古蔺河流域古蔺县段农业非点源污染综合评价

Study on Estimating Method of Agricultural Non-point Source Pollution Based on Export Coefficient Theory

为了能准确估算古蔺河流域古蔺县境内农业非点源污染的输出负荷,确定出农田地表径流、畜禽养殖和农村居民生活污染中TN,TP输出量对水环境不同程度的影响。基于输出系数法,对研究区内三种污染源和两种污染物进行农业非点源污染综合评价,得到以下结果:研究区内农业非点源污染的输出总量为4 051.14t/a。其中TN负荷量为3 738.50t/a,TP为312.64t/a。从污染源角度分析,农田地表径流、畜禽养殖和农村居民生活三种污染源的总等标污染负荷比分别为16.57%,37.97%,45.45%。从污染物角度分析,TN,TP两种污染物的总等标污染负荷比分别为70.51%和29.49%。结果表明,农村居民生活和畜禽养殖污染是研究区内最主要的污染源,TN负荷量远大于TP为主要污染物,根据研究区的水污染情况,有针对性地提出农业非点源污染的防控措施。

In order to accurately calculate export loads of agricultural non-point source from Gulin River within the territory of Gulin County,TN and TP export loads for farmland surface runoff pollution,livestock pollution and pollution of agricultural population were determined.Based on export coefficient model,we comprehensively evaluated agricultural non-point source pollution of study area by using three kinds of pollution sources and two kinds of pollutants,and drew the following conclusions.The total pollution load from agricultural non-point pollution source was 4 051.14t/a.The loads of TN and TP were 3 738.50t/a and 312.64t/a.From the perspective of the pollution source,the total standard pollution load rates of farmland surface runoff,livestock and agricultural population were 16.57%,37.97%,45.45%,respectively.From the perspective of the pollutants,the total standard pollution load ratio of TN and TP were 70.51% and 29.49%,respectively.The results showed that rural resident living sewage and livestock pollution were the most main pollution sources.TN load was much greater than TP load so that TN load was the most main pollutant.With respect to the situation of water pollution,the agricultural non-point source pollution prevention and control measures were put forward.