The Changes of County River Water Quality and the Characteristics of Pollution Discharge under the River Chief System: A Case Study of Peng'an County,Nanchong City

In order to explore the mechanism advantages of the river chief system in the county water environment management, this paper took Peng'an County in Nanchong City as an example to compare the environmental monitoring results before and after the river chief system, and studied the water quality changes and pollutant discharge characteristics of the county river. Before and after the implementation of the river chief system from 2016 to 2021, the proportion of river water quality in municipal counties increased from 0% to 100%, basically eliminating Class V of the tested sections, including chemical oxygen demand, permanganate index, ammonia nitrogen, total P and dissolved oxygen concentration, showing a good upward trend. On the basis of county river pollutant discharge and source analysis, water pollutant emissions changed not significantly from 2017 to 2019,however, pollutant emissions decreased rapidly from 2020 to 2021 with significant energy conservation and emission reduction effect and the advantages of the river chief system mechanism. At the same time, the paper has studied the water quality target assessment measures in the implementation of the river chief system, which could provide an important support basis for the consolidation of the achievements of water pollution prevention and control in Nanchong city.