基于变区间阈值法的河道生态需水计算方法

Calculation Method of River Ecological Water Demand Based on Variable Interval Threshold Method

针对河流天然来水丰枯情况不同的特征,提出了一种考虑年内径流变化程度的生态需水计算方法—变区间阈值法,在枯水期生态需水仅设定下阈值,丰水期则须同时设定上、下阈值。通过与Tennant法和分布流量法对比分析,结果表明:变区间阈值法性能不弱于分布流量法,且非劣解集的分布较Tennant法更均匀;在2月份水位有所下降,有利于抵御咸潮入侵;在3-5月份出库流量较大,有利于生态环境和鱼类产卵期产卵;降低了枯水期对径流资料的依赖,便于计算。丰富了现有生态需水计算方法,可为相关研究提供技术支持和参考依据。

In view of the different characteristics of the natural river runoff,a calculation method of ecological water demand,which takes in‐to account the variation of annual runoff,is put forward,the upper and lower thresholds shall be set at the same time in flood seasons.Com‐pared with Tennant method and distributed flow method,the results show that the performance of variable interval threshold method is not in‐ferior to that of distributed flow method,and the distribution of noninferior solution set is more uniform than that of Tennant method,it is ben‐eficial to resist the invasion of the saltwater tide,the discharge of the reservoir is larger in March and May,which is beneficial to the ecologi‐cal environment and the spawning period of the fishes,and the dependence of the runoff data in the dry season is reduced,which is easy to calculate.It enriches the existing calculation methods of ecological water requirement and provides technical support and reference for relat‐ed research.