@article{SinghSinhaMishraetal.2022, author = {Singh, Manudeo and Sinha, Rajiv and Mishra, Arjit and Babu, Suresh}, title = {Wetlandscape (dis)connectivity and fragmentation in a large wetland (Haiderpur) in west Ganga plains, India}, series = {Earth surface processes and landforms : the journal of the British Geomorphological Research Group}, volume = {47}, journal = {Earth surface processes and landforms : the journal of the British Geomorphological Research Group}, number = {7}, publisher = {Wiley}, address = {New York, NY [u.a.]}, issn = {0197-9337}, doi = {10.1002/esp.5352}, pages = {1872 -- 1887}, year = {2022}, abstract = {Wetlands are dynamic ecosystems that require continuous monitoring and assessment of degradation status to design strategies for their sustainable management. While hydrology provides the primary functional control for the wetland ecosystem, the loss of landscape connectivity influences wetland degradation in a major way as it leads to fragmentation. This article aims to integrate hydrogeomorphic and ecological concepts for the assessment of degradation status and its causal factors for a large wetland in the western Ganga plains, India, the Haiderpur, using a wetlandscape approach. We have used a remote-sensing-based approach, which offers a powerful tool for assessing and linking cross-scale structures, functions, and controls in a wetlandscape. The Haiderpur, a Ramsar site since December 2021, is an artificial wetland located on the right bank of the Ganga River wherein the inflows are controlled by a barrage constructed on the Ganga River apart from smaller tributaries flowing in from the north. A novel aspect of this work is the integration of river dynamics and its connectivity to the wetlandscape to understand the spatiotemporal variability in the waterspread area in the wetland. In this work, we have developed an integrated wetlandscape assessment approach by evaluating wetland's geomorphic and hydrological connectivity status for the period 1993-2019 (25 years) across three different spatial scales - regional, catchment, and wetland. We have highlighted the ecological implications of connectivity and patch dynamics for developing sustainable wetland management plans.}, language = {en} } @article{FahleDietrichLischeid2013, author = {Fahle, Marcus and Dietrich, Ottfried and Lischeid, Gunnar}, title = {A guideline for developing an initial hydrological monotoring network as a basis for water management in artificially drained wetlands}, series = {Irrigation and drainage}, volume = {62}, journal = {Irrigation and drainage}, number = {4}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {1531-0353}, doi = {10.1002/ird.1744}, pages = {524 -- 536}, year = {2013}, abstract = {Reliable hydrological monitoring is the basis for sound water management in drained wetlands. Since statistical methods cannot be employed for unobserved or sparsely monitored areas, the primary design (first set-up) may be arbitrary in most instances. The objective of this paper is therefore to provide a guideline for designing the initial hydrological monitoring network. A scheme is developed that handles different parts of monitoring and hydrometry in wetlands, focusing on the positioning of surface water and groundwater gauges. For placement of the former, control units are used which correspond to areas whose water levels can be regulated separately. The latter are arranged depending on hydrological response units, defined by combinations of soil type and land use, and the chosen surface water monitoring sites. A practical application of the approach is shown for an investigation area in the Spreewald region in north-east Germany. The presented scheme leaves a certain degree of freedom to its user, allowing the inclusion of expert knowledge or special concerns. Based on easily obtainable data, the developed hydrological network serves as a first step in the iterative procedure of monitoring network optimisation. Copyright (c) 2013 John Wiley \& Sons, Ltd.}, language = {en} } @article{FahleDietrich2014, author = {Fahle, Marcus and Dietrich, Ottfried}, title = {Estimation of evapotranspiration using diurnal groundwater level fluctuations: Comparison of different approaches with groundwater lysimeter data}, series = {Water resources research}, volume = {50}, journal = {Water resources research}, number = {1}, publisher = {American Geophysical Union}, address = {Washington}, issn = {0043-1397}, doi = {10.1002/2013WR014472}, pages = {273 -- 286}, year = {2014}, abstract = {In wetlands or riparian areas, water withdrawal by plants with access to groundwater or the capillary fringe often causes diurnal groundwater fluctuations. Various approaches use the characteristics of these fluctuations for estimation of daily groundwater evapotranspiration rates. The objective of this paper was to review the available methods, compare them with measured evapotranspiration and assess their recharge assumptions. For this purpose, we employed data of 85 rain-free days of a weighable groundwater lysimeter situated at a grassland site in the Spreewald wetland in north-east Germany. Measurements of hourly recharge and daily evapotranspiration rates were used to assess the different approaches. Our results showed that a maximum of 50\% of the day to day variance of the daily evapotranspiration rates could be explained by the approaches based on groundwater fluctuations. Simple and more complex methods performed similarly. For some of the approaches, there were indications that erroneous assumptions compensated each other (e.g., when overestimated recharge counteracted underestimated storage change). We found that the usage of longer time spans resulted in improved estimates of the daily recharge rates and that the estimates were further enhanced by including two night averages. When derived from fitting estimates of recharge or evapotranspiration with according measurements the specific yield, needed to convert changes in water level to water volumes, differed considerably among the methods (from 0.022 to 0.064). Thus, the specific yield can be seen as correction factor that compensates for inadequate process descriptions.}, 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{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} }