CLOSE RANGE DIGITAL PHOTOGRAMMETRY APPLIED TO TOPOGRAPHY AND LANDSLIDE MEASUREMENTS
- 1Department of Civil and Disaster Prevention Engineering, National United University, Miaoli 36063, Taiwan
- 2Taiwan Typhoon and Flood Research Institute, National Applied Research Laboratories, Taipei 10093, Taiwan
- 3Ph.D. Program in Materials and Chemical Engineering, National United University, Miaoli 36063, Taiwan
Keywords: Close range; photogrammetry, Direct linear transformation, Topography, Landslide, Image matching, Huoyen Shan
Abstract. Landslide monitoring is a crucial tool for the prevention of hazards. It is often the only solution for the survey and the early-warning of large landslides cannot be stabilized. The objective of present study is to use a low-cost image system to monitor the active landslides. We adopted the direct linear transformation (DLT) method in close range digital photogrammetry to measure terrain of landslide at the Huoyen Shan, Miaoli of central Taiwan and to compare measured results with e-GPS. The results revealed that the relative error in surface area was approximately 1.7% as comparing the photogrammetry with DLT method and e-GPS measurement. It showed that the close range digital photogrammetry with DLT method had the availability and capability to measure the landslides. The same methodology was then applied to measure the terrain before landslide and after landslide in the study area. The digital terrain model (DTM) was established and then was used to calculate the volume of the terrain before landslide and after landslide. The volume difference before and after landslides was 994.16 m3.