Research on water quality improvement effects of China’s Battle against Black-Odor water bodies

Given the sustained momentum of China's urbanization, the proliferation of black and odorous water bodies has emerged as a foremost predicament within urban settings. Since 2015, China has enacted a succession of policies aimed at mitigating the predicament of black and odorous water bodies. Nevertheless, there is a paucity of research assessing the impact of black-odor governance on water quality at the monitoring-section level. This study constructs the Black and Odorous Comprehensive Index (BOCI) to appraise the efficacy of remediating black and odorous water bodies at the monitoring-section level in China. Utilizing monthly water quality data from national monitoring sections spanning 2016 to 2018, the BOCI index is applied to evaluate the improvement in water quality within black and odorous water bodies, the enhancement of water quality in associated sections, and to quantitatively analyze the remediation effects resulting from the battle against black and odorous water bodies. The results indicate that a significant enhancement in the water quality of black and odorous water bodies in China. Notably, this improvement is most pronounced in water bodies facing more adverse environmental conditions. The Battle Against Black-Odor Water Bodies initiative has effectively compelled local governments to address issues associated with black and odorous water bodies by means of inspections, investigations, and other measures, leading to favorable outcomes.