Abstract:
Since the late 1950s,Xi'an City has suffered from serious land subsidence and ground fissure,which seriously restricted the urban construction and development planning of Xi'an City. In this study,Yuhua Village,one of the typical land subsidence areas in Xi'an City,was taken as the research area. Based on the SBAS-InSAR technique,ERS(1992-1993),Envisat(2003-2010) and Sentinel-1A(2015-2020)satellite datas covering the study area are used to analyze the temporal and spatial evolution characteristics of land subsidence and ground fissures in the surrounding area of Yuhua Village. The drilling data and the history and current situation of groundwater exploitation and urban development are used in this paper. The genetic mechanism of land subsidence and ground fissures in the study area is also discussed. The main conclusions of this study are as follows. (1)The annual average subsidence rate of three stages in the surrounding area of Yuhua Village from 1992 to 2020 is obtained,which reveals that the subsidence center changes from the Electronic City(90mm ·a
-1)in the 1990s to the present Yuhua Village(50mm ·a
-1). (2)It is confirmed that there is a correlation between the land subsidence and the ground fissure in the temporal and spatial distribution. The ground fissures develop in the north edge of the land subsidence trough,which limit the northward development of land subsidence trough. And the ground fissures extend with the development of the land subsidence trough. (3)It is revealed that the Yuhua Village subsidence center is still expanding,and the f4 ground fissure may extend westward. (4)The development of land subsidence and ground fissure around Yuhua Village is affected by the exploitation of underground confined aquifer and human construction activities. The above understanding can provide certain reference and support for urban land development and disaster prevention affected by land subsidence and ground fissures.