Evolution Characteristics and Cause Analysis of Ground Subsidence in Sanhe City, Hebei Province, Based on SBAS-InSAR Technology

According to studies by relevant scholars, the ground subsidence rate in Sanhe City, Hebei, increased gradually from 2003 to 2016, with the most severe subsidence observed in the Yanjiao area , which has become contiguous with the subsidence area in Tongzhou, Beijing. However, the development trend of ground subsidence disasters in Sanhe City after 2016 remains unclear. With the implementation of national policies such as the integration of Beijing-Tianjin-Hebei region and the construction of Beijing’s sub-center, it is crucial to identify the development and evolution characteristics of land subsidence disasters in Sanhe City and analyze their causes to ensure the urban safety and sustainable development of Sanhe City. In this context, the authors used SBAS-InSAR technology to interpret the evolution characteristics of ground subsidence in Sanhe City from 2018 to 2020, and analyzed several inducing factors that led to land subsidence in Sanhe City, summarizing the main causes. Through this study, the spatial distribution and evolutionary characteristics of land subsidence disasters in Sanhe City were grasped: the western part of the city exhibits severe subsidence, while the eastern part is less affected, with a focus on the overall characteristics of key subsidence areas. Two main subsidence areas were identified, namely, the Yanjiao Town subsidence area with three subsidence funnels and the DuanJialing town subsidence area with one subsidence funnel, with the former being the most severely affected. From 2018 to 2020, the overall trend of ground subsidence disasters in Sanhe City showed a slowdown. Through comparative analysis, it was determined that severe overexploitation of groundwater, soil properties, urbanization development, and population growth are the main factors contributing to the occurrence and development of ground subsidence disasters in Sanhe City. The research results of this paper will provide reference for the prevention and control of ground subsidence disasters in the region.