@misc{Voland2014, type = {Master Thesis}, author = {Voland, Patrick}, title = {Webbasierte Visualisierung von Extended Floating Car Data (XFCD)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-96751}, school = {Universit{\"a}t Potsdam}, pages = {VIII, 176}, year = {2014}, abstract = {Moderne Kraftfahrzeuge verf{\"u}gen {\"u}ber eine Vielzahl an Sensoren, welche f{\"u}r einen reibungslosen technischen Betrieb ben{\"o}tigt werden. Hierzu z{\"a}hlen neben fahrzeugspezifischen Sensoren (wie z.B. Motordrehzahl und Fahrzeuggeschwindigkeit) auch umweltspezifische Sensoren (wie z.B. Luftdruck und Umgebungstemperatur). Durch die zunehmende technische Vernetzung wird es m{\"o}glich, diese Daten der Kraftfahrzeugelektronik aus dem Fahrzeug heraus f{\"u}r die verschiedensten Zwecke zu verwenden. Die vorliegende Arbeit soll einen Beitrag dazu leisten, diese neue Art an massenhaften Daten im Sinne des Konzepts der „Extended Floating Car Data" (XFCD) als Geoinformationen nutzbar zu machen und diese f{\"u}r raumzeitliche Visualisierungen (zur visuellen Analyse) anwenden zu k{\"o}nnen. In diesem Zusammenhang wird speziell die Perspektive des Umwelt- und Verkehrsmonitoring betrachtet, wobei die Anforderungen und Potentiale mit Hilfe von Experteninterviews untersucht werden. Es stellt sich die Frage, welche Daten durch die Kraftfahrzeugelektronik geliefert und wie diese m{\"o}glichst automatisiert erfasst, verarbeitet, visualisiert und {\"o}ffentlich bereitgestellt werden k{\"o}nnen. Neben theoretischen und technischen Grundlagen zur Datenerfassung und -nutzung liegt der Fokus auf den Methoden der kartographischen Visualisierung. Dabei soll der Frage nachgegangenen werden, ob eine technische Implementierung ausschließlich unter Verwendung von Open Source Software m{\"o}glich ist. Das Ziel der Arbeit bildet ein zweigliedriger Ansatz, welcher zum einen die Visualisierung f{\"u}r ein exemplarisch gew{\"a}hltes Anwendungsszenario und zum anderen die prototypische Implementierung von der Datenerfassung im Fahrzeug unter Verwendung der gesetzlich vorgeschriebenen „On Board Diagnose"-Schnittstelle und einem Smartphone-gest{\"u}tzten Ablauf bis zur webbasierten Visualisierung umfasst.}, language = {de} } @article{ZoellerHolschneiderHainzletal.2014, author = {Z{\"o}ller, Gert and Holschneider, Matthias and Hainzl, Sebastian and Zhuang, Jiancang}, title = {The largest expected earthquake magnitudes in Japan: The statistical perspective}, series = {Bulletin of the Seismological Society of America}, volume = {104}, journal = {Bulletin of the Seismological Society of America}, number = {2}, publisher = {Seismological Society of America}, address = {Albany}, issn = {0037-1106}, doi = {10.1785/0120130103}, pages = {769 -- 779}, year = {2014}, abstract = {Earthquake catalogs are probably the most informative data source about spatiotemporal seismicity evolution. The catalog quality in one of the most active seismogenic zones in the world, Japan, is excellent, although changes in quality arising, for example, from an evolving network are clearly present. Here, we seek the best estimate for the largest expected earthquake in a given future time interval from a combination of historic and instrumental earthquake catalogs. We extend the technique introduced by Zoller et al. (2013) to estimate the maximum magnitude in a time window of length T-f for earthquake catalogs with varying level of completeness. In particular, we consider the case in which two types of catalogs are available: a historic catalog and an instrumental catalog. This leads to competing interests with respect to the estimation of the two parameters from the Gutenberg-Richter law, the b-value and the event rate lambda above a given lower-magnitude threshold (the a-value). The b-value is estimated most precisely from the frequently occurring small earthquakes; however, the tendency of small events to cluster in aftershocks, swarms, etc. violates the assumption of a Poisson process that is used for the estimation of lambda. We suggest addressing conflict by estimating b solely from instrumental seismicity and using large magnitude events from historic catalogs for the earthquake rate estimation. Applying the method to Japan, there is a probability of about 20\% that the maximum expected magnitude during any future time interval of length T-f = 30 years is m >= 9.0. Studies of different subregions in Japan indicates high probabilities for M 8 earthquakes along the Tohoku arc and relatively low probabilities in the Tokai, Tonankai, and Nankai region. Finally, for scenarios related to long-time horizons and high-confidence levels, the maximum expected magnitude will be around 10.}, language = {en} } @book{Ehebrecht2014, author = {Ehebrecht, Daniel}, title = {The challenge of informal settlement upgrading : Breaking new ground in Hangberg, Cape Town?}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-300-8}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-71232}, publisher = {Universit{\"a}t Potsdam}, pages = {184}, year = {2014}, abstract = {Despite its many challenges and limitations the concept of in situ upgrading of informal settlements has become one of the most favoured approaches to the housing crisis in the 'Global South'. Due to its inherent principles of incremental in situ development, prevention of relocations, protection of local livelihoods and democratic participation and cooperation, this approach is often perceived to be more sustainable than other housing approaches that often rely on quantitative housing delivery and top down planning methodologies. While this study does not question the benefits of the in situ upgrading approach, it seeks to identify problems of its practical implementation within a specific national and local context. The study discusses the origin and importance of this approach on the basis of a review of international housing policy development and analyses the broader political and social context of the incorporation of this approach into South African housing policy. It further uses insights from a recent case study in Cape Town to determine complications and conflicts that can arise when applying in situ upgrading of informal settlements in a complex local context. On that basis benefits and limitations of the in situ upgrading approach are specified and prerequisites for its successful implementation formulated.}, language = {en} } @phdthesis{Zibulski2014, author = {Zibulski, Romy}, title = {Taxonomic composition and biochemical and isotopic characteristics of North-Siberian mosses and their application to the palaeoecological reconstruction of tundra polygon development}, pages = {ii, 127}, year = {2014}, language = {en} } @phdthesis{Bamberg2014, author = {Bamberg, Marlene}, title = {Planetary mapping tools applied to floor-fractured craters on Mars}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-72104}, school = {Universit{\"a}t Potsdam}, year = {2014}, abstract = {Planetary research is often user-based and requires considerable skill, time, and effort. Unfortunately, self-defined boundary conditions, definitions, and rules are often not documented or not easy to comprehend due to the complexity of research. This makes a comparison to other studies, or an extension of the already existing research, complicated. Comparisons are often distorted, because results rely on different, not well defined, or even unknown boundary conditions. The purpose of this research is to develop a standardized analysis method for planetary surfaces, which is adaptable to several research topics. The method provides a consistent quality of results. This also includes achieving reliable and comparable results and reducing the time and effort of conducting such studies. A standardized analysis method is provided by automated analysis tools that focus on statistical parameters. Specific key parameters and boundary conditions are defined for the tool application. The analysis relies on a database in which all key parameters are stored. These databases can be easily updated and adapted to various research questions. This increases the flexibility, reproducibility, and comparability of the research. However, the quality of the database and reliability of definitions directly influence the results. To ensure a high quality of results, the rules and definitions need to be well defined and based on previously conducted case studies. The tools then produce parameters, which are obtained by defined geostatistical techniques (measurements, calculations, classifications). The idea of an automated statistical analysis is tested to proof benefits but also potential problems of this method. In this study, I adapt automated tools for floor-fractured craters (FFCs) on Mars. These impact craters show a variety of surface features, occurring in different Martian environments, and having different fracturing origins. They provide a complex morphological and geological field of application. 433 FFCs are classified by the analysis tools due to their fracturing process. Spatial data, environmental context, and crater interior data are analyzed to distinguish between the processes involved in floor fracturing. Related geologic processes, such as glacial and fluvial activity, are too similar to be separately classified by the automated tools. Glacial and fluvial fracturing processes are merged together for the classification. The automated tools provide probability values for each origin model. To guarantee the quality and reliability of the results, classification tools need to achieve an origin probability above 50 \%. This analysis method shows that 15 \% of the FFCs are fractured by intrusive volcanism, 20 \% by tectonic activity, and 43 \% by water \& ice related processes. In total, 75 \% of the FFCs are classified to an origin type. This can be explained by a combination of origin models, superposition or erosion of key parameters, or an unknown fracturing model. Those features have to be manually analyzed in detail. Another possibility would be the improvement of key parameters and rules for the classification. This research shows that it is possible to conduct an automated statistical analysis of morphologic and geologic features based on analysis tools. Analysis tools provide additional information to the user and are therefore considered assistance systems.}, language = {en} } @phdthesis{Strauss2014, author = {Strauß, Jens}, title = {Organic carbon in ice-rich permafrost}, doi = {10.25932/publishup-7523}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-75236}, school = {Universit{\"a}t Potsdam}, pages = {XIII, 107, 102}, year = {2014}, abstract = {Permafrost, defined as ground that is frozen for at least two consecutive years, is a distinct feature of the terrestrial unglaciated Arctic. It covers approximately one quarter of the land area of the Northern Hemisphere (23,000,000 km²). Arctic landscapes, especially those underlain by permafrost, are threatened by climate warming and may degrade in different ways, including active layer deepening, thermal erosion, and development of rapid thaw features. In Siberian and Alaskan late Pleistocene ice-rich Yedoma permafrost, rapid and deep thaw processes (called thermokarst) can mobilize deep organic carbon (below 3 m depth) by surface subsidence due to loss of ground ice. Increased permafrost thaw could cause a feedback loop of global significance if its stored frozen organic carbon is reintroduced into the active carbon cycle as greenhouse gases, which accelerate warming and inducing more permafrost thaw and carbon release. To assess this concern, the major objective of the thesis was to enhance the understanding of the origin of Yedoma as well as to assess the associated organic carbon pool size and carbon quality (concerning degradability). The key research questions were: - How did Yedoma deposits accumulate? - How much organic carbon is stored in the Yedoma region? - What is the susceptibility of the Yedoma region's carbon for future decomposition? To address these three research questions, an interdisciplinary approach, including detailed field studies and sampling in Siberia and Alaska as well as methods of sedimentology, organic biogeochemistry, remote sensing, statistical analyses, and computational modeling were applied. To provide a panarctic context, this thesis additionally includes results both from a newly compiled northern circumpolar carbon database and from a model assessment of carbon fluxes in a warming Arctic. The Yedoma samples show a homogeneous grain-size composition. All samples were poorly sorted with a multi-modal grain-size distribution, indicating various (re-) transport processes. This contradicts the popular pure loess deposition hypothesis for the origin of Yedoma permafrost. The absence of large-scale grinding processes via glaciers and ice sheets in northeast Siberian lowlands, processes which are necessary to create loess as material source, suggests the polygenetic origin of Yedoma deposits. Based on the largest available data set of the key parameters, including organic carbon content, bulk density, ground ice content, and deposit volume (thickness and coverage) from Siberian and Alaskan study sites, this thesis further shows that deep frozen organic carbon in the Yedoma region consists of two distinct major reservoirs, Yedoma deposits and thermokarst deposits (formed in thaw-lake basins). Yedoma deposits contain ~80 Gt and thermokarst deposits ~130 Gt organic carbon, or a total of ~210 Gt. Depending on the approach used for calculating uncertainty, the range for the total Yedoma region carbon store is ±75 \% and ±20 \% for conservative single and multiple bootstrapping calculations, respectively. Despite the fact that these findings reduce the Yedoma region carbon pool by nearly a factor of two compared to previous estimates, this frozen organic carbon is still capable of inducing a permafrost carbon feedback to climate warming. The complete northern circumpolar permafrost region contains between 1100 and 1500 Gt organic carbon, of which ~60 \% is perennially frozen and decoupled from the short-term carbon cycle. When thawed and reintroduced into the active carbon cycle, the organic matter qualities become relevant. Furthermore, results from investigations into Yedoma and thermokarst organic matter quality studies showed that Yedoma and thermokarst organic matter exhibit no depth-dependent quality trend. This is evidence that after freezing, the ancient organic matter is preserved in a state of constant quality. The applied alkane and fatty-acid-based biomarker proxies including the carbon-preference and the higher-land-plant-fatty-acid indices show a broad range of organic matter quality and thus no significantly different qualities of the organic matter stored in thermokarst deposits compared to Yedoma deposits. This lack of quality differences shows that the organic matter biodegradability depends on different decomposition trajectories and the previous decomposition/incorporation history. Finally, the fate of the organic matter has been assessed by implementing deep carbon pools and thermokarst processes in a permafrost carbon model. Under various warming scenarios for the northern circumpolar permafrost region, model results show a carbon release from permafrost regions of up to ~140 Gt and ~310 Gt by the years 2100 and 2300, respectively. The additional warming caused by the carbon release from newly-thawed permafrost contributes 0.03 to 0.14°C by the year 2100. The model simulations predict that a further increase by the 23rd century will add 0.4°C to global mean surface air temperatures. In conclusion, Yedoma deposit formation during the late Pleistocene was dominated by water-related (alluvial/fluvial/lacustrine) as well as aeolian processes under periglacial conditions. The circumarctic permafrost region, including the Yedoma region, contains a substantial amount of currently frozen organic carbon. The carbon of the Yedoma region is well-preserved and therefore available for decomposition after thaw. A missing quality-depth trend shows that permafrost preserves the quality of ancient organic matter. When the organic matter is mobilized by deep degradation processes, the northern permafrost region may add up to 0.4°C to the global warming by the year 2300.}, language = {en} } @phdthesis{Wienhoefer2014, author = {Wienh{\"o}fer, Jan}, title = {On the role of structure-process interactions in controlling terrestrial systems : an exemplare of hillslope hydrology and a slow-moving landslide}, address = {Potsdam}, pages = {135 S.}, year = {2014}, language = {en} } @article{KoernerPfestorfMayetal.2014, author = {Koerner, Katrin and Pfestorf, Hans and May, Felix and Jeltsch, Florian}, title = {Modelling the effect of belowground herbivory on grassland diversity}, series = {Ecological modelling : international journal on ecological modelling and engineering and systems ecolog}, volume = {273}, journal = {Ecological modelling : international journal on ecological modelling and engineering and systems ecolog}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0304-3800}, doi = {10.1016/j.ecolmodel.2013.10.025}, pages = {79 -- 85}, year = {2014}, abstract = {One challenging question in ecology is to explain species coexistence in highly diverse temperate grassland plant communities. Within this context, a clear understanding of the consequences of belowground herbivory for the composition and the diversity of plant communities continue to elude ecologists. The existing body of empirical evidence reveals partly contradictory responses ranging from negative to neutral or positive effects of belowground herbivory on grassland diversity. To reveal possible mechanistic grounds for these discrepancies, we extended an existing simulation model of grassland communities based on plant functional types to include root herbivory. This enabled us to test the effects of different feeding modes that represent different herbivore guilds. For each belowground feeding mode, we systematically varied the intensity and frequency of herbivory events for three different levels of soil fertility both in the presence and absence of additional aboveground grazing. Our modelling approach successfully reproduced various empirically reported diversity responses, merely on the basis of the different feeding modes. Different levels of plant resource availability affected the strength, but not the direction of the belowground herbivory effects. The only exception was the scenario with low resource levels, which promoted neutral (neither positive nor negative) diversity responses for some of the feeding modes. Interestingly, aboveground biomass production was largely unaffected by diversity changes induced by belowground herbivory except in the case of selective feeding modes that were related to specific functional traits. Our findings provide possible explanations for the broad spectrum of belowground herbivory effects on plant community diversity. Furthermore, the presented theoretical modelling approach provides a suitable conceptual framework to better understand the complex linkage between plant community and belowground herbivory dynamics.}, language = {en} } @article{SchildgenYildirimCosentinoetal.2014, author = {Schildgen, Taylor F. and Yildirim, C. and Cosentino, Domenico and Strecker, Manfred}, title = {Linking slab break-off, Hellenic trench retreat, and uplift of the Central and Eastern Anatolian plateaus}, series = {Earth science reviews : the international geological journal bridging the gap between research articles and textbooks}, volume = {128}, journal = {Earth science reviews : the international geological journal bridging the gap between research articles and textbooks}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0012-8252}, doi = {10.1016/j.earscirev.2013.11.006}, pages = {147 -- 168}, year = {2014}, language = {en} } @phdthesis{Nguyen2014, author = {Nguyen, Van Manh}, title = {Large-scale floodplain sediment dynamics in the Mekong Delta : present state and future prospects}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-72512}, school = {Universit{\"a}t Potsdam}, pages = {ix, 95}, year = {2014}, abstract = {The Mekong Delta (MD) sustains the livelihood and food security of millions of people in Vietnam and Cambodia. It is known as the "rice bowl" of South East Asia and has one of the world's most productive fisheries. Sediment dynamics play a major role for the high productivity of agriculture and fishery in the delta. However, the MD is threatened by climate change, sea level rise and unsustainable development activities in the Mekong Basin. But despite its importance and the expected threats, the understanding of the present and future sediment dynamics in the MD is very limited. This is a consequence of its large extent, the intricate system of rivers, channels and floodplains and the scarcity of observations. Thus this thesis aimed at (1) the quantification of suspended sediment dynamics and associated sediment-nutrient deposition in floodplains of the MD, and (2) assessed the impacts of likely future boundary changes on the sediment dynamics in the MD. The applied methodology combines field experiments and numerical simulation to quantify and predict the sediment dynamics in the entire delta in a spatially explicit manner. The experimental part consists of a comprehensive procedure to monitor quantity and spatial variability of sediment and associated nutrient deposition for large and complex river floodplains, including an uncertainty analysis. The measurement campaign applied 450 sediment mat traps in 19 floodplains over the MD for a complete flood season. The data also supports quantification of nutrient deposition in floodplains based on laboratory analysis of nutrient fractions of trapped sedimentation.The main findings are that the distribution of grain size and nutrient fractions of suspended sediment are homogeneous over the Vietnamese floodplains. But the sediment deposition within and between ring dike floodplains shows very high spatial variability due to a high level of human inference. The experimental findings provide the essential data for setting up and calibration of a large-scale sediment transport model for the MD. For the simulation studies a large scale hydrodynamic model was developed in order to quantify large-scale floodplain sediment dynamics. The complex river-channel-floodplain system of the MD is described by a quasi-2D model linking a hydrodynamic and a cohesive sediment transport model. The floodplains are described as quasi-2D presentations linked to rivers and channels modeled in 1D by using control structures. The model setup, based on the experimental findings, ignored erosion and re-suspension processes due to a very high degree of human interference during the flood season. A two-stage calibration with six objective functions was developed in order to calibrate both the hydrodynamic and sediment transport modules. The objective functions include hydraulic and sediment transport parameters in main rivers, channels and floodplains. The model results show, for the first time, the tempo-spatial distribution of sediment and associated nutrient deposition rates in the whole MD. The patterns of sediment transport and deposition are quantified for different sub-systems. The main factors influencing spatial sediment dynamics are the network of rivers, channels and dike-rings, sluice gate operations, magnitude of the floods and tidal influences. The superposition of these factors leads to high spatial variability of the sediment transport and deposition, in particular in the Vietnamese floodplains. Depending on the flood magnitude, annual sediment loads reaching the coast vary from 48\% to 60\% of the sediment load at Kratie, the upper boundary of the MD. Deposited sediment varies from 19\% to 23\% of the annual load at Kratie in Cambodian floodplains, and from 1\% to 6\% in the compartmented and diked floodplains in Vietnam. Annual deposited nutrients (N, P, K), which are associated to the sediment deposition, provide on average more than 50\% of mineral fertilizers typically applied for rice crops in non-flooded ring dike compartments in Vietnam. This large-scale quantification provides a basis for estimating the benefits of the annual Mekong floods for agriculture and fishery, for assessing the impacts of future changes on the delta system, and further studies on coastal deposition/erosion. For the estimation of future prospects a sensitivity-based approach is applied to assess the response of floodplain hydraulics and sediment dynamics to the changes in the delta boundaries including hydropower development, climate change in the Mekong River Basin and effective sea level rise. The developed sediment model is used to simulate the mean sediment transport and sediment deposition in the whole delta system for the baseline (2000-2010) and future (2050-2060) periods. For each driver we derive a plausible range of future changes and discretize it into five levels, resulting in altogether 216 possible factor combinations. Our results thus cover all plausible future pathways of sediment dynamics in the delta based on current knowledge. The uncertainty of the range of the resulting impacts can be decreased in case more information on these drivers becomes available. Our results indicate that the hydropower development dominates the changes in sediment dynamics of the Mekong Delta, while sea level rise has the smallest effect. The floodplains of Vietnamese Mekong Delta are much more sensitive to the changes compared to the other subsystems of the delta. In terms of median changes of the three combined drivers, the inundation extent is predicted to increase slightly, but the overall floodplain sedimentation would be reduced by approximately 40\%, while the sediment load to the Sea would diminish to half of the current rates. These findings provide new and valuable information on the possible impacts of future development on the delta, and indicate the most vulnerable areas. Thus, the presented results are a significant contribution to the ongoing international discussion on the hydropower development in the Mekong basin and its impact on the Mekong delta.}, language = {en} }