鹤庆盆地东缘古滑坡遥感识别与特征研究

Ancient Landslide Identification and Characteristics Using Remote Sensing along Eastern Edge of the Heqing Basin

古滑坡的识别与研究对认识区域地质构造、古气候、古环境的演变及其和人类社会发展的关系具有重要意义。基于遥感图像的纹理、色调特征等古滑坡解译标志,识别出鹤庆盆地东缘存在的两处古滑坡;同时,结合利用滑坡区数字高程模型(DEM)数据的滑坡地表形态分析,解译出两处古滑坡的位置、范围、前后缘高程等特征信息。利用GIS几何形态计算的结果表明,两处古滑坡规模分别达到1.30亿m3和5.64亿m3,属于巨型滑坡。综合滑坡区地层岩性、地质构造、地表覆盖特征及古地震活动分析,推测两处古滑坡均为地震所引发。对比分析古滑坡与大丽铁路、鹤庆火车站的相对位置关系,认为大型线性工程的选址不仅要着重目前区域稳定性的评价,还应考虑古地震次生地质灾害的影响范围和地震活动周期性,避让陡峭的断陷盆地边缘部位。

Large ancient landslides offer clues to the regional tectonics,climate change and paleoenvironment evolution that would be able to influence the development of human society in the future.It is difficult to identify ancient landslides,but with the development of remote sensing technology,it can be used to effectively recog-nize ancient landslides.Based on the image texture,tone characteristics,two ancient landslides have been identified by using the digital landslide technical method along the eastern margin of the Heqing Basin.The in-formation of these ancient landslides’features,such as the location,extent and elevation was extracted.The cal-culation results show that the two ancient landslides’scales reached 130 million and 564 million m3 ,respective-ly.The lithology,geological structure,stratigraphy covering relation and ancient seismic activity of the study ar-ea were analyzed in detail,suggesting that the two ancient landslides were triggered by powerful earthquakes. By comparative analyzing the relative position of the two ancient landslides with the Dali-Lijiang railway and the Heqing railway station,it was concluded that the construction of large linear projects should not only focus on the current regional stability evaluation,but also consider the ancient seismic activity,especially avoiding steep fault along basin edges.