基于径流还原的桑干河生态基流及其盈缺分析研究

考虑到流域内水循环及降雨径流关系,通过对径流还原后,采用生态基流计算方法,确定桑干河生态基流量,进行桑干河生态基流分析。针对桑干河罗庄-固定桥、固定桥-册田水库逐年计算时,采取逐项还原法,逐项还原断面以上未实测到的水量,加上断面实测径流,还原为断面天然径流量。采用Tennant法计算桑干河生态基流量,并与最小月平均流量法的计算结果进行对比。Tennant法生态基流量多年平均计算值介于25%和50%频率年的计算结果,符合实际情况。通过对桑干河灌区引水与河道实测径流变化对比,发现其引水对河道生态基流起到了制约作用,需要采取措施来解决生态基流的缺水问题。

Ecological basis flow and its sufficiency and lack of Sanggan River based on restoring computation of runoff

Considering the relationship between the water cycle and rainfall runoff in the basin, this paper is to study the Sanggan River ecological base flow and analyze its sufficiency and lack in Sanggan River by means of restoring computation of runoff and the basic ecological flow calculation. Concerning the annual runoff calculation of Luo Zhuang - Guding qiao and Guding qiao - Cetian reservoir in Sanggan River, the term by term restoring method was adopted. In order to obtain natural runoff of the section, the unmeasured water quantity was restored term by term and then added measured runoff to it. The Tennant method was used to calculate the ecological base flow of the Sanggan River and compared with the results of the minimum monthly average flow method. The average calculated value of the Tennant method over the years is between 25% and 50% frequency years, which accords with the actual situation of the river. Through comparison between the water diversion in irrigation area and the measured runoff variation of Sanggan River, it is found that the water diversion has restricted the ecological base of the river channel. It is necessary to improve the ecological base of the water shortage.