江苏省主汛期水体水质变化特征及污染防治对策研究

Research on the characteristics of water quality changes in the main flood season in Jiangsu Province and the countermeasures for pollution control

基于2017—2019年江苏省380个省级考核断面(以下简称省考断面)的水质数据,以COD、氨氮和TP为研究因子,探讨了江苏省内太湖流域、长江流域中除太湖流域地区(以下简称长江流域)和淮河流域主汛期前后水质变化趋势,以期为主汛期河湖水质保障提供科学支撑。结果表明:380个省考断面中,约60%的断面在主汛期水质指标浓度升高,其中氨氮和TP增幅较大;依据《地表水环境质量标准》(GB 3838—2002),2017—2019年主汛期省考断面中优于Ⅲ类标准的断面比例,相较于主汛期前分别降低了12.1、7.4、8.1百分点,劣于Ⅴ类标准的断面比例分别增加了1.4、0.3、4.6百分点;太湖流域主汛期水质有所波动,其中氨氮略有下降,COD、TP分别增加11.8%、8.5%;长江流域主汛期整体水质好转,COD、氨氮和TP分别下降1.4%、1.2%、16.6%;淮河流域主汛期水质恶化形势明显,氨氮、COD和TP增幅分别达74.9%、9.9%、17.8%;为保障汛期水环境质量,提升汛期水环境抗风险能力,建议从完善城镇污水管网、控制农业面源污染、监控上游来水和强化汛期水质保障等方面加强管控。

Based on the water quality data of 380 provincial inspection sections in Jiangsu Province,the water quality variation characteristics of Taihu lake Basin,Yangtze River Basin excluding Taihu lake Basin(hereinafter referred as Yangtze River Basin)and Huaihe River Basin before and after the main flood season were discussed with COD,ammonia nitrogen and TP as research factors.The result could provide scientific support for the water quality assurance of rivers and lakes in flood season.The results showed that in 380 provincial inspection sections,about 60%of the sections’water quality index increased in the main flood season,especially the increase of ammonia nitrogen and TP.According to the“Environmental quality standards for surface water”(GB 3838-2002),the proportion of superior ClassⅢsections in the main flood season decreased by 12.1,7.4 and 8.1 percent points respectively compared with that before the main flood season,and the proportion of inferior ClassⅤsections increased by 1.4,0.3,4.6 percent points respectively.The overall water quality of Taihu Lake Basin in main flood season fluctuated,with ammonia nitrogen decreasing a little and COD,TP increasing by 11.8%and 8.5%;the water quality of the Yangtze River Basin improved,with COD,ammonia nitrogen and TP decreasing by 1.4%,1.2%,16.6%respectively;the water quality of Huaihe River Basin deteriorated sharply,with the increase rates of ammonia nitrogen,COD and TP reaching 74.9%,9.9%and 17.8%respectively.In order to ensure the water environment quality and improve the anti-risk ability of water environment in flood season,some suggestions were proposed such as improving the urban sewage pipe network,controlling agricultural non-point source pollution,monitoring upstream water and strengthening water quality guarantee in flood season.