, pages = {9}, year = {2016}, abstract = {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.}, language = {en} } @article{SchwanghartBernhardtStolleetal.2016, author = {Schwanghart, Wolfgang and Bernhardt, Anne and Stolle, Amelie and Hoelzmann, Philipp and Adhikari, Basanta R. and Andermann, Christoff and Tofelde, Stefanie and Merchel, Silke and Rugel, Georg and Fort, Monique and Korup, Oliver}, title = {Repeated catastrophic valley infill following medieval earthquakes in the Nepal Himalaya}, series = {Science}, volume = {351}, journal = {Science}, publisher = {American Assoc. for the Advancement of Science}, address = {Washington}, issn = {0036-8075}, doi = {10.1126/science.aac9865}, pages = {147 -- 150}, year = {2016}, abstract = {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.}, language = {en} } @article{DoThiChinhBubeckNguyenVietDungetal.2016, author = {Do Thi Chinh, and Bubeck, Philip and Nguyen Viet Dung, and Kreibich, Heidi}, title = {The 2011 flood event in the Mekong Delta: preparedness, response, damage and recovery of private households and small businesses}, series = {Disasters : the journal of disaster studies, policy and management}, volume = {40}, journal = {Disasters : the journal of disaster studies, policy and management}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0361-3666}, doi = {10.1111/disa.12171}, pages = {753 -- 778}, year = {2016}, abstract = {Floods frequently cause substantial economic and human losses, particularly in developing countries. For the development of sound flood risk management schemes that reduce flood consequences, detailed insights into the different components of the flood risk management cycle, such as preparedness, response, flood impact analyses and recovery, are needed. However, such detailed insights are often lacking: commonly, only (aggregated) data on direct flood damage are available. Other damage categories such as losses owing to the disruption of production processes are usually not considered, resulting in incomplete risk assessments and possibly inappropriate recommendations for risk management. In this paper, data from 858 face-to-face interviews among flood-prone households and small businesses in Can Tho city in the Vietnamese Mekong Delta are presented to gain better insights into the damage caused by the 2011 flood event and its management by households and businesses.}, language = {en} } @article{MeereMulchroneMcCarthyetal.2016, author = {Meere, Patrick A. and Mulchrone, Kieran F. and McCarthy, Dave J. and Timmerman, Martin Jan and Dewey, John F.}, title = {Prelithification and synlithification tectonic foliation development in a clastic sedimentary sequence}, series = {Geology}, volume = {44}, journal = {Geology}, publisher = {American Institute of Physics}, address = {Boulder}, issn = {0091-7613}, doi = {10.1130/G37587.1}, pages = {291 -- 294}, year = {2016}, abstract = {The current view regarding the timing of regionally developed penetrative tectonic fabrics in sedimentary rocks is that their development postdates lithification of those rocks. In this case, fabric development is achieved by a number of deformation mechanisms, including grain rigid body rotation, crystal-plastic deformation, and pressure solution. The latter is believed to be the primary mechanism responsible for the domainal structure of cleavage in low-grade metamorphic rocks. In this study we combine field observations with strain studies to characterize considerable (>50\%) Acadian crustal shortening in a Devonian clastic sedimentary sequence from southwest Ireland. Despite these high levels of shortening there is a marked absence of the domainal cleavage structure and intraclast deformation that are expected with this level of deformation. Fabrics in these rocks are predominantly a product of rigid body rotation and repacking of extraformational clasts during deformation of a clastic sedimentary sequence before lithification was complete.}, language = {en} } @misc{MeereMulchroneMcCarthyetal.2016, author = {Meere, Patrick A. and Mulchrone, Kieran F. and McCarthy, David J. and Timmerman, Martin Jan and Dewey, John F.}, title = {Prelithification and synlithification tectonic foliation development in a clastic sedimentary sequence}, series = {Geology}, volume = {44}, journal = {Geology}, publisher = {American Institute of Physics}, address = {Boulder}, issn = {0091-7613}, doi = {10.1130/G38103Y.1}, pages = {E397 -- E397}, year = {2016}, language = {en} } @misc{BubeckAertsdeMoeletal.2016, author = {Bubeck, Philip and Aerts, Jeroen C. J. H. and de Moel, Hans and Kreibich, Heidi}, title = {Preface: Flood-risk analysis and integrated management}, series = {Natural hazards and earth system sciences}, volume = {16}, journal = {Natural hazards and earth system sciences}, publisher = {Copernicus}, address = {G{\"o}ttingen}, issn = {1561-8633}, doi = {10.5194/nhess-16-1005-2016}, pages = {1005 -- 1010}, year = {2016}, language = {en} } @misc{RadosavljevicLantuitPollardetal.2016, author = {Radosavljevic, Boris and Lantuit, Hugues and Pollard, Wayne and Overduin, Pier Paul and Couture, Nicole and Sachs, Torsten and Helm, Veit and Fritz, Michael}, title = {Erosion and Flooding - Threats to Coastal Infrastructure in the Arctic: A Case Study from Herschel Island, Yukon Territory, Canada (vol 39, pg 900, 2016)}, series = {Estuaries and coasts : journal of the Estuarine Research Federation}, volume = {39}, journal = {Estuaries and coasts : journal of the Estuarine Research Federation}, publisher = {Springer}, address = {New York}, issn = {1559-2723}, doi = {10.1007/s12237-016-0115-z}, pages = {1294 -- 1295}, year = {2016}, language = {en} } @article{FritzWolterRudayaetal.2016, author = {Fritz, Michael and Wolter, Juliane and Rudaya, Natalia and Palagushkina, Olga and Nazarova, Larisa B. and Obu, Jaroslav and Rethemeyer, Janet and Lantuit, Hugues and Wetterich, Sebastian}, title = {Holocene ice-wedge polygon development in northern Yukon permafrost peatlands (Canada)}, series = {Quaternary science reviews : the international multidisciplinary research and review journal}, volume = {147}, journal = {Quaternary science reviews : the international multidisciplinary research and review journal}, publisher = {Elsevier}, address = {Oxford}, issn = {0277-3791}, doi = {10.1016/j.quascirev.2016.02.008}, pages = {279 -- 297}, year = {2016}, abstract = {Ice-wedge polygon (IWP) peatlands in the Arctic and Subarctic are extremely vulnerable to climatic and environmental change. We present the results of a multidisciplinary paleoenvironmental study on IWPs in the northern Yukon, Canada. High-resolution laboratory analyses were carried out on a permafrost core and the overlying seasonally thawed (active) layer, from an IWP located in a drained lake basin on Herschel Island. In relation to 14 Accelerator Mass Spectrometry (AMS) radiocarbon dates spanning the last 5000 years, we report sedimentary data including grain size distribution and biogeochemical parameters (organic carbon, nitrogen, C/N ratio, delta C-13), stable water isotopes (delta O-18, delta D), as well as fossil pollen, plant macrofossil and diatom assemblages. Three sediment units (SUS) correspond to the main stages of deposition (1) in a thermokarst lake (SW : 4950 to 3950 cal yrs BP), (2) during transition from lacustrine to palustrine conditions after lake drainage (SU2: 3950 to 3120 cal yrs BP), and (3) in palustrine conditions of the IWP field that developed after drainage (SU3: 3120 cal yrs BP to 2012 CE). The lacustrine phase (pre 3950 cal yrs BP) is characterized by planktonic-benthic and pioneer diatom species indicating circumneutral waters, and very few plant macrofossils. The pollen record has captured a regional signal of relatively stable vegetation composition and climate for the lacustrine stage of the record until 3950 cal yrs BP. Palustrine conditions with benthic and acidophilic diatom species characterize the peaty shallow-water environments of the low-centered IWP. The transition from lacustrine to palustrine conditions was accompanied by acidification and rapid revegetation of the lake bottom within about 100 years. Since the palustrine phase we consider the pollen record as a local vegetation proxy dominated by the plant communities growing in the IWP. Ice-wedge cracking in water-saturated sediments started immediately after lake drainage at about 3950 cal yrs BP and led to the formation of an IWP mire. Permafrost aggradation through downward closed-system freezing of the lake talik is indicated by the stable water isotope record. The originally submerged IWP center underwent gradual drying during the past 2000 years. This study highlights the sensitivity of permafrost landscapes to climate and environmental change throughout the Holocene. (C) 2016 Elsevier Ltd. All rights reserved.}, language = {en} } @article{RadosavljevicLantuitPollardetal.2016, author = {Radosavljevic, Boris and Lantuit, Hugues and Pollard, Wayne and Overduin, Pier Paul and Couture, Nicole and Sachs, Torsten and Helm, Veit and Fritz, Michael}, title = {Erosion and Flooding-Threats to Coastal Infrastructure in the Arctic: A Case Study from Herschel Island, Yukon Territory, Canada}, series = {Estuaries and coasts : journal of the Estuarine Research Federation}, volume = {39}, journal = {Estuaries and coasts : journal of the Estuarine Research Federation}, publisher = {Springer}, address = {New York}, issn = {1559-2723}, doi = {10.1007/s12237-015-0046-0}, pages = {900 -- 915}, year = {2016}, abstract = {Arctic coastal infrastructure and cultural and archeological sites are increasingly vulnerable to erosion and flooding due to amplified warming of the Arctic, sea level rise, lengthening of open water periods, and a predicted increase in frequency of major storms. Mitigating these hazards necessitates decision-making tools at an appropriate scale. The objectives of this paper are to provide such a tool by assessing potential erosion and flood hazards at Herschel Island, a UNESCO World Heritage candidate site. This study focused on Simpson Point and the adjacent coastal sections because of their archeological, historical, and cultural significance. Shoreline movement was analyzed using the Digital Shoreline Analysis System (DSAS) after digitizing shorelines from 1952, 1970, 2000, and 2011. For purposes of this analysis, the coast was divided in seven coastal reaches (CRs) reflecting different morphologies and/or exposures. Using linear regression rates obtained from these data, projections of shoreline position were made for 20 and 50 years into the future. Flood hazard was assessed using a least cost path analysis based on a high-resolution light detection and ranging (LiDAR) dataset and current Intergovernmental Panel on Climate Change sea level estimates. Widespread erosion characterizes the study area. The rate of shoreline movement in different periods of the study ranges from -5.5 to 2.7 mI double dagger a(-1) (mean -0.6 mI double dagger a(-1)). Mean coastal retreat decreased from -0.6 mI double dagger a(-1) to -0.5 mI double dagger a(-1), for 1952-1970 and 1970-2000, respectively, and increased to -1.3 mI double dagger a(-1) in the period 2000-2011. Ice-rich coastal sections most exposed to wave attack exhibited the highest rates of coastal retreat. The geohazard map combines shoreline projections and flood hazard analyses to show that most of the spit area has extreme or very high flood hazard potential, and some buildings are vulnerable to coastal erosion. This study demonstrates that transgressive forcing may provide ample sediment for the expansion of depositional landforms, while growing more susceptible to overwash and flooding.}, language = {en} } @misc{SchwanghartWorniHuggeletal.2016, author = {Schwanghart, Wolfgang and Worni, Raphael and Huggel, Christian and Stoffel, Markus and Korup, Oliver}, title = {Uncertainty in the Himalayan energy-water nexus}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-97136}, pages = {9}, year = {2016}, abstract = {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.}, language = {en} } @article{SchwanghartWorniHuggeletal.2016, author = {Schwanghart, Wolfgang and Worni, Raphael and Huggel, Christian and Stoffel, Markus and Korup, Oliver}, title = {Uncertainty in the Himalayan energy-water nexus}, series = {Environmental research letters : ERL}, volume = {11}, journal = {Environmental research letters : ERL}, publisher = {IOP Publ.}, address = {Bristol}, issn = {1748-9326}, doi = {10.1088/1748-9326/11/7/074005}, pages = {9}, year = {2016}, abstract = {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.}, language = {en} } @article{EllingSpiegelEstradaetal.2016, author = {Elling, Felix J. and Spiegel, Cornelia and Estrada, Solveig and Davis, Donald W. and Reinhardt, Lutz and Henjes-Kunst, Friedhelm and Allroggen, Niklas and Dohrmann, Reiner and Piepjohn, Karsten and Lisker, Frank}, title = {Origin of Bentonites and Detrital Zircons of the Paleocene Basilika Formation, Svalbard}, series = {Frontiers in Earth Science}, volume = {4}, journal = {Frontiers in Earth Science}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {2296-6463}, doi = {10.3389/feart.2016.00073}, pages = {23}, year = {2016}, abstract = {The Paleocene was a time of transition for the Arctic, with magmatic activity of the High Arctic Large Igneous Province (HALIP) giving way to magmatism of the North Atlantic Large Igneous Province in connection to plate tectonic changes in the Arctic and North Atlantic. In this study we investigate the Paleocene magmatic record and sediment pathways of the Basilika Formation exposed in the Central Tertiary Basin of Svalbard. By means of geochemistry, SmNd isotopic signatures, and zircon UPb geochronology we investigate the characteristics of several bentonite layers contained in the Basilika Formation, as well as the provenance of the intercalated clastic sediments. Our data show that the volcanic ash layers of the Basilika Formation, which were diagenetically altered to bentonites, originate from alkaline continental-rift magmatism such as the last, explosive stages of the HALIP in North Greenland and the Canadian Arctic. The volcanic ash layers were deposited on Svalbard in a flat shelf environment with dominant sediment supply from the east. Dating of detrital zircons suggests that the detritus was derived from Siberian sources, primarily from the Verkhoyansk Fold-and-Thrust Belt, which would require transport over similar to 3000 km across the Arctic.}, language = {en} } @article{ToetzkeGaiselmannOsenbergetal.2016, author = {T{\"o}tzke, Christian and Gaiselmann, G. and Osenberg, M. and Arlt, T. and Mark{\"o}tter, H. and Hilger, A. and Kupsch, Andreas and M{\"u}ller, B. R. and Schmidt, V. and Lehnert, W. and Manke, Ingo}, title = {Influence of hydrophobic treatment on the structure of compressed gas diffusion layers}, series = {Journal of power sources : the international journal on the science and technology of electrochemical energy systems}, volume = {324}, journal = {Journal of power sources : the international journal on the science and technology of electrochemical energy systems}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0378-7753}, doi = {10.1016/j.jpowsour.2016.05.118}, pages = {625 -- 636}, year = {2016}, abstract = {Carbon fiber based felt materials are widely used as gas diffusion layer (GDL) in fuel cells. Their transport properties can be adjusted by adding hydrophobic agents such as polytetrafluoroethylene (PTFE). We present a synchrotron X-ray tomographic study on the felt material Freudenberg H2315 with different PIPE finishing. In this study, we analyze changes in microstructure and shape of GDLs at increasing degree of compression which are related to their specific PTFE load. A dedicated compression device mimicking the channel-land pattern of the flowfield is used to reproduce the inhomogeneous compression found in a fuel cell. Transport relevant geometrical parameters such as porosity, pore size distribution and geometric tortuosity are calculated and consequences for media transport discussed. PTFE finishing results in a marked change of shape of compressed GDLs: surface is smoothed and the invasion of GDL fibers into the flow field channel strongly mitigated. Furthermore, the PTFE impacts the microstructure of the compressed GDL. The number of available wide transport paths is significantly increased as compared to the untreated material. These changes improve the transport capacity liquid water through the GDL and promote the discharge of liquid water droplets from the cell. (C) 2016 Elsevier B.V. All rights reserved.}, language = {en} } @article{UlloaIroumePiccoetal.2016, author = {Ulloa, H. and Iroume, A. and Picco, L. and Mohr, Christian Heinrich and Mazzorana, B. and Lenzi, Mario Aristide and Mao, L.}, title = {Spatial analysis of the impacts of the Chaiten volcano eruption (Chile) in three fluvial systems}, series = {Journal of South American earth sciences}, volume = {69}, journal = {Journal of South American earth sciences}, publisher = {Elsevier}, address = {Oxford}, issn = {0895-9811}, doi = {10.1016/j.jsames.2016.04.008}, pages = {213 -- 225}, year = {2016}, abstract = {The eruption of the Chaiten volcano in May 2008 generated morphological and ecological disturbances in adjacent river basins, and the magnitude of these disturbances depended on the type of dominant volcanic process affecting each of them. The aim of this study is to analyse the morphological changes in different periods in river segments of the Blanco, El Amarillo and Rayas river basins located near the Chaiten volcano. These basins suffered disturbances of different intensity and spatial distribution caused by tephra fall, dome collapses and pyroclastic density currents that damaged hillslope forests, widened channels and destroyed island and floodplain vegetation. Changes continued to occur in the fluvial systems in the years following the eruption, as a consequence of the geomorphic processes indirectly induced by the eruption. Channel changes were analyzed by comparing remote images of pre and post eruption conditions. Two periods were considered: the first from 2008 to 2009-2010 associated with the explosive and effusive phases of the eruption and the second that correspond to the post-eruption stage from 2009-2010 to 2013. Following the first phases channel segments widened 91\% (38 m/yr), 6\% (7 m/yr) and 7\% (22 m/yr) for Blanco, Rayas and El Amarillo Rivers, respectively, compared to pre-eruption condition. In the second period, channel segments additionally widened 42\% (8 m/yr), 2\% (2 m/yr) and 5\% (4 m/yr) for Blanco, Rayas and El Amarillo Rivers, respectively. In the Blanco River 62 and 82\% of the islands disappeared in the first and second period, respectively, which is 6-8 times higher than in the El Amarillo approximately twice the Rayas. Sinuosity increased after the eruption only in the Blanco River but the three study channels showed a high braiding intensity mainly during the first post-eruption period. The major disturbances occurred during the eruptive and effusive phases of Chaiten volcano, and the intensity of these disturbances reflects the magnitude of the dominant volcanic processes affecting each basin. Inputs of sediment from dome collapses and pyroclastic density currents and not ash fall seem to explain morphologic channel change magnitudes in the study segments. The resulting knowledge can facilitate land use planning and design of river restoration projects in areas affected by volcanic eruptions disturbances. (C) 2016 Elsevier Ltd. All rights reserved.}, language = {en} } @misc{GliegeThomasSteidletal.2016, author = {Gliege, Steffen and Thomas, Bj{\"o}rn Daniel and Steidl, J{\"o}rg and Hohenbrink, Tobias Ludwig and Dietrich, Ottfried}, title = {Modeling the impact of ditch water level management on stream-aquifer interactions}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-407613}, pages = {17}, year = {2016}, abstract = {Decreasing groundwater levels in many parts of Germany and decreasing low flows in Central Europe have created a need for adaptation measures to stabilize the water balance and to increase low flows. The objective of our study was to estimate the impact of ditch water level management on stream-aquifer interactions in small lowland catchments of the mid-latitudes. The water balance of a ditch-irrigated area and fluxes between the subsurface and the adjacent stream were modeled for three runoff recession periods using the Hydrus-2D software package. The results showed that the subsurface flow to the stream was closely related to the difference between the water level in the ditch system and the stream. Evapotranspiration during the growing season additionally reduced base flow. It was crucial to stop irrigation during a recession period to decrease water withdrawal from the stream and enhance the base flow by draining the irrigated area. Mean fluxes to the stream were between 0.04 and 0.64 ls(-1) for the first 20 days of the low-flow periods. This only slightly increased the flow in the stream, whose mean was 57 ls(-1) during the period with the lowest flows. Larger areas would be necessary to effectively increase flows in mesoscale catchments.}, language = {en} } @misc{AdhikariGlombitzaNickeletal.2016, author = {Adhikari, Rishi Ram and Glombitza, Clemens and Nickel, Julia C. and Anderson, Chloe H. and Dunlea, Ann G. and Spivack, Arthur J. and Murray, Richard W. and D'Hondt, Steven and Kallmeyer, Jens}, title = {Hydrogen utilization potential in subsurface sediments}, series = {Frontiers in microbiology}, journal = {Frontiers in microbiology}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-407678}, pages = {16}, year = {2016}, abstract = {Subsurface microbial communities undertake many terminal electron-accepting processes, often simultaneously. Using a tritium-based assay, we measured the potential hydrogen oxidation catalyzed by hydrogenase enzymes in several subsurface sedimentary environments (Lake Van, Barents Sea, Equatorial Pacific, and Gulf of Mexico) with different predominant electron-acceptors. Hydrogenases constitute a diverse family of enzymes expressed by microorganisms that utilize molecular hydrogen as a metabolic substrate, product, or intermediate. The assay reveals the potential for utilizing molecular hydrogen and allows qualitative detection of microbial activity irrespective of the predominant electron-accepting process. Because the method only requires samples frozen immediately after recovery, the assay can be used for identifying microbial activity in subsurface ecosystems without the need to preserve live material. We measured potential hydrogen oxidation rates in all samples from multiple depths at several sites that collectively span a wide range of environmental conditions and biogeochemical zones. Potential activity normalized to total cell abundance ranges over five orders of magnitude and varies, dependent upon the predominant terminal electron acceptor. Lowest per-cell potential rates characterize the zone of nitrate reduction and highest per-cell potential rates occur in the methanogenic zone. Possible reasons for this relationship to predominant electron acceptor include (i) increasing importance of fermentation in successively deeper biogeochemical zones and (ii) adaptation of H(2)ases to successively higher concentrations of H-2 in successively deeper zones.}, language = {en} } @misc{WehrhanRaunekerSommer2016, author = {Wehrhan, Marc and Rauneker, Philipp and Sommer, Michael}, title = {UAV-Based estimation of carbon exports from heterogeneous soil landscapes}, series = {Sensors}, journal = {Sensors}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-407706}, pages = {24}, year = {2016}, abstract = {The advantages of remote sensing using Unmanned Aerial Vehicles (UAVs) are a high spatial resolution of images, temporal flexibility and narrow-band spectral data from different wavelengths domains. This enables the detection of spatio-temporal dynamics of environmental variables, like plant-related carbon dynamics in agricultural landscapes. In this paper, we quantify spatial patterns of fresh phytomass and related carbon (C) export using imagery captured by a 12-band multispectral camera mounted on the fixed wing UAV Carolo P360. The study was performed in 2014 at the experimental area CarboZALF-D in NE Germany. From radiometrically corrected and calibrated images of lucerne (Medicago sativa), the performance of four commonly used vegetation indices (VIs) was tested using band combinations of six near-infrared bands. The highest correlation between ground-based measurements of fresh phytomass of lucerne and VIs was obtained for the Enhanced Vegetation Index (EVI) using near-infrared band b(899). The resulting map was transformed into dry phytomass and finally upscaled to total C export by harvest. The observed spatial variability at field- and plot-scale could be attributed to small-scale soil heterogeneity in part.}, language = {en} } @misc{DietrichSchweigertSteidletal.2016, author = {Dietrich, Ottfried and Schweigert, Susanne and Steidl, J{\"o}rg and Lischeid, Gunnar}, title = {Effects of data and model simplification on the results of a wetland water resource management model}, series = {Water}, journal = {Water}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-407579}, pages = {19}, year = {2016}, abstract = {This paper presents the development of a wetland water balance model for use in a large river basin with many different wetlands. The basic model was primarily developed for a single wetland with a complex water management system involving large amounts of specialized input data and water management details. The aim was to simplify the model structure and to use only commonly available data as input for the model, with the least possible loss of accuracy. Results from different variants of the model and data adaptation were tested against results from a detailed model. This shows that using commonly available data and unifying and simplifying the input data is tolerable up to a certain level. The simplification of the model has greater effects on the evaluated water balance components than the data adaptation. Because this simplification was necessary for large-scale use, we suggest that, for reasons of comparability, simpler models should always be applied with uniform data bases for large regions, though these should only be moderately simplified. Further, we recommend using these simplified models only for large-scale comparisons and using more specific, detailed models for investigations on smaller scales.}, language = {en} } @misc{SinghSeitzEickeretal.2016, author = {Singh, Alka and Seitz, Florian and Eicker, Annette and G{\"u}ntner, Andreas}, title = {Water budget analysis within the surrounding of prominent lakes and reservoirs from multi-sensor earth observation data and hydrological models}, series = {remote sensing}, journal = {remote sensing}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-407902}, pages = {21}, year = {2016}, abstract = {The hydrological budget of a region is determined based on the horizontal and vertical water fluxes acting in both inward and outward directions. These integrated water fluxes vary, altering the total water storage and consequently the gravitational force of the region. The time-dependent gravitational field can be observed through the Gravity Recovery and Climate Experiment (GRACE) gravimetric satellite mission, provided that the mass variation is above the sensitivity of GRACE. This study evaluates mass changes in prominent reservoir regions through three independent approaches viz. fluxes, storages, and gravity, by combining remote sensing products, in-situ data and hydrological model outputs using WaterGAP Global Hydrological Model (WGHM) and Global Land Data Assimilation System (GLDAS). The results show that the dynamics revealed by the GRACE signal can be better explored by a hybrid method, which combines remote sensing-based reservoir volume estimates with hydrological model outputs, than by exclusive model-based storage estimates. For the given arid/ semi-arid regions, GLDAS based storage estimations perform better than WGHM.}, language = {en} } @misc{HollsteinSeglGuanteretal.2016, author = {Hollstein, Andr{\´e} and Segl, Karl and Guanter, Luis and Brell, Maximilian and Enesco, Marta}, title = {Ready-to-Use methods for the detection of clouds, cirrus, snow, shadow, water and clear sky pixels in Sentinel-2 MSI images}, series = {remote sensing}, journal = {remote sensing}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-407938}, pages = {18}, year = {2016}, abstract = {Classification of clouds, cirrus, snow, shadows and clear sky areas is a crucial step in the pre-processing of optical remote sensing images and is a valuable input for their atmospheric correction. The Multi-Spectral Imager on board the Sentinel-2's of the Copernicus program offers optimized bands for this task and delivers unprecedented amounts of data regarding spatial sampling, global coverage, spectral coverage, and repetition rate. Efficient algorithms are needed to process, or possibly reprocess, those big amounts of data. Techniques based on top-of-atmosphere reflectance spectra for single-pixels without exploitation of external data or spatial context offer the largest potential for parallel data processing and highly optimized processing throughput. Such algorithms can be seen as a baseline for possible trade-offs in processing performance when the application of more sophisticated methods is discussed. We present several ready-to-use classification algorithms which are all based on a publicly available database of manually classified Sentinel-2A images. These algorithms are based on commonly used and newly developed machine learning techniques which drastically reduce the amount of time needed to update the algorithms when new images are added to the database. Several ready-to-use decision trees are presented which allow to correctly label about 91\% of the spectra within a validation dataset. While decision trees are simple to implement and easy to understand, they offer only limited classification skill. It improves to 98\% when the presented algorithm based on the classical Bayesian method is applied. This method has only recently been used for this task and shows excellent performance concerning classification skill and processing performance. A comparison of the presented algorithms with other commonly used techniques such as random forests, stochastic gradient descent, or support vector machines is also given. Especially random forests and support vector machines show similar classification skill as the classical Bayesian method.}, language = {en} } @misc{SiegmundSandersHeinrichetal.2016, author = {Siegmund, Jonatan Frederik and Sanders, Tanja G. M. and Heinrich, Ingo and Maaten, Ernst van der and Simard, Sonia and Helle, Gerhard and Donner, Reik Volker}, title = {Meteorological drivers of extremes in daily stem radius variations of beech, oak, and pine in Northeastern Germany}, series = {Frontiers in plant science}, journal = {Frontiers in plant science}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-407943}, pages = {14}, year = {2016}, abstract = {Observed recent and expected future increases in frequency and intensity of climatic extremes in central Europe may pose critical challenges for domestic tree species. Continuous dendrometer recordings provide a valuable source of information on tree stem radius variations, offering the possibility to study a tree's response to environmental influences at a high temporal resolution. In this study, we analyze stem radius variations (SRV) of three domestic tree species (beech, oak, and pine) from 2012 to 2014. We use the novel statistical approach of event coincidence analysis (ECA) to investigate the simultaneous occurrence of extreme daily weather conditions and extreme SRVs, where extremes are defined with respect to the common values at a given phase of the annual growth period. Besides defining extreme events based on individual meteorological variables, we additionally introduce conditional and joint ECA as new multivariate extensions of the original methodology and apply them for testing 105 different combinations of variables regarding their impact on SRV extremes. Our results reveal a strong susceptibility of all three species to the extremes of several meteorological variables. Yet, the inter-species differences regarding their response to the meteorological extremes are comparatively low. The obtained results provide a thorough extension of previous correlation-based studies by emphasizing on the timings of climatic extremes only. We suggest that the employed methodological approach should be further promoted in forest research regarding the investigation of tree responses to changing environmental conditions.}, language = {en} } @article{LozanoParravanSchaikSchnabeletal.2016, author = {Lozano-Parra, Javier and van Schaik, N. Loes M. B. and Schnabel, Susanne and Gomez-Gutierrez, Alvaro}, title = {Soil moisture dynamics at high temporal resolution in a semiarid Mediterranean watershed with scattered tree cover}, series = {Hydrological processes}, volume = {30}, journal = {Hydrological processes}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0885-6087}, doi = {10.1002/hyp.10694}, pages = {1155 -- 1170}, year = {2016}, abstract = {Subsurface water flows play a key role in the distribution of water and solutes and thereby in the water availability for plants. However, the characterization of different flow processes (i.e.matrix and preferential flow), the frequency and factors that cause them, is relatively rare. This characterization enables a better understanding of spatio-temporal variability of water resources and allows for the design of models to be improved. Using a method based on the time derivative of soil moisture variation known as maximum wetting slope, types of soil wetting processes were classified and quantified. For this, capacitance sensors, which registered the volumetric water content at high temporal resolution (30min) for more than two hydrological years, were installed at different depths and placed in soil moisture stations with different vegetation covers, lithology and topographic position. Results indicated that there is a general behaviour or pattern of soil moisture dynamics in the catchment with a dominant occurrence of slower soil wetting processes (>50\%), caused by matrix flows, and a low occurrence of those faster processes (<30\%), originated by preferential flows. Nevertheless, when the total volume of water is considered, preferential flow becomes the dominant process, so that the ecological role of both flow types becomes prominent in water-limited environments. Statistical multivariate analyses based on data-mining techniques proved that although both flow types depend on variables associated with precipitation and antecedent soil moisture conditions, faster soil wetting processes are mainly related to variables such as rainfall intensity and topography, while slower soil wetting processes are related to flow velocity, soils or vegetation. Copyright (c) 2015 John Wiley \& Sons, Ltd.}, language = {en} } @misc{SchmidtSachseWalz2016, author = {Schmidt, Katja and Sachse, Rene and Walz, Ariane}, title = {Current role of social benefits in ecosystem service assessments}, series = {Landscape and urban planning : an international journal of landscape ecology, planning and design}, volume = {149}, journal = {Landscape and urban planning : an international journal of landscape ecology, planning and design}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0169-2046}, doi = {10.1016/j.landurbplan.2016.01.005}, pages = {49 -- 64}, year = {2016}, abstract = {Ecosystem services have a significant impact on human wellbeing. While ecosystem services are frequently represented by monetary values, social values and underlying social benefits remain underexplored. The purpose of this study is to assess whether and how social benefits have been explicitly addressed within socio-economic and socio-cultural ecosystem services research, ultimately allowing a better understanding between ecosystem services and human well-being. In this paper, we reviewed 115 international primary valuation studies and tested four hypotheses associated to the identification of social benefits of ecosystem services using logistic regressions. Tested hypotheses were that (1) social benefits are mostly derived in studies that assess cultural ecosystem services as opposed to other ecosystem service types, (2) there is a pattern of social benefits and certain cultural ecosystem services assessed simultaneously, (3) monetary valuation techniques go beyond expressing monetary values and convey social benefits, and (4) directly addressing stakeholde\&\#341;s views the consideration of social benefits in ecosystem service assessments. Our analysis revealed that (1) a variety of social benefits are valued in studies that assess either of the four ecosystem service types, (2) certain social benefits are likely to co-occur in combination with certain cultural ecosystem services, (3) of the studies that employed monetary valuation techniques, simulated market approaches overlapped most frequently with the assessment of social benefits and (4) studies that directly incorporate stakeholder's views were more likely to also assess social benefits.}, language = {en} } @article{KruegerMaynardCarretal.2016, author = {Krueger, Tobias and Maynard, Carly and Carr, Gemma and Bruns, Antje and M{\"u}ller, Eva Nora and Lane, Stuart}, title = {A transdisciplinary account of water research}, series = {Wiley Interdisciplinary Reviews : Water}, volume = {3}, journal = {Wiley Interdisciplinary Reviews : Water}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {2049-1948}, doi = {10.1002/wat2.1132}, pages = {369 -- 389}, year = {2016}, abstract = {Water research is introduced from the combined perspectives of natural and social science and cases of citizen and stakeholder coproduction of knowledge. Using the overarching notion of transdisciplinarity, we examine how interdisciplinary and participatory water research has taken place and could be developed further. It becomes apparent that water knowledge is produced widely within society, across certified disciplinary experts and noncertified expert stakeholders and citizens. However, understanding and management interventions may remain partial, or even conflicting, as much research across and between traditional disciplines has failed to integrate disciplinary paradigms due to philosophical, methodological, and communication barriers. We argue for more agonistic relationships that challenge both certified and noncertified knowledge productively. These should include examination of how water research itself embeds and is embedded in social context and performs political work. While case studies of the cultural and political economy of water knowledge exist, we need more empirical evidence on how exactly culture, politics, and economics have shaped this knowledge and how and at what junctures this could have turned out differently. We may thus channel the coproductionist critique productively to bring perspectives, alternative knowledges, and implications into water politics where they were not previously considered; in an attempt to counter potential lock-in to particular water policies and technologies that may be inequitable, unsustainable, or unacceptable. While engaging explicitly with politics, transdisciplinary water research should remain attentive to closing down moments in the research process, such as framings, path-dependencies, vested interests, researchers' positionalities, power, and scale.}, language = {en} } @article{WahaZipfKurukulasuriyaetal.2016, author = {Waha, Katharina and Zipf, Birgit and Kurukulasuriya, Pradeep and Hassan, Rashid M.}, title = {An agricultural survey for more than 9,500 African households}, series = {Scientific Data}, volume = {3}, journal = {Scientific Data}, publisher = {Nature Publ. Group}, address = {London}, issn = {2052-4463}, doi = {10.1038/sdata.2016.20}, pages = {8}, year = {2016}, abstract = {Surveys for more than 9,500 households were conducted in the growing seasons 2002/2003 or 2003/2004 in eleven African countries: Burkina Faso, Cameroon, Ghana, Niger and Senegal in western Africa; Egypt in northern Africa; Ethiopia and Kenya in eastern Africa; South Africa, Zambia and Zimbabwe in southern Africa. Households were chosen randomly in districts that are representative for key agro-climatic zones and farming systems. The data set specifies farming systems characteristics that can help inform about the importance of each system for a country's agricultural production and its ability to cope with short- and long-term climate changes or extreme weather events. Further it informs about the location of smallholders and vulnerable systems and permits benchmarking agricultural systems characteristics.}, language = {en} }