Numerical study on evolution of groundwater hydrodynamics and land subsidence under the process of metropolitan urbanization in Beijing Plain, China

Ground subsidence in Beijing has a history of more than 60 years, which has close relationship with the rapid expansion of Beijing City in the past half a century. In this paper, based on the groundwater flow system of the entire Beijing Plain, a large amount of data of urban development scale, population, and water dynamics over a multi-year time series (1950s-2015s) has been combed, and the impervious covers of the Beijing Plain in different years are interpreted so as to analyzes the changes of rainfall infiltrations into groundwater systems by using remote sensing technology.After generalized a three-dimensional aquifer-aquitard structural system in the entire plain, a regional model coupling multi- groundwater flow with land subsidence model with PMWIN software, which is identified and verified by converging long-term water level and subsidence observation data. Long-term evolution simulation of groundwater hydrodynamics and land subsidence have been performed to study the evolution of the water cycle and the response characteristics of land subsidence in a multi-layer aquifer system in the Beijing Plain under rapid urbanization.The results show that the long-term evolution simulation coupling groundwater flow and land subsidence basically reproduces the process of formation and development of land subsidence.The history of groundwater abstraction in Beijing City is consistent with the history of land subsidence development. Moreover, the land subsidence developments in different subsidence areas are mainly controlled by groundwater abstraction and metropolitan urban development.