Interfacing Gis with a Process Based Agro-ecosystem Model –case Study North China Plain

The Sino-German Project between the China Agricultural University and the University of Hohenheim, Germany, focused on sustainable Agriculture in the North China Plain. One major focus of the project was the establishment of an experiment field near Beijing to investigate different agricultural practices and their impact on yield and environment. The second task was to set-up a GIS based Agricultural Environmental Information System (AEIS) for the North China Plain (NCP), which exceeds almost the size of Germany. Researchers from several departments are involved in the project: Agricultural Economics, Agricultural Informatics, Vegetable Science, Landscape Ecology, Phytomedicine, Plant Nutrition, Plant Production and Soil Science. The major aim of the AEIS for the NCP is to provide information (i) about agriculture in the region, (ii) about the impact of agricultural practices on the environment and (iii) of simulation scenarios for sustainable strategies. Consequently, the AEIS for the NCP provides information for decision support and therefore could be regarded as a Decision Support System (DSS), too. In this contribution, the focus is on the importance of the linkage of process-based agro-ecosystem models, here the DNDC model with GIS. The purpose of the linkage is the modeling of agro-environmental impacts on a regional level. Due to the geographic extent of the North China Plain, it could be regarded as national level as well. A key issue in the GIS-based regional modeling is the establishment of an adequate geodatabase which here is defined as a Agricultural Environmental Information System (AEIS). By using the database of the AEIS, it is possible in this case study to model with a process-based model the emission of N2O, the volatilization of NH3, and the leaching of NO3 from winter wheat/summer maize area for the entire North China Plain. Finally, the comparison with and evaluation of available models and methods (IPCC; SLUSA) for regional calculation is presented.