Characteristics and influencing factors of rainfall-induced landslide and debris flow hazards in Shaanxi Province, China

摘要

Shaanxi Province, located in northwest China and spanning multiplehydroclimatic and geological zones, has many areas largely suffering fromrainfall-induced landslide and debris flow. The objectives of this study areto reveal the spatiotemporal characteristics of the two hazards and identifytheir major controlling factors in this region based on a region-wide,comprehensive ground-survey-based hazard inventory dataset from?2009 to 2012.We investigated the spatiotemporal characteristics of the two hazards andquantified the relationships between the occurrence rates of the two hazardsand their influencing factors, including antecedent rainfall amount, rainfallduration, rainfall intensity, terrain slope, land cover type and soil type.The results show that landslide has a higher occurrence rate and moreextensive distribution than debris flow in this region, while the two hazardsare both concentrated in the south with ample rainfall and steep terrains.Both of the hazards show clear seasonalities: July–September for landslideand July for debris flow. Rainfall characteristics (amount, duration andintensity) and slope are the dominant factors controlling slope stabilityacross this region. Debris flow is more sensitive to these rainfall metricson the high-value ranges than landslide in this region. Land cover is anotherinfluencing factor but soil type does not appear to impose consistent impactson the occurrence of the two hazards. This study not only providesimportant inventory data for studying the landslide and debris flow hazardsbut also adds valuable information for modeling and predicting the twohazards to enhance resilience to these hazards in this region.