考虑降雨时空变化的单位线研究

A Unit Hydrograph Model Considering Spatio-Temporal Variation of Rainfall

流域降雨的时空变异性和地形地貌特征,以及不确定性因素对单位线的影响始终是流域汇流计算方法研究的难点问题。本文分析了传统的根据降雨时空分布不均匀性对单位线进行分类的方法及其缺点,推导了考虑暴雨重心位置和降雨强度的影响的S曲线法,给出了新的S曲线方程,建立了S曲线参数与暴雨重心位置和降雨强度的关系,采用该方法可求得任一暴雨重心位置及任一降雨强度下的时段单位线。该方法具有谢尔曼经验单位线简便实用的特点,又具有考虑降雨时空变异性的优点,在沮河流域洪水预报模型中的应用表明该方法是可行的。

For many years, the impaction of watershed morphologic and topographic structure and ral variation of rainfall on unit hydrograph has been the key question in studying method of routing. This paper introduced the traditional classifications of unit hydrograph according to the spatio-tempowatershed flow spatio-temporal variation and analyzed their disadvantages. A new S-curve method considering the spatio-temporal variation of rainfall was proposed. The relationship between the parameters of the new S-curve equation and the barycenter of storm and the intensity of rainfall was found. The unit hydrograph with changing position of storm barycenter and intensity of rainfall can be built by using this method, which has the characteristics of Sherman unit hydrograph and also consider the temporal-spatial variation.