Influence of land use type and rainfall on the water quality of North Canal basin in Beijing, China

Abstract

Abstract Influence of land use type and rainfall on the water quality of North Canal basin in Beijing was evaluated.The monthly monitoring data of 63 water quality stations from 2015 to 2021, the land use type data from 1980 to 2020, the rainfall and runoff data of the North Canal basin in Beijing from 1919 to 2021 were analyzed. Results showed that the water quality of the North Canal basin in Beijing was getting better year by year, and showed temporal and spatial variations. In general, water quality in flood season was better than that in non-flood season, and better in upstream than that in downstream.Cluster analysis showed that the 63 water quality stations were divided into three types. Spearman correlation analysis results clarified that the concentration of water quality indexes were significant negatively correlated with forest land, and a positive relationship between cultivated land and water quality indexes in flood season or non-flood season.In addition, the concentration of CODMn, NH3 and TP were significantly positively correlated with rainfall in flood season, and the concentration of TN was negatively related to rainfall in non-flood season.This study provided important support for scientific and reasonable promotion of urban water environment management at the basin scale.