三峡水库区城镇滑坡分布及发育规律  

Landslide distribution and development in the towns of the Three Gorges Reservior area

作　　者：王治华[1] 

机构地区：[1]中国国土资源航空物探遥感中心,北京100083

出　　处：《中国地质灾害与防治学报》2007年第1期33-38,共6页The Chinese Journal of Geological Hazard and Control

摘　　要：以2003年3月的115万航片为主要遥感信息源，1/1万地形图为地理控制信息源；采用“数字滑坡”技术方法在三峡水库区中前段8个城镇调查区获取了投影面积大于1000m^2的826个滑坡的分布及其发育环境的基本信息。分析表明各调查区滑坡分布的平均地面密度有较大差异。其中大坝一秭归调查区最低，约1．6‰，巴东、奉节区滑坡分布地面密度最大，分别达到8．0％、7．6％；各区滑坡均有明显的集中密集分布特点。巫山县北岸为调查区滑坡分布线密度最大的岸坡；滑坡堆积的后前缘在海拔970—65m范围，区域滑坡分布最高高程与该区的地势相应，前缘最低高程与该处最低侵蚀基准面相当。本区80％以上的滑坡分布在海拔400-100m——人类活动最强烈的高程范围。滑坡分布特征揭示地层是控制三峡水库区中前段滑坡发育的最重要的地质环境因素。提出“易滑指数-ES”和“区域易滑指数-RES”概念，以此说明区内各地层易于发育滑坡的程度及其分布比例。三叠系中统巴东组T2b和侏罗系沙溪庙组J2s为调查区分布最广、发育滑坡最多、滑坡平均规模最大的易滑地层。构造对滑坡分布的控制作用表现在当褶皱构造走向与江河走向一致时，滑坡大部发育在顺层坡，特别是近轴部位置；当褶皱与江河斜交时，其对滑坡分布的控制作用不明显。滑坡前缘分布持征表明江河侵蚀是诱发本区滑坡的重要因素。三峡水库蓄水后侵蚀条件改变，滑坡活动将增加，其大部分由人类不合理活动诱发。Take 1 ： 10,000 ortho-image made from 1：50,000 aero-photo taken in March, 2003 as the remote sensing data, and digital 1：10,000 topography map as the geographic coordinate control, by using the ＂digital landslide＂ technique the basic information of distribution and developing geological environment of 826 landslides, each area larger than 1000m^2, in the eight study areas in front half part of the Three Gorges Reservoir of Yangtze River has been obtained. The landslide distribution density is so different in each area that it is only 1.6%0 in the head part of the Three Gorge Reservoir and it reaches 8% and 7.6% in Badong and Fengjie area. The back and front edge of the landslide body in all of the study area is in the limitation of 970 - 65m above sea level. The highest elevation for the landslides distribution are correspond to the hypsography of the region, and lowest to the river erosion level. Over 80 % landslide in the area distribute in the elevation of 100- 400m above sea level where human being activities frequency. The study revealed that the lithology layer is the most important factor of geological environment for controlling landslide distribution, and ＂Easy Sliding＂ index-ES and ＂Regional Easy Sliding＂ index-RES are proposed to illustrate the capacity of landslide development in each litho logic layer. The study show that the middle Triassic Badong Group clay, sand, limestone and shale interbedding-T2 b and middle Jurassic Shaximiao Group clay, sand stone interbedding-J2 s are the two most important layers that widely distributes in most of the study area, and with the biggest average volume of regional landslides. Fold is the major tectonic form of the study area. When the strike line of the fold is parallel to the river, landslides most develop in the consequent slope, especially near the fold axes place. While the folds strike obliqine cross the river it has no obvious effect on controlling landslide development. The front edge of the landslide distribution characteristics of

关 键 词：数字滑坡技术 三峡水库区中前段 滑坡分布 易滑地层 褶皱构造 

分 类 号：P642.22[天文地球—工程地质学]