新沟河工程应急调水效果评估

Evaluation of emergency water diversion effect of Xingou River Project

为探究新沟河工程应急调水的相关问题,评估工程实际调度效果,基于新沟河工程应急调水试验期间实测水量水质数据,采用水质综合污染指数法,引入水质改善系数、类别变化指数等分析评估了新沟河工程沿线水质对引水的响应规律。结果表明:调水试验期间新沟河西支分流比为0.30~0.59,受到西支分流的影响,新沟河东支入太湖日均流量占新沟河日均引江流量的9%~22%,长江来水对京杭运河以南东支的影响时间约为西直湖港北枢纽开启并持续引水3 d后;干流水质改善效果与本底水质以及断面距离来水水源的远近有关,本底综合污染指数较大的断面,其最大水质改善系数总体较大,当断面本底水质状况接近时,距离来水水源较近的断面水质改善系数较大。

To explore the related issues in emergency water diversion of Xingou River Project,and to evaluate the water diversion effect,the pattern of influences on water diversion caused by variation of water quality in the basin under Xingou River Project was analysed based on the method of comprehensive pollution index,with the water quality improvement index(I)and the category change index(G)introduced.Results showed that during the water diversion period,the diversion ratio of the west main branch of Xingou River is 0.30~0.59.Affected by the diversion of the west main branch of Xingou River,the daily average water inflow of the east main branch of Xingou River into Lake Taihu accounts for 9%~22%of the daily average water quantity from the Yangtze River.Three days after the continuous water diversion through Xizhihugang-North Project,water from the Yangtze River has an impact on the east main branch of Xingou River,south of the Beijing-Hangzhou Grand Canal.The effect of water quality improvement in main stream is related to the background water quality of each section,as well as the distance between each section and the water source.For those sections with higher initial value of the comprehensive pollution index,the Imaxindex tends to be larger.For the sections with similar background water quality,the I index of those sections close to the water source tends to be larger.