Multi-spatial scale analysis of cutting-slope houses to landslide hazard in granite regions: A case study in central China

In landslide studies, vulnerable elements have received limited attention. In densely populated areas of China, slope cutting for house construction is widespread and significantly increases the risk of landslides behind houses, threatening both property and human safety. This problem is especially serious in China, where granite weathering crusts are widely distributed. Taking Yanling County as a case study, this study comprehensively investigated the current status and risks of cut-slope houses in granite areas. A total of 3,478 potential landslides were identified and 12,420 houses near slopes were sampled. A dataset was constructed using geological, geometric, and structural factors, and was combined with field surveys to support experiments and statistical analyses from the rock-soil scale to the regional scale. Results from 56 samples reveal significant granite strength degradation due to weathering. Analyses of three landslide cases and six slope units further clarify the characteristics of landslide hazards in the study area. Machine learning was used to assess the effects of multiple factors on landslide susceptibility and house vulnerability. Rainfall erosion showed a particularly strong effect on landslides in granite areas, distinguishing them from non-granite areas. For houses, slope-cutting height and distance from the slope toe were identified as the two most critical risk factors, as supported by both observed damage cases and regional-scale data mining. Two-dimensional thresholds were established to characterize the combined effects of these factors on disaster occurrence. Accordingly, three measures are recommended for landslide risk control in the study area: strengthening ecological restoration of granite slopes, moderately limiting slope-cutting height, and ensuring a sufficient safety distance from the slope toe during house construction.