• Long-term surface deformation was derived across 32 county-level cities. • A method was developed to link InSAR deformation with building damage intensity. • Groundwater extraction caused widespread uniform urban subsidence. • The method supports building deformation risk assessment and management. Groundwater exploitation has intensified land subsidence risks, yet spatiotemporal pattern of county-level surface deformation and their implications for potential building damage in resource-based arid urban agglomerations remain poorly understood. Here, long-term surface deformation across 32 counties within the Hohhot-Baotou-Ordos-Yulin (HBOY) urban agglomeration is derived by multi-temporal InSAR from ALOS-1/PALSAR and Sentinel-1A SAR imagery. A building-level potential damage assessment method is developed to bridge the gap between InSAR-derived deformation and building risk. It links and aggregates deformation points to building footprints and applies a standardized matrix to assign building damage intensity levels. Median subsidence velocities exceeding 3 mm/year were detected in three cities during 2007–2011 and increased to seven cities during 2018–2022. Hohhot was subjected to the most severe surface subsidence, with median velocities of −6.6 mm/year and −5.9 mm/year measured in the two periods. Surface subsidence in all cities has predominantly exhibited a uniform pattern, which is largely attributed to regional groundwater extraction. In addition, the heterogeneity of surface subsidence among cities is controlled by geological lithology, soil texture and the thickness of compressible layers. Despite widespread subsidence, most buildings in HBOY were classified as low damage intensity. The proportion of buildings with high or extremely-high damage intensity decreased from 3.03% to 2.27% between the two study phases, mainly associated with subsidence funnels and differential deformation linked to residual subsidence of high-rise buildings on compressible soils. These findings can provide critical support for targeted urban subsidence management and sustainable development.
Wang et al. (Sun,) studied this question.