缺资料流域农业面源污染负荷研究与综合评价

Load study and comprehensive evaluation of agricultural non- point source pollution in ungauged catchments

在充分考虑降雨和地形对面源污染物传输影响的条件下,为能有效解决缺资料流域农业面源污染定量化估算和综合评价的问题,以古蔺县境内的古蔺河流域为例,基于改进的输出系数法和源强系数法,将研究区内3类污染源和4种污染物的输出负荷进行定量估算;采用等标污染负荷法对该流域农业面源污染进行综合评价。结果表明:研究区中农业面源污染严重,其中主要污染源为农村居民生活污水和畜禽养殖,占总等标污染负荷的74.19%;主要污染物为TN、TP和NH3-N,占总等标污染负荷的95.83%;对古蔺河污染贡献度较大的乡镇依次为古蔺镇、双沙镇和石宝镇,占总等标污染负荷的23.32%。根据分析结果,古蔺河流域应加强农村居民生活污水、畜禽养殖粪便及废水等有机废物的治理,合理施肥,减少氮磷流失。

By fully considering the effect of precipitation and terrain on pollutant transport,in order to solve the problems of the quantitative estimation and comprehensive evaluation of agricultural non- point source pollution in regions with sparse data,taking Gulin river basin within the territory of Gulin county as an example,the quantitative estimation for three kinds of pollution sources and four kinds of pollutants in the study area was given by combining improved export coefficient method and source strength coefficient method. The equal standard pollution load method was adopted to evaluate agricultural non- point source pollution in the region. The results showed： the study area of agricultural non- point source pollution was serious; the main pollution sources are rural residents living sewage and livestock breeding,accounting for 74. 19% of the total equal standard pollution load; the main pollutants are TN,TP and NH3- N,accounting for 95. 83% of the total equal standard pollution load. The towns that had larger pollution contribution were Gulin,Shuangsha and Shibao,accounting for 23. 32% of the total equal standard pollution load. According to the results of comprehensive evaluation,it is still necessary to strengthen the organic waste management in the basin,such as rural residents living sewage and livestock breeding waste,reasonably use fertilizers,and reduce the loss of nitrogen and phosphorus.