河道生态基流量的年内同频率展布计算法

为更准确计算季节性强的河流的生态基流量,提出年内同频率展布法。该方法根据天然年径流资料,将一年划分为丰水期、枯水期、平水期,分别求取不同时期的同期均值比,并结合多月最小月均径流量,计算生态需水过程。将该方法应用于汾河干流,取其1965~2013年的天然径流资料,分别采用Tennant法、年内展布法和年内同频率展布法三种方法,计算汾河干流兰村、二坝、义棠三个测站的生态基流量。计算结果表明,年内同频率法相较其他方法更贴近天然状态下流量的年内丰枯变化,对河流生态治理有一定指导意义。

Equal Frequency Calculation Method of Ecological Base Flow

The paper puts forward a calculation method of ecological base flow towards northern rivers. According to natural annual runoff, one year is divided into three periods: wet season, normal level season and dry season, and each period''s percent of average flow in the same periods are calculated. Combined the least monthly average runoff within multiple months, the process of ecological water demand is calculated. Based on natural runoff data of Fenhe River during 1965-2013, Tennant method, dynamic calculation method and equal frequency method are used to calculate ecological base flow of three observation station: Lancun, Erba and Yitang. It indicates that the results by the proposed method is closer to dynamic change of ecological water demand and makes some sense to ecological management.