Coupled surface and groundwater modeling for the analysis of management options in groundwater affected catchment areas

In this project a water management concept for the southern Randowbruch is developed, which meets the climate protection goals according to the Climate Protection Plan 2050 of the German Ministry of Environment regarding a comprehensive moor protection in the Randowbruch. The paper forms the basis for the realization of a management concept and deals in particular with the analysis of the special characteristics of the catchment area and the possible management options with the current management system. The catchment area of the Randow has a long and highly anthropogenic influenced history of melioration. The moor, which formed during the Vistula Ice Age around 18,000 years ago in the washout channel of a glacier, has been continuously drained and made agriculturally usable throughout the past 300 years by targeted human interventions. The moor was drained by ditches installed along the original main receiving water, the Randow, and dams to control water levels for agricultural use. The draining measures reached their peak in the 60s and 70s of the 20th century and have remained unchanged since. Taking into account the intensive interaction between groundwater and surface water in this area, the analysis of this catchment with a hydrological model is only possibly by including this interaction. The primary process of this interaction is the exfiltration of groundwater into the system of ditches, as well as the infiltration of water back into the groundwater. Thus, the evaporation and in particular the water levels of areas with high levels of groundwater and the adjacent ditches represent the essential boundary conditions for the exchange of the two hydrological units. Therefore, the basis for the development of the management concept is a coupled model of ArcEGMO and FEFLOW, with FEFLOW modeling the groundwater flow and ArcEGMO simulating the hydrologic balance and the complex system of water bodies. 

Keywords: 

coupled modeling, ArcEGMO, FELFOW, water resource management, moor protection