确定河道内适宜生态流量的几种水文学方法——以沙颍河周口段为例

适宜生态流量是保障河流水生态系统健康的重要变量,合理评估适宜生态流量具有现实意义。以淮河流域典型河流沙颍河为研究对象,基于沙颍河周口水文站44年天然日流量数据,运用常用的5种水文学方法计算沙颍河的适宜生态流量,通过比较5种水文学方法在计算适宜生态流量方面的优劣发现:在水量需求方面,Q50_Q90法水量需求最大,Tennant法水量需求最小,Q50_Q90法会加重"三生"用水矛盾;在水文节律模拟方面,Tessman法、月流量变动法和Lyon法较Q50_Q90法和Tennant法有明显优势;在月流量满足率方面,Tennant法和Lyon法满足率最高,其中枯水期Lyon法满足率最高。综合考虑水量需求、水文节律和满足率三方面因素,Lyon法在计算沙颍河这类季节性河流的适宜生态流量结果最为合理。

Comparison of several hydrological methods to determine the ecological flow for instream river——A case study of Zhoukou hydrological station in Shaying River

As the amount of ecological flow is one of the important factors in maintain aquatic ecosystem,the accurate estimation of it has important practical significances.The Shaying River,a typical river in the Huai River Basin,was used in this study.In order to explore the advantages and disadvantages of five commonly used hydrological methods,the ecological flow was estimated based on the 44year natural daily streamflow data at Zhoukou hydrological station.The results showed that the Q50_Q90 method had the largest water demand and the Tennant method had the smallest.Q50_Q90 method would increase water pressure.Meanwhile,the simulation result of natural flow regime with different hydrological methods showed that the Tessman method,the Monthly Flow variation method and the Lyon method all had obvious advantages over the Q50_Q90 method and the Tennant method.It was found that the Tennant method and the Lyon method had the highest satisfaction rates than the other method,and the Lyon method had the highest satisfaction rates in dry hydrological years than other four methods.Therefore,the Lyon method was the most reasonable method to calculate the ecological flow in seasonal river,such as Shaying River.