Modelling of hydrological and hydrochemical variability under enviromental change impact

Climate change inducing significant variations in the seasonal dynamics of the water cycle and hydrological extremes and land use change as one of the anthropogenic effects are among the major driving forces of global environmental change. Large and meso-scale river basins represent an appropnate unit to study global change impacts on water quality and quantity at the regional scale and to estimate water, material, and biogeochemical budgets. The Elbe nver basin is used as test region for the application of the Nested Watershed Approach based on the Two-Domains-Modelling-Concept to test, modify, and validate models, pararnetrization schemes, and up- and downscaling techniques. In order to achieve the objectives of the project a Hydrological Modular Simulation System for catchment basin studies is developed, based on a Geographical Information System (GIS) and the Modular Modelling System (MMS). Within this system a number of hydrological and hydrochemical simulation models and model components are tested and modified with special attention to regional approaches for the analysis and modelling of hydrological, biogeochemical, and hydrochemical processes