Study Of Rural Non-point Source Pollution In Shitoukoumen Reservoir Reach Based On GIS

Since the point source pollution has been controlled successfully, the influence of the non-point source (NPS) pollution to the environment has been revealed for its serious harm, hard to control, extensity and uncertainty, and one of the most serious among them is rural non-point source which become the main source of damaging the water quality. As the nitrogen and phosphorus from rural NPS pollution are significant important factors for water environment deterioration and landscape fragment of basin, the problems of controlling NPS in watershed have been focused in the world.Based on summarizing the literature domestic and abroad on NPS pollution study, the paper aim to quantify the pollutant and the pertinence analyzing between NPS pollution and the landscape's heterogeneity, focusing on Shitoukoumen reservoir up reach, which supplies drinking water for Changchun City and hardly be studied, the contend of study is as follows.1. Combining GIS technologies, locale investigation and the runoff experiment for measuring the concentration of pollutant, adopting USLE(Universal Soil Loss Equation) and SCS(the rain-runoff model from Soil Conservation Service USA), quantifying the soil erosion modulus, runoff, nitrogen and phosphorus from NPS.2. As for taking the landscape analysis method, firstly selecting two representative and different landscape region in Shuangyang reach whose river flows to Shitoukoumen reservoir. Then sampling the water in bayou and soil in different land-use type before and after rain, and then analyzing the correlation between rural NPS pollution and heterogeneity landscape (land-use especially in the paper). Last the paper probes the principle of optimizing the landscape pattern for controlling the NPS pollution.The annual rainfall of Shitoukoumen region is 650mm. More than 80% of the NPS pollution happened in rainy season, between July and September. The results show that.1. USLE and SCS models based on GIS were taken to calculate pollution load, and the soil erosion load was 2705115t, runoff was 1146.9184×10~4m~3, average erosion modulus was 508.It/km~2·a, the status of soil erosion was preferably.2. The data calculated by Mean Concentration Method in the watershed shows the output of Soluble N, Paniculate N, Soluble P, Paniculate P ware 340259.5 kg/a, 47178.96 kg/a, 23419.71 kg/a, 42864.56 kg/a respectively. So the main loss form of nitrogen is soluble, by contrast phosphorus is particulate.3. Through correlation analysis of pollutant in water-soil by local experiment and landscape pattern index in Dujia Village and Jiangjia Village basin in Shuangyang river watershed, the different land-use types were significant for the rural NPS pollution.