基于三维激光扫描仪的滑坡表面变形监测方法——以金坪子滑坡为例

Landslide monitoring by three-dimensional laser scanner-case study of the displacement detection of the Jinpingzi landslide(Southwest,China)

近年来,三维激光扫描仪越来越多地被应用于滑坡变形监测领域以降低或减少滑坡灾害带来的风险。本文以云南省乌东德地区金坪子滑坡为例,运用三维激光扫描仪监测技术对处在库区的金坪子滑坡表面变形进行了监测与研究。传统的监测数据显示,该滑坡正以每年约30cm的高速度向前推动,运动的结果可能危及周边居民的人身财产安全以及乌东德水电站的运营。研究中激光扫描数据集由高精度和高密度的三维点云组成,分别从6个站点、3次采集得到,时间跨度25个月(从2009年5月~2011年7月)。滑坡表面变形通过按时间序列排列扫描数据集的比较得出。通过采用三种方法,DEM(数字高程模型)比较,断面比较与固定点比较,分析已经过前处理的点云数据集,从而分析得到监测结果。此外,滑坡的变形量也计算得到。研究介绍了激光三维点云处理的流程,探讨了将三维激光扫描监测技术应用于大型、有部分植被覆盖的滑坡监测的可能性,并将监测结果分析与GIS平台结合起来,结果帮助我们大概地、基本地对滑坡稳定性做出评价。三维激光扫描监测滑坡变形的应用为我们在存在高风险的大型滑坡变形监测提供了另一种直观和高效的方式。

The three-dimensional laser scanner is frequently applied to the deformation monitoring for landslide risk reduction in recent years. This case study deals with a landslide face deformation monitoring in the reservoir area. According to the traditional monitoring data,this landslide is on a high level of movement with about 30 centimeters per year,which may endanger the safe construction and operation of Wudongde hydropower station,Yunnan Province( Southeast China). The laser scanning datasets consist of high solution and high density 3D point clouds which were acquired from six stations,three times during a time period of 25 months( from May 2009 to July 2011). Deformation was detected by means of comparison of sequential scanning datasets. Three approaches,comparison of DEM( Digital Elevation Model),section and fixed point,have been adopted to analyze the pre-processed datasets. Also,the deformation volume of the landslide is computed. In this paper,the process of data computation was introduced,and the possibility of the application of three-dimensional laser scanning monitoring technology to large,partly vegetationcovered landslides was discussed. The post-process and analysis of data were performed on GIS platform. Our results enable us evaluate the stability of the landslide generally and basically. The application of three-dimensional laser scanning to monitoring landslide deformation provides us another considerably effective and efficient way in the highrisk landslide deformation monitoring.