Characteristics of rainfall-induced runoff pollution and its social influencing factors in main urban area of Chongqing City
To investigate the influence of social factors on the water quality of rainfall-induced runoff in the main urban area of Chongqing City,this study analyzed the inter-annual variations in the water quality of rainfall-induced runoff under policy influences from 2010 to 2021 and conducted a correlation analysis of pollutant indicators of rainfall-induced runoff.The logarithmic mean divisia index decomposition model was employed to quantify the effects of population size,technological innovation,economic development,and industrial structure on the water quality of rainfall-induced runoff.The findings revealed an improving trend in the water quality of rainfall-induced runoff in the main urban area of Chongqing City,accompanied by enhanced correlation between pollutant indicators.The water quality of roof runoff in 2019 and pavement runoff in 2021 improved to the range of"slightly clean to polluted".Suspended solids demonstrated significant correlations with COD,NH3-N,TN,and TP(p<0.01),with the correlation coefficient r>0.75 for roof runoff,and r>0.50 for pavement runoff.The air control policies have a significant effect on reducing roof runoff pollution,while effective implementation of sponge city and drainage system construction policies plays a crucial role in controlling pavement runoff pollution.Technological innovation and industrial structure are the dominant factors affecting the runoff water quality,while economic development and population size have negative effects on water quality improvement.
rainfall-induced runoff pollutionsocial influencing factorsNemerow comprehensive pollation indexLMDI decomposition modelmain urban area of Chongqing City