Surface subsidence and ground fissures activity monitoring based on D-InSAR: A case of Datong city

The Synthetic Aperture Radar Interferometry technique has become one of geological disaster monitoring tools, for its economical, efficient, high-precision and large-scale surface deformation monitoring capacities. Datong is a well-known historical and cultural city, which is also a major energy bases and known as ldquotown of coal seardquo reputation in China. Since 1980s, with the development of industry and agriculture the amplitude of groundwater withdrawal has increased year by year, which lead to serious surface subsidence and ground fissures hazards in this city, even active up-to-date. Presently, 10 ground fissures with a total length of 34.5 km can be found in Datong region. However, the city-level spirit leveling only carried out during years of 1988-1993 to monitor the surface subsidence, and ceased later on. So in this paper, we collect 8 scenes of Envisat SAR data covering Datong city to minitor the subsidence evolution during Jan. 2005 to Feb. 2008. The interferometric pairs are set according to the principles that temporal and geometric baseline limits. Finally, we obtain the annual and accumulated subsidence amounts. The study shows that the land subsidences in Datong are greatly correlated with the groundwater withdrawal and seasonal variation. And some new sobsidence cones are located at new economic and technological development zones of Datong city. Thirdly, ground fissures deformation in Datong is controlled by the regional tectonic activity and also affects the land subsidence in its surroundings.