Integrated risk management of flood disasters in metropolitan areas of China

A review of flood disasters in China during the past five decades has shown a steady increase in the disaster toll due to rapid urbanization, especially through landscape urbanization in metropolitan areas. This paper illustrates the relationship and the interactions between urbanization in the metropolis and the process of flood disaster changes. Furthermore, a solution is proposed to alleviate fluctuations in flood disasters through the adjustment of the land use structure and pattern in metropolitan areas. Based on the solution, the authors conclude that the proportion of 'ecological land' in metropolitan areas should not be lower than 40%. The proportion of water and wetlands in ecological land should not be lower than their area in the years of average precipitation and water level. This means that in the Pearl River Metropolitan Area and the Yangtze River Delta Metropolitan Area, the proportion of water and wetlands in ecological land should be more than 25%. Moreover, the authors propose constituting a regional management mode which combines government, society, and insurance companies for controlling flood risk in metropolitan areas.