基于GIS与Logistic模型的公路泥石流易发性分析

分析了泥石流形成与演化的物质条件、能量条件和环境条件。选取坡度、高程、坡面粗糙度、地层岩性、距断裂距离、地震烈度、土地利用类型作为泥石流易发性评价因子,引入Logistic回归分析方法,建立了泥石流易发性分析模型。定量分析了G318川藏公路段泥石流易发性,结果表明,该公路全线大部分处于泥石流中高易发区,其中,高易发区与中易发区占总面积的78.61%,主要分布在大渡河、澜沧江、金沙江、怒江、帕隆藏布江等大江大河的峡谷区段,这些地区在公路修复和规划重建中应做好泥石流的预测、预报及防治。

Evaluation Method of Debris-flow Susceptibility Using GIS and Logistic Model

The formation conditions of debris flow were analyzed and the seven key indexes of hill slope, elevation, hill surface roughness, rock stratum, distance to faults, seismic intensity of earthquake and land use type were chosen for evaluating the susceptibility of debris flow. A model of debris flow susceptibility was established by introducing logistic regression, and the evaluation and mapping of debris flow susceptibility were completed for the highways. Subsequently, this proposed method was applied in a case study carried out on the Sichuan-Tibet section of national highway G318. Analysis of debris flow susceptibility for the whole highway showed that 78.61% of the total study area was situated in debris flow-prone areas, including the canyon areas of Dadu, Lanchang, Jinsha, Nu and Palongzangbu Rivers. It is suggested that sufficient attentions should be paid in debris flow forecast and prevention in road reconstruction and line selection for new highway.