基于L-THIA模型的密云水库地区非点源污染空间分布特征

农业生产营养物质的输出是造成水环境污染的重要原因之一。该文以北京密云水库周边地区为研究区域，基于土地利用、土壤以及降水等下垫面信息，利用长期水文影响评价(The Long-Term Hydrologic Impact Assessment，L-THIA)模型，估算研究区内污染物的长期平均输出负荷，并分析其空间分布特征。研究结果表明：不同土地利用类型的污染物输出负荷是不同的，其中以农用地对研究区内非点源污染的影响最大。结果表明，在流域规划和管理中使用L-THIA模型分析农业非点源污染的空间分布是可行的。

Spatial distribution characteristics of non-point pollution of Miyun reservoir areas based on L-THIA model

The output of agricultural nutritive substance is the one of main cause for water environment pollution. Taking Miyun reservoir in Beijing as study area, combined with the land use, soil and precipitation data, under the support of the GIS and RS technology, the long-term average pollution loads in study area were estimated using the Long-Term Hydrologic Impact Assessment(L-THIA) model. The spatial distribution of the pollution loads was analyzed. Results indicate that the pollution loads are different under different land use types, and the agricultural land has the most important impact on non-point pollution in the study area. The result of this research shows that L-THIA model is available for the spatial distribution of non-point pollution and it can provide the service for planning and management of the watershed.