考虑水文变异的东江流域河道内生态流量研究

基于变化环境下河流水文情势发生变异的特殊性,应用滑动秩和检验法系统分析东江水文变异及其变异成因,确定变异前各月平均流量序列最适概率分布函数,将概率密度最大的月平均流量定义为河道内生态流量。分析表明,考虑水文变异的生态流量计算方法是合理可行的。水文变异后,东江流域干流满足生态需水的频率大大提高,满足频率从变异前的60%左右提高到变异后的73%以上(6月除外),非汛期提高幅度比汛期大。所得成果可为河道水文生态变化的研究提供参考。

Study on eco-flow in river channel of Dongjiang River Basin under consideration of hydrological variation

Based on the particularity of the variation from the hydrogical regime of the river under the changed environment，the hydrological variation of Dongjiang River and its causation are systematically analyzed with the moving rank-sum testing method，while the most adaptable probability distribution function of the mean monthly flow series of all the months before the variation is determined，and then the mean monthly flow with the maximum probability density is defined as the eco-flow in the river channel. The analysis shows that the method for the calculation of the eco-flow under the consideration of the hydrological variation is feasible and reasonable. After the hydrological variation，the frequency that the the eco-water demand is satisfied by the main stream of Dongjiang River Basin is largely enhanced，i.e. the satisfying frequency is enhanced from about 60% before the variation to above 73% after the variation （except June），moreover，the enhancing amplitude of the non-flood season is larger than that of the flood season. The result obtained herein can provide a reference for the study on the change of the river hydro-ecology.