Research on evolution of land subsidence induced by nature and human activity by utilizing remote sensing technology

In Northern China, main water supply is groundwater. In recent years, as the city's construction and development, long-term over-exploitation of groundwater has induced land subsidence which endangers the safety of human lives and properties. Because Beijing is a region seriously lack of water, five water sources for emergent events were built in order to meet the demand for urban water supply. Groundwater in such sources has been exploited in large-scale, high-intensity and concentratively, which will change groundwater system and result in related environmental-induced geological disasters. Shunyi District, as the place in which China's largest and most advanced Capital International Airport locates, meets more and more geological disasters such as land subsidence and ground fissure. Nature-human coupled factors impact on land subsidence progressing is focused in Shunyi District, the selected study area in this research. In the study, multi-scale remotely sensed imageries are utilized to extract human activity impact factors, especially in built-up areas. Hydrologic data is collected, and precipitation is defined as one of the natural factors. Comparison is made on relations between intensity change of accumulative ground subsidence and factors including precipitation, shallow groundwater exploitation amount, and land use in the period of 1990 to 2006. Meanwhile, contribution of nature-human impact factors on land subsidence is determined by AHP, and a Grey model is constructed in this research to forecast the intensity of ground subsidence in order to provide reference for prevention, control and slowdown on land subsidence.