“引江济太”新建工程对梅梁湾总磷总氮分布的影响

2016年以来,太湖水体总磷(TP)浓度上升且在2017年暴发大面积蓝藻,严重威胁了太湖水环境安全。2020年“引江济太”新建工程———新孟河延伸拓浚工程和新沟河延伸拓浚工程正式启用,将在已投入使用的望虞河引水工程基础上进一步提高进出太湖水量,为改善太湖水环境提供新的解决方案。文中通过建立太湖二维水动力-水质模型,模拟并分析“引江济太”新建工程中,太湖梅梁湾在不同季节盛行风下TP和总氮(TN)的迁移扩散规律。模拟结果表明,在夏半季与冬半季盛行风向作用下,不同引排量水对梅梁湾水域TP和TN的浓度影响与分布趋势存在差异性,当引排水量增加时,区域水体水质提升。

Influence of the Newly-Built Project of "Yangtze River-Taihu Lake Water Diversion" on TP and TN Distribution in Meiliang Bay

Since 2016,the concentration of total phosphorus(TP)in Taihu Lake had increased and cyanophyta pollution incident broke out in 2017,which had seriously threatened the water environment of Taihu Lake.In 2020,the newly-built project of"Yangtze River-Taihu Lake water diversion",including Xinmeng River extension and dredged project and Xingou River extension and dredged project would be put into operation.On the basis of Wangyu River diversion project that has been put into use,the amount of water entering and discharging Taihu Lake will be further increased,which will be new solutions to improve water environment.This paper established a two-dimensional hydrodynamic-water quality model of Taihu Lake to simulate and analyze the migration and diffusion laws of TP and total nitrogen(TN)in the Meiliang Bay of Taihu Lake under prevailing winds in different seasons in the newly-built project of"Water Diversion Project from the Yangtze River to Taihu Lake".Simulation results showed that under the effect of prevailing wind direction in summer and winter,different water entering and discharging had different effects and trends on TP and TN concentrations in the waters of Meiliang Bay.When the amount of diversion and drainage increases,the water quality of regional water body would be improved.