A New Method for Regional Assessment and Risk Mapping of Ground Fissure Activity Intensity: Evidence from the Longest Ground Fissure in China

Basin-margin transition zones in northern China commonly host large scale ground fissure systems driven by intense tectonic deformation and human activities， while land deformation induced by ongoing groundwater overpumping has become a key driver sustaining their continued activity. Such widespread surface cracking has caused substantial losses to local economies and ecosystems. Therefore， accurate modeling and dynamic characterization of activity intensity in ground fissure zone are essential for elucidating spatiotemporal evolution and for directly informing risk zone delineation， urban risk management， and land use planning. However， quantifying ground fissure activity intensity remains challenging because disaster geometries are irregular and activity is both gradual and highly variable. Focusing on the Jiaocheng ground fissure at the margin of the Taiyuan Basin， China， we propose a framework that integrates field investigations with Interferometric synthetic aperture radar （InSAR） derived ground deformation to characterize interannual ground fissure activity intensity. We quantify activity intensity for 2016-2024 and classify risk levels within the disaster affected area using the multi-year mean activity intensity of the tensile failure domain as a threshold. Results show that （1） 745 disaster points were identified， and the Jiaocheng ground fissure zone currently extends 54 km， with a maximum affected width of 6 km and a total affected area of 206 km²; disasters exhibit pronounced belt-like and segmented spatial patterns， and activity intensity decreases with increasing axial width. （2） During 2016-2024， high-risk zones account for 13%-18% of the affected area and， together with activity intensity， display spatial clustering of high values; temporally， they evolve through an “abrupt intensification-high level fluctuation-rapid decline” trajectory. （3） Exposed objects within risk zones are dominated by cropland and impervious surfaces， and the exposure structure progressively concentrates toward cropland and urban land in later years.