Quantitative Debris Flow-Induced Vulnerability Assessment

Abstract

Debris flows are rapid and destructive mass movements that pose severe threats to infrastructure and human settlements in mountainous regions. Although hazard intensity and spatial susceptibility have been widely investigated in previous studies, quantitative assessments of physical vulnerability remain comparatively underexplored. In this study, a quantitative analysis for building vulnerability to debris flow impacts was developed, with explicit consideration of building types. Two broad categories were assessed: reinforced concrete (RC) frame structures and non-RC frame structures, including wood, lightweight steel, and unreinforced brick masonry. The analysis demonstrates that non-RC frame structures exhibit markedly higher susceptibility to debris flow impacts, frequently resulting in severe structural damage or complete collapse. Conversely, RC frame structures display considerably greater resistance, with outcomes generally limited to minor damage or no structural impairment. The NVI comparison (53.9 observed vs. 66.3 predicted) demonstrates generally consistent results, with the model exhibiting a slight conservative bias. This reliability strengthens its usefulness for risk assessment, disaster mitigation, and resilient land-use planning in debris flow-prone regions.