浅析中小流域设计洪水的地区组成

Analysis of Regional Composition of Design Flood in Small and Medium River Basin

防洪设计中,设计断面上游调蓄作用较大的水库或分洪、滞洪等工程,对洪水具有调节作用,改变了天然洪水的状况,直接影响了下游设计断面的设计洪水。对中小流域而言,水文观测资料相对比较缺乏,为合理推求下游防洪控制断面设计洪水,从设计暴雨的地区分布着手,根据各分区洪水过程线,通过试算得出各分区洪水的组合方式,并分析得出下游控制断面的设计洪水成果。研究表明该方法切实可行,可以定性、定量分析上游水库调蓄作用对下游洪水的影响。

In flood protection design reservoirs or flood diversion and detention projects with significant flood-egulating functions at the upstream design section are of significance to flood regulation, because they change conditions of natural flood and have direct influences on the design flood to the downstream design section. For medium and small basins, the hydrological data are relatively limited. To accurately calculate the peak flow of downstream design section, in this paper we start from the regional distribution of design rainstorm, and then according to the flood hydrograph of each district, the combination mode of flood in each district is obtained by trial calculation, and the design flood results of downstream control section are obtained. The results show that the method is feasible and can provide qualitative and quantitative analysis of the influence of upstream reservoir regulation of downstream flood.