贵州省黔东南州降雨型泥石流风险评估

利用贵州省黔东南州15个气象站1990—2019年逐日降水量、DEM、土地利用、常住人口等数据，采用层次分析法（AHP），从危险性和环境脆弱性两个方面构建降雨型泥石流风险评估模型，并采用历史泥石流事件对评估结果进行验证。结果表明：危险性指标中暴雨日数的重要程度最高，危险性的空间分布表现为西部和东部最高，北部最低；环境脆弱性指标中高程的重要程度最大，研究区的环境脆弱性整体上四周更高，中部较低。研究区降雨型泥石流极高风险区分布在最东部和西部，主要是由危险性最高造成；高和中度风险主要分布在南部地区，其中中度风险区是由脆弱性相对较低造成。历史泥石流灾害案例中有76.6%发生在极高和高风险区，风险评估结果与历史泥石流事件分布相吻合。

Risk assessment of rainfall induced debris flow in Qiandongnan Prefecture of Guizhou Province

Based on the daily rainfall, DEM, land use, and resident population data from 15 meteorological stations in Qiandongnan Prefecture, Guizhou Province from 1990 to 2019, a rainfall debris flow risk assessment model was constructed according to hazard and environmental vulnerability by analytic hierarchy process (AHP) and the assessment results was verified by using historical debris flow events. The results showed that among the hazard indicators, the importance of rainstorm days was the highest. The spatial distribution of hazard was the highest in the western and eastern region, with the lowest in the north. Among the environmental vulnerability indicators, the elevation was the most important. The environmental vulnerability of the study area was higher around and lower in the middle. The extremely high risk area of rainfall debris flow in the study area was concentrated in the east and west, which was mainly caused by the highest hazard. The high and medium risks were mainly distributed in the south, and the medium risk area was caused by relatively low vulnerability. About 76.6% of the historical debris flow disaster cases occurred in extremely high and high risk areas, and the risk assessment results were consistent with the distribution of historical debris flow events. The research conclusions can provide some guidance for the early warning and prevention of debris flow disaster in Qiandongnan Prefecture, Guizhou Province.