Using RS and GIS to monitoring Beijing wetland resources evolution

In Beijing, Wetlands have been playing a crucial role in conserving municipal freshwater and retaining biodiversity. The classification system of Beijing wetland has been set up. The interpretation keys of six main wetland types in Beijing, including River, Reservoir, City Lake, Artificial Canal, Pound and Paddy Field, were built up using TM/ETM+ multi-spectral pseudo-color composition images as the data source. The modern information technology such as RS, GIS and GPS is combined with field investigation for further analysis to obtain the historical change information of wetland area, water quality and landscape pattern, The wetland soil and plant distribution maps in different large scale were sketched, and their attribute databases including hydrology, soil and plant were built up also. From which, its trend of evolution and some driving factors are analyzed successfully. This study indicates that not only have wetland areas been reduced by half, but also their ecological environments have been degraded because of rapid economic development and population increase. Suggestions based on this research are made to reconstruct the ecological environment of the wetlands and return them to their previous state.