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以ArcGIS9.2为平台,构建了生态系统减轻集水区出口受纳水体非点源污染服务物质量和价值量评估模型。包括模拟集水区范围,根据各种土地利用/覆被类型的污染物质输出及过滤污染能力系数,沿汇流路径,模拟集水区内每个栅格像元被植被移除而未进入水环境的污染物质量空间分布特征。价值量模型结合期望水质标准和净化污染物的边际成本进行计算。以磷素作为指示污染物,在二滩水库的集水区进行了模型的运用。结果表明:二滩水库集水区南部的河道附近是水文敏感区。其中盐源县腹地的农作区、西昌市与冕宁县,以及集水区最北端的称多县、中部的甘孜县等部分地区是是磷素关键污染源区。2000年被集水区生态系统过滤移除而未进入水环境的磷素污染物质总量达到978.90t.a-1,占关键污染源区指数总量的81.88%。林地生态系统服务价值贡献率最高。2000年集水区生态系统对于减轻其出口受纳水体磷素非点源污染服务的总价值为1370.18万元。
Using ArcGIS 9.2 as a platform, an ecosystem assessment model was established to reduce the quantity and value of services for non-point source pollution of the receiving water at the outlet of a catchment. Including the simulated catchment area, each grid cell in the simulated catchment area was removed by vegetation along the confluence path without entering the aquatic environment, based on various land-use / cover-type pollutant output and filtration pollution capacity coefficients The spatial distribution of pollutants quality. The value volume model is calculated by combining the expected water quality criteria with the marginal cost of cleaning up the pollutants. Using phosphorus as an indicator pollutant, the model was applied in catchment area of Ertan reservoir. The results show that the waters near the watercourse in the south of Ertan Reservoir catchment are hydrologically sensitive areas. Among them, the farming area in the hinterland of Yanyuan County, Xichang City and Mianning County, and the most northern part of the catchment area, and the parts of Ganzi County in the central part are key sources of phosphorus pollution. In 2000, the total amount of phosphorus pollutants that were removed by the catchment ecosystem without entering the water environment reached 978.90t.a-1, accounting for 81.88% of the total index of key pollution source areas. The value of forest ecosystem service contribution is the highest. In 2000, the total value of water catchments ecosystem for mitigating the non-point source phosphorus pollution of the receiving water bodies receiving export was 13,701,800 yuan.