大型岩质滑坡形变历史回溯及其启示

Tracking the Deformation History of Large-Scale Rocky Landslides and Its Enlightenment

大型岩质滑坡一般具有高位、隐蔽性强、高速远程等特点,往往造成严重的人员伤亡和财产损失。揭示其形变历史和发展演化规律,可以为类似滑坡灾害的早期识别提供参考。收集了近年来发生在中国大陆的5处典型大规模岩质滑坡滑前的多时相高精度遥感影像,通过对多时相高精度遥感影像的目视解译,对其形变迹象进行识别,并对其发展演化规律进行分析。发现大型岩质滑坡在发育演化过程中均会产生显著的地表变形迹象,这些形变信息可利用高分辨率光学遥感影像(亚米级)进行识别,变形的孕育演化时间可达数年甚至数10 a。大型岩质滑坡往往不具备"圈椅状"地貌特征,利用光学遥感影像对其早期识别的标志主要为坡体后源是否存在拉裂缝和坡体前缘是否存在局部滑塌。

Large-scale rocky landslides usually have the characteristics of high-altitude,strong concealment,high-speed and long-runout,which often lead to serious casualties and property losses.Revealing its deformation history and evolution rules can provide a reference for early detection of similar landslide disasters.Five typical large-scale rocky landslides in China in recent years are collected.Through visual interpretation of multi-temporal high-resolution remote sensing images,their deformation signs are identified and their evolution rules are analyzed.It is found that large-scale rocky landslides will produce significant surface deformation signs in the process of development and evolution.This deformation information can be identified by high-resolution(sub-meter level)optical remote sensing images.The incubation and evolution time of deformation can reach several years or even decades.Large-scale rocky landslides often do not have the'chair-like'geomorphological characteristics.The early identification signs of the landslides using optical remote sensing images are mainly whether there are tension cracks at the back of the slope and whether there are local slides at the front of the slope.