@article{BormanndeBritoCharchousietal.2018, author = {Bormann, Helge and de Brito, Mariana Madruga and Charchousi, Despoina and Chatzistratis, Dimitris and David, Amrei and Grosser, Paula Farina and Kebschull, Jenny and Konis, Alexandros and Koutalakis, Paschalis and Korali, Alkistis and Krauzig, Naomi and Meier, Jessica and Meliadou, Varvara and Meinhardt, Markus and Munnelly, Kieran and Stephan, Christiane and de Vos, Leon Frederik and Dietrich, J{\"o}rg and Tzoraki, Ourania}, title = {Impact of Hydrological Modellers' Decisions and Attitude on the Performance of a Calibrated Conceptual Catchment Model}, series = {Hydrology}, volume = {5}, journal = {Hydrology}, number = {4}, publisher = {MDPI}, address = {Basel}, issn = {2306-5338}, doi = {10.3390/hydrology5040064}, pages = {13}, year = {2018}, abstract = {In this study, 17 hydrologists with different experience in hydrological modelling applied the same conceptual catchment model (HBV) to a Greek catchment, using identical data and model code. Calibration was performed manually. Subsequently, the modellers were asked for their experience, their calibration strategy, and whether they enjoyed the exercise. The exercise revealed that there is considerable modellers' uncertainty even among the experienced modellers. It seemed to be equally important whether the modellers followed a good calibration strategy, and whether they enjoyed modelling. The exercise confirmed previous studies about the benefit of model ensembles: Different combinations of the simulation results (median, mean) outperformed the individual model simulations, while filtering the simulations even improved the quality of the model ensembles. Modellers' experience, decisions, and attitude, therefore, have an impact on the hydrological model application and should be considered as part of hydrological modelling uncertainty.}, language = {en} } @article{FriedrichWigantUngeretal.1995, author = {Friedrich, J{\"o}rg F. and Wigant, L. and Unger, Wolfgang E. S. and Lippitz, A. and Wittrich, H. and Prescher, Dietrich and Erdmann, J. and Gorsler, H.-V. and Nick, L.}, title = {Barrier properties of plasma-modified polypropylene and polyethylen eterephthalate}, year = {1995}, language = {en} } @article{PrescherFriedrichWigantetal.1995, author = {Prescher, Dietrich and Friedrich, J{\"o}rg F. and Wigant, L. and Unger, Wolfgang E. S. and Lippitz, A. and Wittrich, H. and Erdmann, J. and Gorsler, H.-V. and Nick, L.}, title = {Barrier properties of plasma-modified polypropylene and polyethylenether ephthalate}, year = {1995}, language = {en} } @article{PrescherFriedrichWigantetal.1995, author = {Prescher, Dietrich and Friedrich, J{\"o}rg F. and Wigant, L. and Unger, Wolfgang E. S. and Lippitz, H. and Erdmann, J. and Gorsler, H.-V. and Wittrich, H.}, title = {Barrier properties of plasma and chemically fluorinated polypropylene and polyethylene-terephthalate}, year = {1995}, language = {en} } @article{NatkhinSteidlDietrichetal.2012, author = {Natkhin, Marco and Steidl, J{\"o}rg and Dietrich, Ottfried and Dannowski, Ralf and Lischeid, Gunnar}, title = {Differentiating between climate effects and forest growth dynamics effects on decreasing groundwater recharge in a lowland region in Northeast Germany}, series = {Journal of hydrology}, volume = {448}, journal = {Journal of hydrology}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0022-1694}, doi = {10.1016/j.jhydrol.2012.05.005}, pages = {245 -- 254}, year = {2012}, abstract = {Declining groundwater levels in some forested regions in Northeast Germany indicate a reduction in groundwater recharge. Various interlinked aspects, such as changes in climate conditions and changes in forest structure, have been considered as the main factors affecting the regional level of groundwater recharge. For this study, the water balance model WaSiM-ETH was used to calculate groundwater recharge in a 104 km(2) area between 1958 and 2007. Climate impact analysis was driven by observed data from neighbouring meteorological stations. Changes in forest stands were reconstructed from the current status and literature studies. The model-based analysis showed that the average groundwater recharge under forest areas decreased from 1958 to 2007, with a trend of 2.3 mm/yr(2). The most important effect was changing climatic boundary conditions, which made up 53\% of the decrease. Declining precipitation is identified as the main factor. Changes in tree age distribution caused 18\% of the decrease, and the change of ground vegetation under pines (Pinus sylvestris) accounts for 29\%. In respect of the complexity and the interconnectivity of the processes of groundwater recharge, the necessity of using process-oriented distributed models such as WaSiM-ETH is discussed. We conclude that changes in forest stands affecting groundwater recharge could play a significant role in the water balance, especially in regions with a priori low total runoff, this has up to now often remained unquantified.}, 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{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} } @article{GliegeThomasSteidletal.2016, author = {Gliege, Steffen and Thomas, Bjoern D. 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}, series = {Water}, volume = {8}, journal = {Water}, publisher = {MDPI}, address = {Basel}, issn = {2073-4441}, doi = {10.3390/w8030102}, 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} } @article{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}, volume = {8}, journal = {Water}, publisher = {MDPI}, address = {Basel}, issn = {2073-4441}, doi = {10.3390/w8060252}, 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} } @article{ThomasLischeidSteidletal.2015, author = {Thomas, Bj{\"o}rn and Lischeid, Gunnar and Steidl, J{\"o}rg and Dietrich, Ottfried}, title = {Long term shift of low flows predictors in small lowland catchments of Northeast Germany}, series = {Journal of hydrology}, volume = {521}, journal = {Journal of hydrology}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0022-1694}, doi = {10.1016/j.jhydrol.2014.12.022}, pages = {508 -- 519}, year = {2015}, abstract = {Runoff, especially during summer months, and low flows have decreased in Central and Eastern Europe during the last decades. A detailed knowledge on predictors and dependencies between meteorological forcing, catchment properties and low flow is necessary to optimize regional adaption strategies to sustain minimum runoff. The objective of this study is to identify low flow predictors for 16 small catchments in Northeast Germany and their long-term shifts between 1965 and 2006. Non-linear regression models (support vector machine regression) were calibrated to iteratively select the most powerful low flow predictors regarding annual 30-day minimum flow (AM(30)). The data set consists of standardized precipitation (SPI) and potential evapotranspiration (SpETI) indices on different time scales and lag times. The potential evapotranspiration of the previous 48 and 3 months, as well as the precipitation of the previous 3 months and last year were the most relevant predictors for AM(30). Pearson correlation (r(2)) of the final model is 0.49 and if for every year the results for all catchments are averaged r(2) increases to 0.80 because extremes are smoothing out. Evapotranspiration was the most important low flow predictor for the study period. However, distinct long-term shifts in the predictive power of variables became apparent. The potential evapotranspiration of the previous 48 months explained most of the variance, but its relevance decreased during the last decades. The importance of precipitation variables increased with time. Model performance was higher at catchments with a more damped discharge behavior. The results indicate changes in the relevant processes or flow paths generating low flows. The identified predictors, temporal patterns and patterns between catchments will support the development of low flow monitoring systems and determine those catchments where adaption measures should aim more at increasing groundwater recharge. (C) 2014 Elsevier B.V. All rights reserved.}, language = {en} } @inproceedings{DeselOpelSiegerisetal.2023, author = {Desel, J{\"o}rg and Opel, Simone and Siegeris, Juliane and Draude, Claude and Weber, Gerhard and Schell, Timon and Schwill, Andreas and Thorbr{\"u}gge, Carsten and Sch{\"a}fer, Len Ole and Netzer, Cajus Marian and Gerstenberger, Dietrich and Winkelnkemper, Felix and Schulte, Carsten and B{\"o}ttcher, Axel and Thurner, Veronika and H{\"a}fner, Tanja and Ottinger, Sarah and Große-B{\"o}lting, Gregor and Scheppach, Lukas and M{\"u}hling, Andreas and Baberowski, David and Leonhardt, Thiemo and Rentsch, Susanne and Bergner, Nadine and Bonorden, Leif and Stemme, Jonas and Hoppe, Uwe and Weicker, Karsten and Bender, Esther and Barbas, Helena and Hamann, Fabian and Soll, Marcus and Sitzmann, Daniel}, title = {Hochschuldidaktik Informatik HDI 2021}, series = {Commentarii informaticae didacticae}, booktitle = {Commentarii informaticae didacticae}, number = {13}, editor = {Desel, J{\"o}rg and Opel, Simone and Siegeris, Juliane}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-548-4}, issn = {1868-0844}, doi = {10.25932/publishup-56507}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-565070}, pages = {299}, year = {2023}, abstract = {Die Fachtagungen HDI (Hochschuldidaktik Informatik) besch{\"a}ftigen sich mit den unterschiedlichen Aspekten informatischer Bildung im Hochschulbereich. Neben den allgemeinen Themen wie verschiedenen Lehr- und Lernformen, dem Einsatz von Informatiksystemen in der Hochschullehre oder Fragen der Gewinnung von geeigneten Studierenden, deren Kompetenzerwerb oder auch der Betreuung der Studierenden widmet sich die HDI immer auch einem Schwerpunktthema. Im Jahr 2021 war dies die Ber{\"u}cksichtigung von Diversit{\"a}t in der Lehre. Diskutiert wurden beispielsweise die Einbeziehung von besonderen fachlichen und {\"u}berfachlichen Kompetenzen Studierender, der Unterst{\"u}tzung von Durchl{\"a}ssigkeit aus nichtakademischen Berufen, aber auch die Gestaltung inklusiver Lehr- und Lernszenarios, Aspekte des Lebenslangen Lernens oder sich an die Diversit{\"a}t von Studierenden adaptierte oder adaptierende Lehrsysteme. Dieser Band enth{\"a}lt ausgew{\"a}hlte Beitr{\"a}ge der 9. Fachtagung 2021, die in besonderer Weise die Konferenz und die dort diskutierten Themen repr{\"a}sentieren.}, language = {de} } @article{KamjunkeBeckersHerzsprungetal.2022, author = {Kamjunke, Norbert and Beckers, Liza-Marie and Herzsprung, Peter and von T{\"u}mpling, Wolf and Lechtenfeld, Oliver and Tittel, J{\"o}rg and Risse-Buhl, Ute and Rode, Michael and Wachholz, Alexander and Kallies, Rene and Schulze, Tobias and Krauss, Martin and Brack, Werner and Comero, Sara and Gawlik, Bernd Manfred and Skejo, Hello and Tavazzi, Simona and Mariani, Giulio and Borchardt, Dietrich and Weitere, Markus}, title = {Lagrangian profiles of riverine autotrophy, organic matter transformation, and micropollutants at extreme drought}, series = {The science of the total environment : an international journal for scientific research into the environment and its relationship with man}, volume = {828}, journal = {The science of the total environment : an international journal for scientific research into the environment and its relationship with man}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0048-9697}, doi = {10.1016/j.scitotenv.2022.154243}, pages = {14}, year = {2022}, abstract = {On their way from inland to the ocean, flowing water bodies, their constituents and their biotic communities are ex-posed to complex transport and transformation processes. However, detailed process knowledge as revealed by La-grangian measurements adjusted to travel time is rare in large rivers, in particular at hydrological extremes. To fill this gap, we investigated autotrophic processes, heterotrophic carbon utilization, and micropollutant concentrations applying a Lagrangian sampling design in a 600 km section of the River Elbe (Germany) at historically low discharge. Under base flow conditions, we expect the maximum intensity of instream processes and of point source impacts. Phy-toplankton biomass and photosynthesis increased from upstream to downstream sites but maximum chlorophyll con-centration was lower than at mean discharge. Concentrations of dissolved macronutrients decreased to almost complete phosphate depletion and low nitrate values. The longitudinal increase of bacterial abundance and production was less pronounced than in wetter years and bacterial community composition changed downstream. Molecular analyses revealed a longitudinal increase of many DOM components due to microbial production, whereas saturated lipid-like DOM, unsaturated aromatics and polyphenols, and some CHOS surfactants declined. In decomposition exper-iments, DOM components with high O/C ratios and high masses decreased whereas those with low O/C ratios, low masses, and high nitrogen content increased at all sites. Radiocarbon age analyses showed that DOC was relatively old (890-1870 years B.P.), whereas the mineralized fraction was much younger suggesting predominant oxidation of algal lysis products and exudates particularly at downstream sites. Micropollutants determining toxicity for algae (terbuthylazine, terbutryn, isoproturon and lenacil), hexachlorocyclohexanes and DDTs showed higher concentrations from the middle towards the downstream part but calculated toxicity was not negatively correlated to phytoplankton. Overall, autotrophic and heterotrophic process rates and micropollutant concentrations increased from up-to down-stream reaches, but their magnitudes were not distinctly different to conditions at medium discharges.}, language = {en} } @article{JannBogumilBouckaertetal.2004, author = {Jann, Werner and Bogumil, J{\"o}rg and Bouckaert, Geert and Bud{\"a}us, Dietrich and Holtkamp, Lars and Kißler, Leo and Kuhlmann, Sabine and Mezger, Erika and Reichard, Christoph and Wollmann, Hellmut}, title = {Status-Report Verwaltungsreform : eine Zwischenbilanz nach zehn Jahren}, series = {Modernisierung des {\"o}ffentlichen Sektors}, volume = {24}, journal = {Modernisierung des {\"o}ffentlichen Sektors}, publisher = {Ed. Sigma}, address = {Berlin}, isbn = {3-89404-744-5}, pages = {122 S.}, year = {2004}, language = {de} } @article{KamaliJahanbakhshiDogaruetal.2022, author = {Kamali, Bahareh and Jahanbakhshi, Farshid and Dogaru, Diana and Dietrich, J{\"o}rg and Nendel, Claas and AghaKouchak, Amir}, title = {Probabilistic modeling of crop-yield loss risk under drought: a spatial showcase for sub-Saharan Africa}, series = {Environmental research letters}, volume = {17}, journal = {Environmental research letters}, number = {2}, publisher = {IOP Publishing}, address = {Bristol}, issn = {1748-9326}, doi = {10.1088/1748-9326/ac4ec1}, pages = {15}, year = {2022}, abstract = {Assessing the risk of yield loss in African drought-affected regions is key to identify feasible solutions for stable crop production. Recent studies have demonstrated that Copula-based probabilistic methods are well suited for such assessment owing to reasonably inferring important properties in terms of exceedance probability and joint dependence of different characterization. However, insufficient attention has been given to quantifying the probability of yield loss and determining the contribution of climatic factors. This study applies the Copula theory to describe the dependence between drought and crop yield anomalies for rainfed maize, millet, and sorghum crops in sub-Saharan Africa (SSA). The environmental policy integrated climate model, calibrated with Food and Agriculture Organization country-level yield data, was used to simulate yields across SSA (1980-2012). The results showed that the severity of yield loss due to drought had a higher magnitude than the severity of drought itself. Sensitivity analysis to identify factors contributing to drought and high-temperature stresses for all crops showed that the amount of precipitation during vegetation and grain filling was the main driver of crop yield loss, and the effect of temperature was stronger for sorghum than for maize and millet. The results demonstrate the added value of probabilistic methods for drought-impact assessment. For future studies, we recommend looking into factors influencing drought and high-temperature stresses as individual/concurrent climatic extremes.}, language = {en} }