Flood risk management in planning and construction of city: the Guangzhou experience

Abstract

Recently, urban flood disasters caused by rainstorm has happened more and more frequently. Chinese government has proposed that the urban flood disasters problem should be solved by integrated and systematic approach. The analysis of the historical rainstorm flood events of Guangzhou in the past 10 years showed that, the urban rainstorm flood has happened more frequently in lowland, hardening underlying surface and drainage system jacked by high water level. Guangzhou has innovatively delimited high-risk regions by watershed units, using Remote Sensing (RS) data and GIS data, which become the basis of flood risk management. The vertical planning, the storage capacity and river managing boundary have become three important conditions, which should be taken into consideration in the construction projects and serve as the basis for the whole life cycle. As a pioneer, Guangzhou has provided experience for metropolis to reduce flood risk in the construction stage. This paper analyzes the changes and causes of the overall flood safety situation in Guangzhou, and introduces the practice and exploration in Guangzhou from the aspects of promoting the accurate identification of flood risk areas, guiding the spatial control of flood control and drainage safety with planning, establishing the planning transmission mechanism, implementing the flood risk assessment system, and ensuring the transformation of resilient city goals.