基于改进的Tennant法的博尔塔拉河生态需水量计算

Calculation of Ecological Water Demand of the Bortala River Based on the Improved Tennant Method

河道生态需水是当前水资源研究的热点,其中计算方法是研究的重点。目前,计算河道生态需水的方法总体分为历史流量法、水力定额法、栖息地法、整体分析法等。通过对各种方法优缺点的对比分析,认为Tennant法较适合基础资料薄弱的干旱区河道生态需水量的计算。而该法用多年平均流量百分比来计算生态需水,不能反映生态需水的年际变化和年内季节性变化。因此,采用典型年流量代替多年平均流量,对Tennant法进行了改进,并对博尔塔拉河温泉站到博乐站的生态需水进行计算。结果表明:温泉站到博乐站河段一般用水期、用水高峰期河道最小生态需水量分别为0.22×10~8m^3、1.34×10~8m^3,较改进前增加4.5%、48.5%,计算结果更好地反映了博尔塔拉河径流季节性变化大的特点。

Ecological water demand of river is currently one of the hot fields in researching water resources,and its calculation method is the focus. So far,the calculation method of ecological water demand of river is generally divided into four categories,i. e. the historical discharge method,hydraulic rating method,habitat method and holistic method. Through comparative analysis of the advantages and disadvantages of various research methods,it was considered that the Tennant method is more suitable for the rivers in arid area where the hydrological data are insufficient. However,the ecological water demand calculated with this method based on the percentage of average annual discharge cannot reflect the annual and seasonal discharge variation. Therefore,in this study the typical annual discharge was used to replace the average annual discharge,thus the Tennant method was improved,and the ecological water demand of the river section from Wenquan Station to Bole Station of the Bortala River was calculated. The result showed that the minimum ecological water demands of the river section in common season and peak season were0. 22 × 108m3 and 1. 34 × 108m3,and they were increased by 4. 5% and 48. 5% compared with those before improving the method,respectively. The calculated results could reflect the big seasonal runoff change of the Bortala River.