辽宁暴雨诱发山洪灾害风险区划研究

基于自然灾害风险评估理论，利用2005—2019年辽宁省1639个自动站逐时降水观测资料、2017年辽宁省30 m分辨率的基础地理信息和山洪沟资料以及风险普查数据，对辽宁暴雨诱发山洪灾害风险区划进行研究，并将风险区划结果与历史山洪灾情进行对比分析。结果表明：通过山洪灾害与降水相关性统计发现，6 h暴雨作为辽宁省山洪致灾因子更为合适，因此构建了6 h综合利用分级暴雨强度及暴雨频次精细评估暴雨致灾危险性；山洪沟沟口高程、沟床比降及河网密度等资料可有效评估山洪孕灾环境敏感性；人口密度、耕地比例两个风险暴露度指标以及灾损敏感系数可大体评估承灾体的易损性；与历史山洪灾害空间和频率分布对比，山洪灾害的高发区与在本次风险区划高风险区基本吻合；精确到每个山洪沟风险区划的结果，提高了山洪灾害的风险区划精度，为辽宁暴雨诱发山洪灾害精准防御提供参考。

Research on the risk zoning of mountain torrent disasters induced by torrential rain in Liaoning province

Based on the natural disaster risk assessment theory, this paper uses the hourly precipitation observation data of 1639 automatic stations from 2005 to 2019, the basic geographic information with a resolution of 30 m of Liaoning province in 2017, and the data of mountain torrents to study the risk zoning of mountain torrent disasters induced by heavy rain.The results of risk zoning are compared with the historical flash floods.The results show that through the statistics of the correlation between mountain torrent disasters and precipitation, the 6-hour rainstorm is more suitable as the disaster-causing factor of mountain torrents in Liaoning province.Therefore, a 6-hour comprehensive utilization classification of rainstorm intensity and rainstorm frequency is constructed to finely evaluate the disaster risk of a rainstorm.Data such as elevation of mountain torrent gully, ditch-bed gradient, and river network density can effectively evaluate the environmental sensitivity of mountain torrent disasters.The two risk exposure indicators of population density and cultivated land ratio, as well as the disaster sensitivity coefficient, can generally evaluate the vulnerability of disaster-bearing bodies.Compared with the spatial and frequency distribution of the historical mountain torrent disasters, the high-incidence areas of mountain torrent disasters are consistent with the high-risk areas in this risk zoning.Based on the accurate risk zoning results of each mountain torrent gully, the risk zoning accuracy of mountain torrent disasters has been improved.It provides a valuable reference for the precise defense of induced flash flood disasters.