Flood Control and Evaluation Study of Small Watershed Units and Urban Topography Landscape for Wuhan City

Abstract

Urbanization in China has continuously expanded with rapid economic development since the beginning of the twenty-first century. However, urban flooding events and disasters are increasingly frequent in major Chinese cities. This paper uses small watershed units as the research units and proposes a terrain control strategy for urban flooding mitigation and relief from a hydrological management perspective. This work further enriches the depth of research in this field and its certain practical implications include helping government departments to respond more efficiently to urban flooding; providing orderly protection, development, and construction of cities; and improving urban flooding governance and overall development. Wuhan City, a major city in central China, was selected as the research area. This study examines the correlation between and influence of urban topography and urban flooding. The lower the site elevation, the smaller the site relief, the lower the site roughness, and higher the likelihood that the site will experience urban flooding. Surface roughness is the topographical influencing factor with the greatest influence on urban flooding. This study combines urban flooding density and high risk SWUs in Wuhan to classify the flood risks at different city sites. Along with the backgrounds and conditions of the city, the results are used to propose a targeted and operable flooding-control evaluation system within Wuhan. The findings of this study have practical implications for future development and construction in Wuhan and provide a concrete solution for the mitigation of flooding problems.