11:30 AM - 11:45 AM
[STT39-04] Observation of Landslides in the High Himalayan region of Lamjung District, Nepal, based on D-InSAR Analysis
Keywords:PALSAR-2, Nepal, Landslide
In Nepal, which has one of the world's largest landslide areas, field observation is difficult due to the highly undulating terrain, and monitoring and early detection of landslides are an issue. D-InSAR (Differential Interferometric SAR) is a technique to measure the ground surface deformation by irradiating microwaves twice from an antenna and measuring the phase difference between them.
Usami et al. (2021) detected two landslides (Fig.2; Site1, Site2) on the right bank of the Marsyangdi River in Nepal using PALSAR-2 data , and succeeded in long-term observation for four years. The landslides were successfully observed for four years. However, the distribution of landslides in the tributaries of the Marsyangdi River has not been clarified, and it is necessary to map the landslide distribution in a wider area. In Nepal, where the number of observed landslides is limited, there are few examples of studies that compare the amount of landslide deformation at multiple locations and discuss their regional characteristics. In this study, we extended the area of the study by Usami et al. (2021) to detect landslides and observe their deformation in a wide area. The PALSAR-2 data used in this study were taken from August 13, 2015 to December 26, 2019 in a North-Right direction.
As a result of reading the D-InSAR images, a landslide-induced phase change was detected at Khudi khola (river), a tributary of the Marsyangdi River (Fig.2; Site3). In this area, Gallo and Lavé (2014) reported the occurrence of a slope failure, and it was found that the landslide deformation area was wider than the area where the slope failure occurred. In addition, the detected landslide deformation is continuing and needs to be continuously monitored in the future.
Acknowledgement
This study was supported by KAKEN 19H01368, and data used in this study were provided by PIXEL (PALSAR Interferometry Consortium to Study our Evolving Land surface) under a cooperative research (2021-B-03) contract with ERI, Univ. of Tokyo. AW3D data (https://www.aw3d.jp/) were used for producing shaded relief map.
Reference:
Usami, S., Sato, H.P. and Yagi, H. (2021) Landslide and its displacement along the Marsyangdi river, Nepal detected by differential interferometric SAR. Japan Geoscience Union Meeting 2021, STT36-03.
Gallo, F. and Lavé, J. (2014) Evolution of a large landslide in the high himalaya of central Nepal during the last half-century. Geomorphology, 233, 20-32, DOI: 10.1016/j.geomorph.2014.06.021.
Usami et al. (2021) detected two landslides (Fig.2; Site1, Site2) on the right bank of the Marsyangdi River in Nepal using PALSAR-2 data , and succeeded in long-term observation for four years. The landslides were successfully observed for four years. However, the distribution of landslides in the tributaries of the Marsyangdi River has not been clarified, and it is necessary to map the landslide distribution in a wider area. In Nepal, where the number of observed landslides is limited, there are few examples of studies that compare the amount of landslide deformation at multiple locations and discuss their regional characteristics. In this study, we extended the area of the study by Usami et al. (2021) to detect landslides and observe their deformation in a wide area. The PALSAR-2 data used in this study were taken from August 13, 2015 to December 26, 2019 in a North-Right direction.
As a result of reading the D-InSAR images, a landslide-induced phase change was detected at Khudi khola (river), a tributary of the Marsyangdi River (Fig.2; Site3). In this area, Gallo and Lavé (2014) reported the occurrence of a slope failure, and it was found that the landslide deformation area was wider than the area where the slope failure occurred. In addition, the detected landslide deformation is continuing and needs to be continuously monitored in the future.
Acknowledgement
This study was supported by KAKEN 19H01368, and data used in this study were provided by PIXEL (PALSAR Interferometry Consortium to Study our Evolving Land surface) under a cooperative research (2021-B-03) contract with ERI, Univ. of Tokyo. AW3D data (https://www.aw3d.jp/) were used for producing shaded relief map.
Reference:
Usami, S., Sato, H.P. and Yagi, H. (2021) Landslide and its displacement along the Marsyangdi river, Nepal detected by differential interferometric SAR. Japan Geoscience Union Meeting 2021, STT36-03.
Gallo, F. and Lavé, J. (2014) Evolution of a large landslide in the high himalaya of central Nepal during the last half-century. Geomorphology, 233, 20-32, DOI: 10.1016/j.geomorph.2014.06.021.