@phdthesis{He2011, author = {He, Ling}, title = {Wanderarbeiter in Peking : Soziale, {\"o}konomische und r{\"a}umliche Aspekte eines aktuellen Migrationsproblems in China}, address = {Potsdam}, pages = {220 S.}, year = {2011}, language = {de} } @phdthesis{Engemaier2011, author = {Engemaier, Rita}, title = {Webbasierte kartografische Visualisierung : theoretisch-methodische Grundlegung und Ableitung eines Konzeptes zur Erzeugung von Qualit{\"a}tskarten auf Basis von Webservices}, address = {Potsdam}, pages = {111 S.}, year = {2011}, language = {de} } @phdthesis{Mueller2011, author = {M{\"u}ller, Kristine}, title = {Alltag im Abseits : Handlungsorientierungen {\"o}konomischer Akteure an der {\"o}stlichen Außengrenze der Europ{\"a}ischen Union}, address = {Potsdam}, pages = {219 S.}, year = {2011}, language = {de} } @article{ReusserZehe2011, author = {Reusser, Dominik Edwin and Zehe, Erwin}, title = {Low-cost monitoring of snow height and thermal properties with inexpensive temperature sensors}, series = {Hydrological processes}, volume = {25}, journal = {Hydrological processes}, number = {12}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0885-6087}, doi = {10.1002/hyp.7937}, pages = {1841 -- 1852}, year = {2011}, abstract = {Small, self-recording temperature sensors were installed at several heights along a metal rod at five locations in a case study catchment. For each sensor, the presence or absence of snow cover was determined on the basis of its insulating effect and the resulting reduction of the diurnal temperature oscillations. Sensor coverage was then converted into a time series of snow height for each location. Additionally, cold content was calculated. Snow height and cold content provide valuable information for spring flood prediction. Good agreement of estimated snow heights with reference measurements was achieved and increased discharge in the study catchment coincided with low cold content of the snow cover. The results of the proposed distributed assessment of snow cover and snow state show great potential for (i) flood warning, (ii) assimilation of snow state data and (iii) modelling snowmelt process.}, language = {en} } @article{ReusserZehe2011, author = {Reusser, Dominik Edwin and Zehe, Erwin}, title = {Inferring model structural deficits by analyzing temporal dynamics of model performance and parameter sensitivity}, series = {Water resources research}, volume = {47}, journal = {Water resources research}, publisher = {American Geophysical Union}, address = {Washington}, issn = {0043-1397}, doi = {10.1029/2010WR009946}, pages = {15}, year = {2011}, abstract = {In this paper we investigate the use of hydrological models as learning tools to help improve our understanding of the hydrological functioning of a catchment. With the model as a hypothetical conceptualization of how dominant hydrological processes contribute to catchment-scale response, we investigate three questions: (1) During which periods does the model (not) reproduce observed quantities and dynamics? (2) What is the nature of the error during times of bad model performance? (3) Which model components are responsible for this error? To investigate these questions, we combine a method for detecting repeating patterns of typical differences between model and observations (time series of grouped errors, TIGER) with a method for identifying the active model components during each simulation time step based on parameter sensitivity (temporal dynamics of parameter sensitivities, TEDPAS). The approach generates a time series of occurrence of dominant error types and time series of parameter sensitivities. A synoptic discussion of these time series highlights deficiencies in the assumptions about the functioning of the catchment. The approach is demonstrated for the Weisseritz headwater catchment in the eastern Ore Mountains. Our results indicate that the WaSiM-ETH complex grid-based model is not a sufficient working hypothesis for the functioning of the Weisseritz catchment and point toward future steps that can help improve our understanding of the catchment.}, language = {en} } @article{ReusserBuytaertZehe2011, author = {Reusser, Dominik Edwin and Buytaert, W. and Zehe, Erwin}, title = {Temporal dynamics of model parameter sensitivity for computationally expensive models with the Fourier amplitude sensitivity test}, series = {Water resources research}, volume = {47}, journal = {Water resources research}, number = {4}, publisher = {American Geophysical Union}, address = {Washington}, issn = {0043-1397}, doi = {10.1029/2010WR009947}, pages = {14}, year = {2011}, abstract = {The quest for improved hydrological models is one of the big challenges in hydrology. When discrepancies are observed between simulated and measured discharge, it is essential to identify which algorithms may be responsible for poor model behavior. Particularly in complex hydrological models, different process representations may dominate at different moments and interact with each other, thus highly complicating this task. This paper investigates the analysis of the temporal dynamics of parameter sensitivity as a way to disentangle the simulation of a hydrological model and identify dominant parameterizations. Three existing methods (the Fourier amplitude sensitivity test, the extended Fourier amplitude sensitivity test, and Sobol's method) are compared by applying them to a TOPMODEL implementation in a small mountainous catchment in the tropics. For the major part of the simulation period, the three methods give comparable results, while the Fourier amplitude sensitivity test is much more computationally efficient. This method is also applied to the complex hydrological model WaSiM-ETH implemented in the Weisseritz catchment, Germany. A qualitative model validation was performed on the basis of the identification of relevant model components. The validation revealed that the saturation deficit parameterization of WaSiM-ETH is highly susceptible to parameter interaction and lack of identifiability. We conclude that temporal dynamics of model parameter sensitivity can be a powerful tool for hydrological model analysis, especially to identify parameter interaction as well as the dominant hydrological response modes. Finally, an open source implementation of the Fourier amplitude sensitivity test is provided.}, language = {en} } @article{HasslerLarkMilneetal.2011, author = {Haßler, Sibylle Kathrin and Lark, Richard M. and Milne, A. E. and Elsenbeer, Helmut}, title = {Exploring the variation in soil saturated hydraulic conductivity under a tropical rainforest using the wavelet transform}, series = {European journal of soil science}, volume = {62}, journal = {European journal of soil science}, number = {6}, publisher = {Wiley-Blackwell}, address = {Malden}, issn = {1351-0754}, doi = {10.1111/j.1365-2389.2011.01400.x}, pages = {891 -- 901}, year = {2011}, abstract = {Saturated hydraulic conductivity (Ks) of the soil is a key variable in the water cycle. For the humid tropics, information about spatial scales of Ks and their relation to soil types deduced from soil map units is of interest, as soil maps are often the only available data source for modelling. We examined the influence of soil map units on the mean and variation in Ks along a transect in a tropical rainforest using undisturbed soil cores at 06 and 612 cm depth. The Ks means were estimated with a linear mixed model fitted by residual maximum likelihood (REML), and the spatial variation in Ks was investigated with the maximum overlap discrete wavelet packet transform (MODWPT). The mean values of Ks did not differ between soil map units. The best wavelet packet basis for Ks at 06 cm showed stationarity at high frequencies, suggesting uniform small-scale influences such as bioturbation. There were substantial contributions to wavelet packet variance over the range of spatial frequencies and a pronounced low frequency peak corresponding approximately to the scale of soil map units. However, in the relevant frequency intervals no significant changes in wavelet packet variance were detected. We conclude that near-surface Ks is not dominated by static, soil-inherent properties for the examined range of soils. Several indicators from the wavelet packet analysis hint at the more dominant dynamic influence of biotic processes, which should be kept in mind when modelling soil hydraulic properties on the basis of soil maps.}, language = {en} } @article{KaiserWalterEllerbrocketal.2011, author = {Kaiser, Michael and Walter, K. and Ellerbrock, Ruth H. and Sommer, Michael}, title = {Effects of land use and mineral characteristics on the organic carbon content, and the amount and composition of Na-pyrophosphate-soluble organic matter, in subsurface soils}, series = {European journal of soil science}, volume = {62}, journal = {European journal of soil science}, number = {2}, publisher = {Wiley-Blackwell}, address = {Malden}, issn = {1351-0754}, doi = {10.1111/j.1365-2389.2010.01340.x}, pages = {226 -- 236}, year = {2011}, abstract = {Land use and mineral characteristics affect the ability of surface as well as subsurface soils to sequester organic carbon and their contribution to mitigation of the greenhouse effect. There is less information about the effects of land use and soil properties on the amount and composition of organic matter (OM) for subsurface soils as compared with surface soils. Here we aimed to analyse the long-term (>= 100 years) impact of arable and forest land use and soil mineral characteristics on subsurface soil organic carbon (SOC) contents, as well as on amount and composition of OM sequentially separated by Na pyrophosphate solution (OM(PY)) from subsurface soil samples. Seven soils with different mineral characteristics (Albic and Haplic Luvisol, Colluvic and Haplic Regosol, Haplic and Vertic Cambisol, Haplic Stagnosol) were selected from within Germany. Soil samples were taken from subsurface horizons of forest and adjacent arable sites continuously used for > 100 years. The OM(PY) fractions were analysed for their OC content (OC(PY)) and characterized by Fourier transform infrared spectroscopy. Multiple regression analyses for the arable subsurface soils indicated significant positive relationships between the SOC contents and combined effects of the (i) exchangeable Ca (Ca(ex)) and oxalate-soluble Fe (Fe(ox)) and (ii) the Ca(ex) and Al(ox) contents. For these soils the increase in OC (OC(PY) multiplied by the relative C=O content of OM(PY)) and increasing contents of Ca(ex) indicated that OM(PY) mainly interacts with Ca2+. For the forest subsurface soils (pH < 5), the OC(PY) contents were related to the contents of Na-pyrophosphate-soluble Fe and Al. The long-term arable and forest land use seems to result in different OM(PY)-mineral interactions in subsurface soils. On the basis of this, we hypothesize that a long-term land-use change from arable to forest may lead to a shift from mainly OM(PY)-Ca2+ to mainly OM(PY)-Fe3+ and -Al3+ interactions if the pH of subsurface soils significantly decreases to < 5.}, language = {en} } @article{NeillChavesBiggsetal.2011, author = {Neill, Christopher and Chaves, Joaqu{\´i}n E. and Biggs, Trent and Deegan, Linda A. and Elsenbeer, Helmut and Figueiredo, Ricardo O. and Germer, Sonja and Johnson, Mark S. and Lehmann, Johannes and Markewitz, Daniel and Piccolo, Marisa C.}, title = {Runoff sources and land cover change in the Amazon an end-member mixing analysis from small watersheds}, series = {Biogeochemistry}, volume = {105}, journal = {Biogeochemistry}, number = {1-3}, publisher = {Springer}, address = {Dordrecht}, issn = {0168-2563}, doi = {10.1007/s10533-011-9597-8}, pages = {7 -- 18}, year = {2011}, abstract = {The flowpaths by which water moves from watersheds to streams has important consequences for the runoff dynamics and biogeochemistry of surface waters in the Amazon Basin. The clearing of Amazon forest to cattle pasture has the potential to change runoff sources to streams by shifting runoff to more surficial flow pathways. We applied end-member mixing analysis (EMMA) to 10 small watersheds throughout the Amazon in which solute composition of streamwater and groundwater, overland flow, soil solution, throughfall and rainwater were measured, largely as part of the Large-Scale Biosphere-Atmosphere Experiment in Amazonia. We found a range in the extent to which streamwater samples fell within the mixing space determined by potential flowpath end-members, suggesting that some water sources to streams were not sampled. The contribution of overland flow as a source of stream flow was greater in pasture watersheds than in forest watersheds of comparable size. Increases in overland flow contribution to pasture streams ranged in some cases from 0\% in forest to 27-28\% in pasture and were broadly consistent with results from hydrometric sampling of Amazon forest and pasture watersheds that indicate 17- to 18-fold increase in the overland flow contribution to stream flow in pastures. In forest, overland flow was an important contribution to stream flow (45-57\%) in ephemeral streams where flows were dominated by stormflow. Overland flow contribution to stream flow decreased in importance with increasing watershed area, from 21 to 57\% in forest and 60-89\% in pasture watersheds of less than 10 ha to 0\% in forest and 27-28\% in pastures in watersheds greater than 100 ha. Soil solution contributions to stream flow were similar across watershed area and groundwater inputs generally increased in proportion to decreases in overland flow. Application of EMMA across multiple watersheds indicated patterns across gradients of stream size and land cover that were consistent with patterns determined by detailed hydrometric sampling.}, language = {en} } @article{ParisiPaternosterKohfahletal.2011, author = {Parisi, Serena and Paternoster, Michele and Kohfahl, Claus and Pekdeger, Asaf and Meyer, Hanno and Hubberten, Hans-Wolfgang and Spilotro, Giuseppe and Mongelli, Giovanni}, title = {Groundwater recharge areas of a volcanic aquifer system inferred from hydraulic, hydrogeochemical and stable isotope data mount Vulture, southern Italy}, series = {Hydrogeology journal : official journal of the International Association of Hydrogeologists}, volume = {19}, journal = {Hydrogeology journal : official journal of the International Association of Hydrogeologists}, number = {1}, publisher = {Springer}, address = {New York}, issn = {1431-2174}, doi = {10.1007/s10040-010-0619-8}, pages = {133 -- 153}, year = {2011}, abstract = {Environmental isotope techniques, hydrogeochemical analysis and hydraulic data are employed to identify the main recharge areas of the Mt. Vulture hydrogeological basin, one of the most important aquifers of southern Italy. The groundwaters are derived from seepage of rainwater, flowing from the highest to the lowest elevations through the shallow volcanic weathered host-rock fracture zones. Samples of shallow and deep groundwater were collected at 48 locations with elevations ranging from 352 to 1,100 m above sea level (a.s.l.), for stable isotope (delta(18)O, delta D) and major ion analyses. A complete dataset of available hydraulic information has been integrated with measurements carried out in the present study. Inferred recharge elevations, estimated on the basis of the local vertical isotopic gradient of delta(18)O, range between 550 and 1,200 m a.s.l. The isotope pattern of the Quaternary aquifer reflects the spatial separation of different recharge sources. Knowledge of the local hydrogeological setting was the starting point for a detailed hydrogeochemical and isotopic study to define the recharge and discharge patterns identifying the groundwater flow pathways of the Mt. Vulture basin. The integration of all the data allowed for the tracing of the groundwater flows of the Mt. Vulture basin.}, language = {en} } @article{NadavanRensburgClaassensetal.2011, author = {Nada, Wael M. and van Rensburg, Leon and Claassens, Sarina and Blumenstein, Oswald}, title = {Effect of vermicompost on soil and plant properties of coal spoil in the Lusatian Region (Eastern Germany)}, series = {Communications in soil science and plant analysis}, volume = {42}, journal = {Communications in soil science and plant analysis}, number = {16}, publisher = {Taylor \& Francis Group}, address = {Philadelphia}, issn = {0010-3624}, doi = {10.1080/00103624.2011.591469}, pages = {1945 -- 1957}, year = {2011}, abstract = {This study was conducted to evaluate the effect of different wood vermicompost application rates on some soil physical and chemical properties as well as on growth parameters of a grass seed mixture (RSM 7.2.1) in tertiary sand contaminated with coal spoil. The experiment was carried out in a greenhouse over a period of 42 days. Soil was mixed with vermicompost at ratios of 0.0, 3.0, 12.5, and 25.0\% and sown with the grass seed mixture. Soil samples and plant material were analyzed to determine the effect of different vermicompost application rates on the physical and chemical properties. Results revealed that the physical and chemical properties of the soil improved with increasing application rates of vermicompost. In addition, soil treated with vermicompost showed significant increases in fresh-and dry-matter yields of the grass, as well as enhanced uptake of nutrients by the grass. This indicated that treatment of contaminated soils with vermicompost may be beneficial for reclamation processes by facilitating revegetation of disturbed areas.}, language = {en} }