Settlement Of Ground-based Three-dimensional Geological Body

In recent years, persistent drought has led to significant reduction in the contribution of precipitation to groundwater supply in Beijing. In order to meet the water demand of the city, multiple emergency groundwater sources were built for water supply scheduling. Large quantity of continuously groundwater exploitation activities cause dramatic decrease in groundwater level, result in cone of depression and lead to regional land subsidence. Geological lithology and structure are important background influencing factors for the land subsidence induced by excessive extraction of groundwater. Therefore, accurate characterization of the loose Quaternary stratigraphy and quantitative determination of influence of rock strata to land subsidence are important parts of the study on the mechanism of land subsidence.In this paper, we choose the up-middle part of the Chaobai River in Beijing as study area, borehole data and radar images as data source. Based on geostatistics, this research sought to mine the spatial structure and statistics information from borehole data and established the3D hydrogeological model by using the transition probability, spatial Markov Chain and condition simulation. Then GIS spatial analysis and statistical techniques combined with amount of cumulative settlements data acquired from PS-InSAR technology were applied to analyze the influence of strata’s lithology on land subsidence. The study results will be useful to the mechanism research of land subsidence.