2017年对于桥水库周边31条沟渠或季节性河流进行全面摸查，分别采用单因子评价法和综合污染指数法对水质现状进行评价。 单因子评价结果显示：库周沟渠Ⅲ类水体占比9. 5%，劣V类水体占比52. 11%，总体处于重度污染水平．主要污染因于是氮氧、总磷、化学需氧量。 综合污染指数评价结果显示水质最差的是燕各庄沟。综合污染 指数为48. 67，最好的是英庄子沟，综合污染指数为1. 45, 通过收集于桥水库周边气象、降水、水文、地形、土壤和土地利用类型等数据资料，采用SCS-CN法模拟沟渠地表径流量．乘以实测污染物浓度估算污染负荷，得出库周沟渠年输入化学需氧量723. 2t，总氮213. 9t，总磷ll. 4 t， 研究成果可为加大于桥水库水质保障和面源污染了台理力度、 斩断人库污染源、确保饮用水水源地安全提供科学依据。

The single factor evaluation method and the comprehensive pollution index (CPI) method were employed to evaluate the water quality of 31 ditches around the Yuqiao Resvervoir in 2017. The single factor evaluation results showed that the proportion of Ⅲ and the lower V were 9. 5% and 52.4%, respectively. The main pollution factors were ammonia nitrogen, total phosphorus, and chemical oxygen demand. The comprehensive pollution index results showed that the worst water quality was Yangezhuang ditch with CP1=48. 67 and the best was Yingzhuangzi ditch with CPI= 1. 45, respectively, Based on meteorology date，such as rainfall, hydrological data,topographic information, soil and land use records were collected to simulate the surface runoff of the ditches using SCS-CN method. Furthermore, the pollution load of the main pollutants was estimated after multipl ymghy the concentration of the pollutant. The results indicated that the annual input of chemical oxygen demand was 723. 2 tons,and total nitrogen was 213. 9 tons,while total phosphorus was 11. 4 tons, respectively. The research result would provide scientific evidence for strengthening the water quality safeguarding and non-point source pollution controlling of Yuqiao Reser voir, which moy benefit form reducing the reservoir inflow pollutants and ensuring the drinking water resource safety.

国家水体污染控制与治理科技重大专项（2013ZX07603-003-006)