Specificality, Quality Variation, Assessment and Treatment of Estuarine Water in the Pearl River Delta, South China

The Pearl River Delta (PRD) is a major economic and manufacturing area in South China. Using the comprehensive and authoritative monitoring data, this study conducted a systematic review of the regularity of marine disasters (e.g., storm surges, saltwater intrusions, and red tides), water quality variations, water quality risk assessments and wastewater treatment in seven sections of the Pearl River Estuary (PRE). The total water resources in the PRD have been a decreasing in recent years. Seasonal marine disasters occur frequently, causing loss of life and economic damage. A monitoring and early-warning system was constructed to provide a scientific basis for dealing marine disasters response. Based on the water quality monitoring data from the seven main PRE sections from 2015 to 2020, chemical properties, heavy metal concentrations and comprehensive pollution indices were selected as indicators. The water quality of the seven PRE sections, flowing westward into the South China Sea improved over time. According to a water quality risk assessment, Yamen the estuary nearest the sea is at the highest risk. The PRD had a wastewater treatment rate of 97.37%, which was equal to the average of Guangdong Province. These findings can be used to predict future trends in estuarine water, quality and inform future studies of water quality variations in the PRD.