Trial to Measure the Ground Surface Areal Displacement of Landslide Using Three-dimensional Laser Scanner
Abstract
When cracks or differences in level on a slope have occurred, which are considered as precursory phenomena of landslide, it is important to grasp range and size of the landslide immediately. In order to prevent damages, it is also important to evaluate the degree of hazard of the landslide end leading up to collapse. In general, cracks or differences in level appear around the head part of landslide at the beginning of its movement. On the other hand, in the toe or side part of landslide, deformed shape like cracks appear after the landslide mass moved in some extent. Therefore, it is difficult to decide the range of the landslide at an early stage of its movement. Furthermore, it is essential to grasp the transformation mechanism in the toe part of the landslide for evaluating the degree of hazard, but measurement method which can grasp areal displacement is not established. In order to address these problems, we have been developing the areal displacement measuring method using three-dimensional laser scanner, and estimating the collapse that will be occurred at the toe part of landslide. We have measured the topography of some landslide slopes in Japan using three-dimensional laser scanner. In addition, we have measured some reflection targets by total station each time for verification. And we tried to detect the areal displacement by differences of the time-lapse measurement data. The results are as follows: (1)Three-dimensional laser scanner can detect the areal displacement in a certain level of precision on the area covered with structures such as concrete frame works or on the bare ground as outcrop. (2)It is necessary to contrive ways to coordinate transformation of the acquired data. (3)It is necessary to study how to measure the ground surface covered with vegetation. In this presentation, we will show some analyzed results about some test field sites. Although there remain some future issues including (1) measurement and evaluation methods taking account of vegetation on the slope, (2) prediction method for dimensions of collapses at the toe of the slope, we will continue to study on those issues.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFMNH23A1426I
- Keywords:
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- 0468 BIOGEOSCIENCES / Natural hazards;
- 1810 HYDROLOGY / Debris flow and landslides;
- 1816 HYDROLOGY / Estimation and forecasting