WebGIS-based approach to simulate water and solute fluxes in the Miyun basin in China

Abstract

The Miyun reservoir, located approximately 100 km North-East of the Beijing municipality, is one of the main surface water supply sources for the 20 million people living in this metropolitan area. For a variety of anthropogenic and natural reasons the Miyun reservoir suffers from increasing water quantity and quality problems. Over the past 20 years the reservoir water level has declined by 10 m and the water quality status is classified as "mesotrophic" with a tendency to "eutrophic". This means the water does not fulfil the requirements for use as drinking water. This book chapter describes the bottom-up research strategy for monitoring and modelling water and solute fluxes in the catchment as a basic precondition to establish sustainable management strategies. It focuses on the connection of hydrological investigations from plot to field via sub-catchment scale and meso-scale modelling in the Miyun catchment area with the STOFFBILANZ model. It is demonstrated how this model was adapted to the natural conditions of Northern China. Based on practical examples of land use change strategies and improvement of wastewater treatment the use of the model to calculate different scenarios to reduce non-point and point source pollution in the Miyun catchment area will be shown.