Comprehensive Evaluation of Water Quality and Non-point Source Pollution in Anju Section of Qiongjiang River Basin

LIU Lingxue;AO Tianqi;HU Zheng;HU Fuchang;LI Mengrui;College of Water Resources & Hydropower, Sichuan University;State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University;

Qiongjiang River Basin;;non-point source pollution;;water quality evaluation;;export coefficient method;;source strength coefficient method

In order to clarify the water quality of Anju Section of the Qiongjiang River Basin, the main pollution sources, major pollutants and key townships in the basin were accurately assessed to provide the theoretical basis for local water pollution control and treatment. The improved Nemero index method was used to evaluate the water quality of the study area, the export coefficient method and source strength coefficient method were combined to analyze the non-point source pollution from 21 townships, 5 pollution sources and 3 pollutants in Anju District. The results showed that the water quality of the whole study area was poor, and the water quality during the flooding season was inferior to that in the dry season; the non-point source pollution of the basin was serious, and the main pollution sources were sewage of urban residential areas, farmland surface runoff and livestock and poultry farms; the main pollutant was ammonia nitrogen(NH_3-N), total phosphorus(TP) came to the next; Anju Town, Lanjiang Town and Ximei Town contributed greatly to the pollution of the study area. In general, the non-point source pollution in the study area was greatly different in spatial distribution. It is suggested that the corresponding measures should be taken according to non-point source pollution distribution and its characteristics in the process of control and governance.