Investigating Surface Deformation and Its Intrinsic Mechanism in Shenzhen, China Using Sentinel‐1A SAR Imagery

Abstract

Abstract To avoid disasters caused by surface deformation in urban areas, monitoring and analyzing the mechanism of surface deformation in urban areas on a large scale and in long‐term series is mandatory. Based on PS‐InSAR technology and using 157 Sentinel‐1A images, the surface deformation in Shenzhen was monitored from 2015 to 2022, and the obtained deformation rate ranged from −22.8 to +23.2 mm/year. In this paper, analysis is presented by integrating urbanization, climate, and geology data from Shenzhen. The analysis indicates that surface deformation caused by natural factors is typically observed in regions with unique geological characteristics, such as seasonal deformation in sedimentary areas and uplift along reverse fault zones. Human factors chiefly cause subsidence, and the areas with greater subsidence are generally urbanized areas (∼10 mm/year), industrial areas (∼20 mm/year), and reclamation areas (∼15 mm/year). The deformation of the reservoir dam is subject to multiple factors. The differential subsidence of 2–8 mm/year at both ends is due to the engineering geological conditions. In comparison, the weak rotation with a linear velocity of 18 mm/year is due to hydrostatic pressure and its structural characteristics. The research results of this paper systematically explore the phenomena and the intrinsic mechanism of surface deformation in Shenzhen, providing a safety basis for urban development and emergency disaster prevention in Shenzhen.

Keywords

• PS‐InSAR
• surface deformation
• engineering geology
• seasonal deformation
• reverse fault