泥石流对岩性的敏感性分析及其在危险性评价中的应用

泥石流对不同岩性的敏感程度存在很大的差异，而岩性在泥石流相关的科学研究中也难以量化使用。本研究选择三江并流区为研究区，采用工程地质岩组划分方法，将研究区的地质岩性分为14个工程地质岩组；进而引入岩性敏感度计算公式Fn = Nn / Sn，分析研究区泥石流灾害点分布与地质岩组的相关性，计算出泥石流对各地质岩组的敏感值。在ArcGIS 90平台的支持下，根据泥石流对岩性的敏感值，将研究区的地质岩性进行量化分级，划分为4个敏感性等级，并将本研究成果应用到三江并流区泥石流危险性评价的应用中。本文选择坡度、岩性、断裂、植被和人类工程活动等5个影响因子为泥石流危险性的评价指标，建立泥石流危险性评价模型，在GIS技术支持下，绘制研究区的泥石流危险性区划图。本研究结果与研究区已有的地质灾害点分布情况基本吻合，充分证明本研究方法是切实可行的，进而可为我国西南地区的地质灾害评价以及防灾减灾工作提供方法指导与参考

SENSITIVITY ANALYSIS TO LITHOLOGY AND APPLICATION IN RISK ASSESSMENT OF DEBRIS FLOW

The sensitivity of debris flow to different lithology is significantly different,and the rock is difficult to use in debris-related research quantitatively.Taking the Three Rivers Parallel Area as the study area,the lithology is divided into 14 engineering geological rock groups by using the division method.By introducting the lithology sensitivity formula Fn = Nn / Sn,the relationship between debris flows and rock groups in the study area is analyzed,and the sensitivity of debris flow to the rock groups is calculated.Supported by ArcGIS 9.0,the lithology is classified into 4 levels according to the sensitivity,and the classification results are applied to the risk assessment of debris flow in the study area.The paper chooses slope,lithology,fracture,vegetation and human activity as debris flow risk evaluations,establishes the debris flow risk assessment model,and obtains the hazard zonation map of the study area in support of GIS technology.The results coincides with the actual disasters,fully proving that this methodology is feasible,which can provide guidance and reference for geological hazard assessment,disaster prevention and mitigation in Southwest China.