基于遥感技术的嘉黎江巴变形体稳定性评价与分析

Stability evaluation and analysis of the Jiangba deformed body in Jiali County based on remote sensing technology

江巴变形体位于西藏嘉黎县尼屋乡江巴村下游约5 km处的易贡藏布右岸,遥感影像中可见多处地表崩滑痕迹,存在山体不稳定、发生崩滑堵江的威胁。为了查明该坡体的稳定性、整体变形特征以及可能存在的灾害威胁,达到提前预防、未雨绸缪的目的,采用“多期次影像遥感解译监测+InSAR形变分析+现场调查”的综合研究评价方法,对该变形体坡面进行了详细的解译分析,显示变形体目前处于“整体稳定、局部崩滑”状态。近年来变形体范围边界未发生明显变化,在其南侧及东侧坡脚区域发生过多期次小规模崩滑现象,在外部环境变化影响下,变形体中上部仍然存在高位崩塌-碎屑流的可能。

The Jiangba deformed body is located approximately 5 km downstream of Jiangba village,Niwu Township,Jiali County,Tibet,on the right bank of Yigong Zangbo.Multiple surface avalanche traces are visible in the remote sensing images,and there is a threat of landslides and river blockage due to the instability of the mountain.There is an urgent need to identify the stability of the slope,the overall deformation characteristics and possible disaster threats to achieve the purpose of early prevention and plan ahead.In this study,a comprehensive research and evaluation method of"multistage image remote sensing interpretation monitoring+InSAR deformation analysis+field investigation"was adopted to interpret and analyze the slope surface of the deformed body in detail,and it is shown that the deformed body is currently in a state of"overall stability and local collapse".In recent years,the boundary of the deformed body has not changed significantly,and many small-scale landslides have occurred in the southern and eastern slope foothills.Under the influence of external environmental changes,the possibility of high collapse-debris flow still exists in the middle and upper parts of the deformed body.