Comprehensive assessments and zoning of ecological service functions for Beijing wetland based on RS and GIS

Abstract

The distribution,eco-service functions and the managements of wetlands especially for metropolis have a close relationship with the quality of eco-environments and city resident life.In this paper,a metropolis,Beijing,was selected as a typical study area,and the research activities were supported by the spatial information technologies such as remote sensing and GIS,and the multi-kinds of data such as remote sensing image data,survey data in fields and society statistics data were applied.According to the assessment framework of millennium ecosystem assessment(MA),a value evaluation method was used for constructing an assessment index system of wetland eco-services functions.For the requirements of assessment operations,the authors considered that the administrative districts and counties in Beijing could be taken as the assessing units.The analytic hierarchy process(AHP) method was applied to the weight calculation of each indicator.Then the comprehensive and quantitative indexes were defined and calculated at each assessing unit in the study area.The evaluation of Beijing wetlands ecological services included the adjustment functions,supply functions,culture functions,supporting functions and comprehensive functions.Through investigations,the distribution patterns of Beijing wetlands ecological services were summed up.Some conclusions have been reached: ① the regulating and provisioning functions of wetlands in Beijing are the most important,followed by the cultural function,and the supporting function plays a weaker role;② the order of the composite function intensity from highness to weakness in the whole assessment units is as follows: Miyun County takes the first place,the districts of Fangshan,Dongchen,Xichen,Chaoyang,Yanqing and Huairou possess the second importance,and the districts of Pinggu,Tongzhou,Haidian and Mentougou occupy the third place,whereas the other districts play the weakest role.