Being located in the northwest of Beijing, Guanting Reservoir has been an important source to supply water for life, production and landscape; however, with the increasing urbanization and population agglomeration in the upstream since 1980s, the resource and environment of Guanting Reservoir Basin was also undertaken an increasingly pressure accordingly with water quantity dropped and quality deteriorated, so Guanting Reservoir was ruled out of the drinking water supply system of Beijing since 1997. As a series of ecological protection and management project have been implemented with the 21st century coming, Guanting Reservoir restored its water-supply function for agriculture, ecology and industry in 2003, and restored its function as drinking water source in 2007, so it became an emergency water-supply source of Beijing again. The environmental protection status and economic development model of Guanting Reservoir Basin plays an essential role for water security of Beijing. In this paper, taken Guanting Reservoir Basin as the study case, the land use data of different periods since 1980s have been extracted from remote sensing images of the study area to analyze the land use changes. Based on the land use data, Costanza ecosystem service value formula and correction parameter suitable for China situations, the basin ecosystem service value is calculated to analyze the changes in leading ecosystem function of Guanting Reservoir Basin in different periods. In combination with the social and economic statistical data, the driving factors are discussed for changes in the leading function, and the approaches are put forward to enhance the upstream ecosystem function, so as to guarantee the sustainable economic and social development in the Basin. It is indicated from the research results that: (1) the driving forces for the changes in dominate ecosystem functions of Guanting Reservoir Basin mainly result from policy factor, population factor and economic factor; (2) the ecosystem services of Guanting Reservoir Basin are presented as asymmetric spatial characteristic; and (3) the eco-compensation mechanism is an important means to balance the asymmetry of ecosystem services between the upstream and downstream of Guanting Reservoir Basin and enhance the upstream capacity for provision of ecosystem services. The quantitative eco-compensation mechanism is the key point of follow-up research to enhance ecosystem services; the scenario analysis will have a prospective potential to propose some policy suggestions with more operability.
Lake and wetland ecosystem services measuring water storage and local climate regulation
