关键词: 濑溪河, 农业面源污染, 等标污染负荷, 综合评价, 分级评价

Abstract: [Objective] The objective of this study was to conduct comprehensive evaluation on the agricultural non-point source pollution on the scale of 10 towns along with the Laixi river in Lu county. And the corresponding recommendations and control measures were also proposed. [Method] List analysis was used to account the river pollution load of pollutants, including total phosphorus(TP), total nitrogen(TN), chemical oxygen demand(COD), ammoniac nitrogen(NH₃-N) produced from 7 kinds pollution sources. The equivalent pollution load method was adopted to analysis and evaluate various sorts of pollution sources and pollutant comprehensively, as well as the spatial contribution of each pollutant to Laixi river. The impact of spatial characteristics on the environment was also identified by the method of unit town area pollution load method, and then the grading evaluation system was established. [Results] The primary sources of pollution in the study area were poultry and livestock breeding, chemical fertilizer loss and rural domestic sewage. The main pollutants were TP and TN. The towns that have the largest pollution contribution were Fuji town, Xuantan town and Fangdong town;Fangdong town and Jiaming town has the most serious environmental pollution in the area, both of which have reached Ⅳ grade(serious threat). [Conclusion] It is already very serious that the problem of non-point source pollution of Lu county in Laixi river. Appropriate control measures should be taken according to the distribution and characteristics of non-point source pollution due to their significant spatial distribution differences.

Key words: Laixi river, non-point source pollution, equivalent pollution load, comprehensive evaluation, grading evaluation