Water Quality Dynamics in the Zhuxihe River Basin in Hainan Province, China: Insights from Temporal and Spatial Analysis

The Zhuxihe River has faced significant water quality challenges in recent years. Although control measures have been implemented, the pollution levels remain concerning. This paper aims to investigate the spatio-temporal variations in the water quality of the Zhuxihe River through field sampling, chemical testing, and synthetic evaluation. We collected 52 water samples in both dry and wet seasons along the main river and its tributaries. The evaluation, which utilized the integrated SFE-FCE method, identified MnO42−, NH3-N, TP, and TFe as the primary pollutants. In the dry season, MnO42− concentrations ranged from 1.6 mg/L to 19.8 mg/L, NH3-N ranged from 0.12 mg/L to 2.04 mg/L, and TP concentrations varied from 0.1 mg/L to 5.61 mg/L. In the wet season, MnO42− concentrations ranged from 4.9 mg/L to 13.9 mg/L, NH3-N from 0.27 mg/L to 1.73 mg/L, and TP from 0.07 mg/L to 1.31 mg/L. The results indicate the concentrations of MnO42− are higher in the wet season, and TP and NH3-N show seasonal fluctuations. Spatially, the downstream section of the main river faces the highest pollution levels. This study provides insights into the pollution dynamics of the Zhuxihe River, offering a scientific foundation for future research and water quality management strategies.