Das Projekt "Submarine Groundwater-Fluxes and Transport-Processes from Methane Rich Coastal Sedimentary Environments (Sub-GATE) - Task 8: Groundwater flow modelling" wird vom Umweltbundesamt gefördert und von Universität Stuttgart, Institut für Wasserbau durchgeführt. The goal of the project is to establish a 2D and a 3D groundwater flow model at the transition of subterranean-submarine hydrological regime of proposed seepage systems. To achieve this the enhancement of the numerical formulation and solution procedure of the sharp interface modeling approach for multilayered aquifer systems is necessary. These enhancements include an improved choice of the dependent variables to yield a more robust conservative numerical approximation, less restrictive vertical leakage calculation, rigorous treatment of well conditions, full Newton-Raphson treatment of nonlinearities, and the use of an efficient solver technique (UG, see BASTIAN, 1993). The approach is based on the multiphase flow, transport and energy model (MUFTE, see HELMIG et al., 1994). The necessary steps are: 1. Simulating the submarine groundwater discharge at the outflow of a vent and a seep area by a two dimensional flow and transport model (MUFTE UG). Different characteristic hydrological and submarine flow regimes of the examined area will be studied with the purpose to predict the order of magnitude of water and (non-reactive) mass fluxes at the vent and seep sites. By adjusting the model in order to approximate the representative hydraulic and chemical parameters, the main mechanisms which are controlling the submarine groundwater discharge will be analyzed. 2. Based on these studies of the subterranean-submarine flow regime a numerical model will be established and calibrated for the prediction of the water and mass fluxes in different subdomaines of the area of interest.