长江中下游小流域水质综合评价研究

Study on comprehensive evaluation of water quality in the middle and lower reaches of Yangtze River

选取秦淮新河和板桥河作为长江中下游南京段典型支流,以2023年1—12月沿河11个泵站的在线监测数据为基础,采用单因子评价法、综合污染指数法、主成分分析法和Spearman秩相关系数法对水环境质量及主要污染因子进行综合评价。结果表明:秦淮新河整体水质情况优于板桥河,主要超标因子为氨氮和总磷。秦淮新河地表水Ⅳ类达标率较高,综合污染指数趋于减小,各水质指标间相关性良好。板桥河流域除王家山泵站、B地块泵站和古雄泵站外,其余泵站水质大部分满足地表水Ⅳ类标准,综合污染指数高,主成分分析法得分均大于6,主要受溶解氧、氨氮和高锰酸钾指数影响,各指标间相关性弱。基于评价结果,可对相关水质进行预警预测和提出针对性治理措施,继而提升长江流域生态环境质量。

The Qinhuai New River and Banqiao River were selected as typical tributaries of the Nanjing section of the middle and lower reaches of the Yangtze River.Based on the online monitoring data of 11 pumping stations along the river from January to December 2023,the water environment quality and main pollution factors were evaluated by single factor evaluation method,comprehensive pollution index method,principal component analysis method and Spearman rank correlation coefficient method.The results showed that the overall water quality of Qinhuai New River was better than Banqiao River,and the main pollutants exceeding the standard were ammonia nitrogen and total nitrogen.The ClassⅣstandard of surface water of Qinhuai New River was high.The comprehensive pollution index tended to decrease.There was good correlation among the water quality indexes.Except Wangjiashan pumping station,Block B pumping station and Guxiong Pumping station,the water quality of the other pumping stations mostly met the ClassⅣstandard of surface water,with high comprehensive pollution index of Banqiao River Basin.The scores of principal component analysis were all greater than 6,which were mainly affected by dissolved oxygen,ammonia nitrogen and potassium permanganate index,and the correlation among each index was unsignificant.Based on the evaluation results,targeted measures can be taken for relevant water quality,thereby improving the ecological environment quality of the Yangtze River Basin.