【摘要】 本文利用SWAT(Soil and Water Assessment Tools)模型,在GIS技术和流域数字高程模型的支持下,对北京密云水库北部区域进行了流域非点源污染模拟研究,建立了一套适用于SWAT模型的研究区非点源污染基础信息库;根据2000—2002年的气象、水文、水质等监测数据,对研究区非点源污染负荷的时空变化进行模拟。结果表明,在空间尺度上,白河流域产流(占总流域的47.75%)、产沙(占总流域的53.65%)最大,但潮河水系含沙量(占总流域的62.55%)最大;单位面积氮磷流失量最高区域在潮河水系的东部丘陵区安达木河控制流域,其次为西部山地区的白河水系控制流域,流失量最低的区域出现在潮河水系中部冲积扇区主河道控制流域。在时间尺度上,8月份流量最大,占雨季总流量的51.48%;而硝态氮和矿物质磷在9月份输出最大,分别占雨季总输出83.64%和50.55%。不同土地利用类型非点源污染流失负荷不同,不同土地利用类型非点源污染流失负荷不同,耕地负荷贡献最大,其次是农村居民点,林地的污染负荷贡献最小。更多还原

【Abstract】 SWAT(Soil and Water Assessment Tool) model is a watershed scale model developed to predict the impact of land use practices on waterflow,sediment,and agricultural chemical yields in large watersheds over long periods.SWAT model was applied to simulate the nonpoint source pollution(NPS) loading in the north watershed of the Miyun Reservoir-the most important source of drinking water supply in Beijing.The basic database for SWAT model in the study area has been established using the GIS and Visual Foxpro6.0 technology.The simulation of NPS loading was carried by SWAT model using three years(2000-2002) data.The spatial and temporal variations of loadings were then analyzed.At the spatial scales,the watershed of the Baihe River had higher flow and sediment loads;however,the Chaohe River had high water content of sediment.The eastern hilly watershed of the Andamu River exhibited the highest nutrient load per unit area,followed by the western mountain area of the Baihe River watershed,and the lowest load was from the central alluvial plain of the Chaohe River watershed.On the temporal scale,the highest flows were observed in August and highest nutrient load in September.Woodlands contribute the smallest NPS loading,orchards are the second smallest contributor,and farmlands contribute the highest NPS loading.Wastewater discharge from villages is the second highest contributor.更多还原