江苏南水北调供水区水质驱动因素分析

Analysis of driving factors for water quality in water supply area of South-to-North Water Transfer Project in Jiangsu Province

为确定影响江苏南水北调供水区水质的关键因素,开展江苏南水北调供水区的水质驱动力研究。立足江苏南水北调区域特点,针对水质污染治理成效,从经济社会发展水平、产业发展规模、水资源承载能力、典型污染物排放规模、水污染治理投资、生态环境政策6个方面选择驱动因素,建立24个自变量表征指标系。运用Step-Wise回归分析方法,得出水质驱动因素最优回归方程,结果表明:生活服务业用水量和COD区域排放量对水质影响最显著;在正向驱动因素中灌溉渠系水利用率及区域水污染治理投资对水质的影响最大。据此提出针对性水质改善对策建议,包括:分类量化污染排放当量及其长效管理责任,“倒逼”地方政府加大水污染治理投资;通过提高水价促进农业节水,减少农业污染物的携带性排放;优化水污染管制政策,严禁生活服务业污水直接排放;强化河道内源治理,控制淤积性污染扩散等。

In order to determine the key factors affecting the water quality of the water supply area of the South-to-North Water Transfer Project in Jiangsu Province,the water quality driving forces of the water supply area of the South-to-North Water Transfer Project in Jiangsu Province were studied.Based on the regional characteristics of the South-to-North Water Transfer Project in Jiangsu Province,and in view of the effectiveness of water pollution control,the level of economic and social development,the scale of industrial development,the carrying capacity of water resources,the scale of typical pollutants discharge,the investment in water pollution control and the policy of ecological environment were considered and 24 independent variable characterization indexes were established.Based on step-wise regression analysis method,the optimal regression equation of water quality driving factors showed that water consumption in domestic service industry and COD regional discharge had the most significant impact on water quality.Likewise,water use efficiency in irrigation canal system and investment in regional water pollution control among the positive driving factors had the greatest impact on water quality.Moreover,targeted water quality improvement measures were proposed to classify and quantify the pollutant discharge equivalent and its long-term management responsibility for forcing local governments to increase investment in water pollution control.In addition,to promote the agricultural water saving by raising water prices for reducing the agricultural pollutants discharge;to optimize water pollution control policies that strictly prohibited the direct discharge of sewage from domestic service industry;and to strengthen internal source governance for controlling siltation pollution diffusion were also suggested.