Risk management of land subsidence in Shanghai

Abstract

Land subsidence resulting from over-exploited groundwater has become a leading factor restricting the sustainable development of resources, environment, and economy in Shanghai. To design management plans to control the environment geology calamity problems arisen by land subsidence effectively, this research constructed risk index system on the basis of risk source identification of subsidence and then established risk assessment model. The risk index system is composed of hazardous conditions and vulnerability of land subsidence. Results from comprehensive consideration of the model calculations, subsidence distribution and local socio-economic trends showed that the controlling district of land subsidence in Shanghai can be divided into three subsidence—primary control zone (Zone Ⅰ), second control zone (Zone II), and normal control district (Zone III), corresponding with a high, moderate, low subsidence risk, respectively. On the basis of Shanghai urban and rural planning, the control target scheme of land subsidence with each zone in the future, different groundwater, resources management schemes are put forward, which mainly refer to control groundwater exploitation, to perform artificial recharge and to strengthen construction of recharge wells.