长江流域生态流量满足程度及其保障措施研究

Study on satisfaction degree of ecological flow and its guarantee measures in Changjiang River Basin

保障和管理河湖生态流量是加强水资源开发利用管控的基本要求,是实施“长江大保护”和“高质量发展”的重要内容。采用Qp法、Tennant法等生态流量计算方法,结合流域综合规划、水量分配方案、环评批复及取水许可等已有成果,计算确定长江流域重要河流控制断面的生态流量;采用1956~2016年控制断面长序列月均及日均径流数据,分析各控制断面生态流量满足程度。结果表明:长江流域重要河流主要控制断面除彭山、日喀则、海埂、宜昌断面月均生态流量满足程度较低,分别为87.6%、92.1%、92.1%和74.9%以外,其余控制断面生态流量月均满足程度均高于95.0%;各控制断面的日均生态流量满足程度均高于90.0%,采用2012~2016年近5 a的日均数据分析可知,清江高坝洲和抚河李家渡2个控制断面生态流量日均满足程度低于90.0%,分别为88.0%和85.0%,主要原因是天然来水偏枯及上游水利工程调度管理监管不严。根据分析结果,从健全法规体系、强化工程生态调度、完善监测体系、加强监督检查及科学研究等方面提出了长江流域片生态流量保障措施,可为流域水资源保护监督管理提供参考依据。

Guaranteeing and managing the ecological flow of rivers and lakes are the basic requirement of strengthening the control of water resources development and utilization,and are important contents of implementing“The majorprotection of the Changjiang River”and“The high-quality development”.Combined with the research findings of the comprehensive regulation,the water quantity allocation scheme,the environmental impact assessment documents and the water license of the Changjiang River basin,Q p method and Tennant method were applied to determine the ecological flows of important monitoring sections in the Changjiang River Basin.Long term monthly and daily mean runoff data from 1956 to 2016 were used to analyze the satisfaction degree of ecological flow in each monitoring section.The results indicated that the monthly average satisfaction degrees of the monitoring sections were higher than 95%,except for Pengshan,Rikaze,Haigeng and Yichang,the monthly average satisfaction degrees of which were 87.6%,92.1%,92.1% and 74.9%,respectively.According to the analysis of average daily data from 2012 to 2016,the average daily satisfaction degree of ecological flow of each monitoring section was higher than 90%,except for Gaobazhou(88.0%)in Qingjiang River and Lijiadu(85.0%)in Fuhe River.This might be due to the less-than-normal rainfall and the poor supervision on the dispatch of the upstream water conservancy projects.Finally,in order to provide references for the supervision and management of water resources in the Changjiang River Basin,we suggested measures to guarantee the ecological flow of the Changjiang River Basin from the perspectives of improving the legal system,strengthening ecological engineering scheduling,improving the monitoring system,reinforcing supervision,inspection and scientific research.