基于 Global Mapper 的中小流域暴雨洪水分析

近年来， 随着城市化的发展，基础设施的建设规模日益扩大。道路设计过程中的桥梁和涵洞布设需要满足防洪要求，构筑物设计前必须经过桥涵水文计算， 其是确定桥梁跨径、 涵洞孔径的基本参数之一。桥涵水文计算前的重要基础工作是进行现场洪水调查， 获得流域的汇水面积。汇水面积一般在实测地形图上根据分水岭勾勒， 但项目推进过程中尤其是前期方案阶段，很难获得大比例的地形图。网上的卫星地图是可以参考的资源之一，利用Global Mapper软件， 结合某市政道路工程，进行流域汇水面积计算， 利用《四川省中小流域暴雨洪水计算手册》中的暴雨推理法，计算暴雨流量， 并以某桥跨布设进行过流断面复核。

Analysis of Rainstorm and Flood in Small and Medium Basins Based on Global Mapper

In recent years, with the development of urbanization, the scale of infrastructure construction is expanding day by day. The layout of bridges and culverts in the road design process needs to meet the flood control requirements. The hydrological computation of bridge and culvert must be done before a structure is designed, which is one of basic parameters to determine the bridge span and culvert aperture. The important basic work before the hydrological computation of bridge and culvert is the on-site flood investigation to obtain the catchment area of the basin. The catchment area is generally outlined on the measured topographic map according to the watershed, but it is difficult to obtain a large proportion of topographic maps during the project process, especially in the early scheme phase. The satellite map on the Internet is one of the resources for reference. By utilizing Global Mapper software, combined with a municipal road project, the catchment area of the basin is calculated. By using the rainstorm organon in Handbook for Calculation of Rainstorm and Flood in Small and Medium Basins of Sichuan Province, the rainstorm flow is calculated, and the cross-flow section of a bridge span is rechecked.