高烈度地震区路域成灾因子敏感性分析

Sensitivity analysis of road disaster factor in high seismic intensity canyon region

为了研究高烈度地震区公路走廊带地形条件震时对地质灾害的影响机理,找出路域地质灾害的主要地形成灾因子。以汶川地震汶川—理县灾区为研究区域,应用考虑特征值和贡献率的主成分分析理论,基于地理信息系统技术平台,选取地面高程、地表坡度、地表起伏度、地表粗糙度进行地质灾害成灾因子的主成分分析,并对各指标进行敏感性分析,确定了路域地形条件的主要成灾因子。分析结果表明:地表坡度和地面高程是汶川—理县地区地质灾害的主要地形成灾因子,其累积贡献率达到98.165%,第1主成分中地表坡度、地表起伏度和地表粗糙度主成分荷载为0.987,0.981和0.990,第2主成分中高程和地表坡度主成分荷载为0.987和0.089,以地表坡度的影响尤为突出。

In order to investigate the impact mechanism of terrain condition on geological disasters in high seis-mic intensity canyon region and find out the salient factor,Wenchuan -Lixian area was used as the study area. By applying the principal component analysis theory which consideres the characteristic value and the contribu-tion rate,using geographic information system as the technology platform,and adopting ground elevation,surface slope,surface waviness and roughness as the main factors,the principal component analysis was conducted.Mo-reover,sensitivity analysis was conducted to determine the main road area terrain conditions disaster factor.The results indicates that the surface slope and ground elevation are the key disaster factors to cause the geological disasters in Wenchuan -Lixian area,cumulative contribution rate is 98.165%,surface slope,principal com-ponent loading of surface waviness and surface roughness in the first principal component are 0.987,0.981, 0.990,principal component loading of ground elevation,surface slope in the second principal component are 0.987 and 0.089,and the influence of surface slope is particularly prominent.