Characteristics and trends of land subsidence in Tanggu, Tianjin, China

Land subsidence in the Tanggu area is directly related to withdrawal of shallow ground-water within a depth of 300 m. The main strata responsible for the subsidence are at a depth of between 136 and 300 m. The contribution to subsidence made by the clayey soils is dierent from that of the sandy soils, as the former is related to the seasonal dropping of the water table while the latter is associated with annual changes. In addition, while there is a clear correlation between the accumulative groundwater extraction and the accumulative subsidence, this linear relationship is not obvious between annual extraction and annual subsidence. A case study in Tanggu, Tianjin, is presented in order to demonstrate a proposed computational model to predict land subsidence - the Optimization Model for Land Subsidence (OMLS).link_to_subscribed_fulltex