Water quality improvement and existing challenges in the Pearl River Basin, China

This study highlights the effectiveness of a national water quality improvement initiative on water quality in the Pearl River Basin. The dynamic characteristics of surface water quality in the Pearl River Basin from 2006 to 2018 were analyzed, and the effects of driving factors, including economy, population, land use, water resources, forestry, industry, energy and animal husbandry on water quality were determined. There was a significant improvement in the overall water quality of the Pearl River basin (except Guangzhou) by controlling the discharge of wastewater pollutants and emphasizing environmental protection of forests and disposal of domestic waste. That is particularly evident from the exponential decrease of GDP normalized ammonium (NH4+-N) and COD concentrations. The modeling of water quality and driving factors indicates water quality in the Pearl River Basin was closely related to industrial pollution control investment, afforested area, innocuous disposal capacity of domestic garbage, vegetable sown area, use of natural gas, ecological water consumption, production of sulfuric acid and mutton yields. The improvement in water quality occurred at a time when GDP was increasing providing evidence that economic development and environmental protection can occur through appropriate environmental investment. It is worth noting that although water quality in Guangzhou has improved, nitrogen pollution resulting from domestic sewage and industrial pollutants remains a severe challenge for water quality in this region.