Urban land pattern impacts on floods in a new district of China

Abstract

Urban floods are linked to patterns of land use, specifically urban sprawl. Since the 1980s, government-led new districts are sweeping across China, which account for many of the floods events. Focuses of urbanization impact on floods are extending gradually from hydraulic channels, to imperviousness ratio, to imperviousness pattern in urban areas or urbanized basins. Thus, the paper aims to explore how urban land pattern can affect floods in urban areas to provide decision makers with guidance on land use and stormwater management. Imperviousness was generally correlated with spatial variations in land use, with lower imperviousness in less dense, new districts, and higher imperviousness in more dense, uniform/clustered development in local areas adjacent to hot nodes. The way imperviousness and channel are organized, and the location of imperviousness within a catchment, can influence floods. Local government's approach to new district planning, in terms of zoning provisions, has only considered some development aspects and has not adequately integrated flood management. A key issue for the planning should been done to adequately cater for flooding, particularly considering the benefits of keeping natural conveyance systems (rivers) and their floodplains to manage flood waters.