A hybrid GIS-supported watershed modelling system: application to the LakeErhai basin, China

In this study, a hybrid GIS-supported watershed modelling system is develop ed for integrated planning of water pollution control in the Lake Erhai bas in, China. The system comprises a GIS-supported database, simulation/optimi zation models, and user interfaces developed through Arc/Info and ArcView. An inexact-fuzzy multi-objective optimization model is developed for assess ing a variety of system objectives and generating desired decision alternat ives. It can effectively reflect uncertain, interactive and multi-objective features of the study system, and its solutions provide decision makers wi th a flexible decision space. The GIS technology is used for managing spati al and non-spatial data, linking models, and providing interfaces between t he models and their users. The developed modelling system allows regional p lanners to obtain desired plans of human activities under a variety of obje ctives and constraints and to examine consequences and impacts resulting fr om alternative management practices.