永定河官厅山峡河道内最小生态需水量的历时曲线法

Application of Flow Duration Curve Method in Calculating Instream Minimum Ecological Water Demand in Guanting Gorge of Yongding River

随着永定河下游河道内径流的逐年减少,永定河生态需水研究逐渐成为一个迫切的问题。现针对永定河官厅山峡段河道内生态需水,采用流量历时曲线法分析其流量历时情况,计算得到永定河官厅水库(坝下)站和雁翅站的河道内最小生态需水量为1.06亿m3和1.98亿m3,分别占年径流量的11.3%和26.3%。同时采用Tennant法对计算结果进行比较验证,两种方法得到的结果比较相近。在此基础上,根据研究河段的历史流量历时情况对最小生态需水量进行年内分配计算,将最小生态需水量从年尺度降到月尺度,得到年内各月的最小生态需水量,为永定河流域的水资源优化配置研究提供参考。

With the decreasing of water flow in the downstream of the Yongding River,the study of the ecological water demand has become an urgent problem.In this paper,the ecological water demand in the Guanting Gorge of the Yongding River is calculated using the flow duration curve method.The results show that the instream minimum ecological water demands at the Guanting reservoir（under dam） and Yanchi station of the Yongding river are 106 and 198 million m3,respectively,which account for 11.3% and 26.3% of the annual runoff,respectively.Meanwhile,the Tennant method is used to verify the results,which indicates that both methods yield similar outcomes.Following this,the annual distribution of the minimum ecological water demand for years is calculated according to the historical flow duration in the study area,by reducing the scale of the minimal ecological water demand from yearly to monthly,which can provide references for the optimal allocation of water resource research in the Yongding River basin.