Abstract
The April 25, 2015 MW 7.8 Nepal-Gorkha earthquake triggered thousands of landslides throughout the epicentral region. This research focuses on characterizing the distribution and patterns of earthquake induced landslides within the district of Sindhupalchok, which is located northeast of the capital city Kathmandu and suffered some of the most devastating cases of seismic slope instability.
By comparing pre- and post-earthquake high resolution satellite imagery, over 5,000 landslides have been documented in Sinduhupalchok. Approximately 70% are new landslides and 30% represent existing deposits that were reactivated during the earthquake. Data recorded for each landslide includes surface area, aspect ratio, elevation, slope angle and azimuth, and this information is combined with topographic, geologic and seismic datasets in a GIS framework to assess patterns and trends of occurrence. The compiled dataset shows landslides are concentrated between elevations of 1500 and 2500 meters, the surface area of landslides tends to increase with elevation, and landslides are more common on south to southeast sloping hillsides. Furthermore, landslide occurrence increases for slopes steeper than 350 and in shale and limestone formations. Within the major drainage basins of Sinduhupalchok, the maximum surface area affected by landsliding is approximately one percent, and approximately 75% of the documented landslides occur within 120 km of the M7.8 epicenter.
The compiled landslide inventory was calibrated and validated based on detailed observations made during two post-earthquake field investigations. The first investigation was performed from May 16 – 22, 2017, directly after the main earthquake shock and prior to the monsoon season. The follow up investigation was performed from October 16 – 22, 2017, directly after the monsoons. provides a detailed account of the performance of steep mountain terrain subjected to strong ground shaking, as well as valuable insights for assessing future seismic slope performance in Sinduhupalchok and neighboring districts of Nepal.
By comparing pre- and post-earthquake high resolution satellite imagery, over 5,000 landslides have been documented in Sinduhupalchok. Approximately 70% are new landslides and 30% represent existing deposits that were reactivated during the earthquake. Data recorded for each landslide includes surface area, aspect ratio, elevation, slope angle and azimuth, and this information is combined with topographic, geologic and seismic datasets in a GIS framework to assess patterns and trends of occurrence. The compiled dataset shows landslides are concentrated between elevations of 1500 and 2500 meters, the surface area of landslides tends to increase with elevation, and landslides are more common on south to southeast sloping hillsides. Furthermore, landslide occurrence increases for slopes steeper than 350 and in shale and limestone formations. Within the major drainage basins of Sinduhupalchok, the maximum surface area affected by landsliding is approximately one percent, and approximately 75% of the documented landslides occur within 120 km of the M7.8 epicenter.
The compiled landslide inventory was calibrated and validated based on detailed observations made during two post-earthquake field investigations. The first investigation was performed from May 16 – 22, 2017, directly after the main earthquake shock and prior to the monsoon season. The follow up investigation was performed from October 16 – 22, 2017, directly after the monsoons. provides a detailed account of the performance of steep mountain terrain subjected to strong ground shaking, as well as valuable insights for assessing future seismic slope performance in Sinduhupalchok and neighboring districts of Nepal.
| Originalsprache | englisch |
|---|---|
| Publikationsstatus | Veröffentlicht - 2018 |
| Veranstaltung | 2018 XIII IAEG Congress : Engineering Geology for a Sustainable World - San Francisco, USA / Vereinigte Staaten Dauer: 15 Sept. 2018 → 23 Sept. 2018 |
Konferenz
| Konferenz | 2018 XIII IAEG Congress |
|---|---|
| Land/Gebiet | USA / Vereinigte Staaten |
| Ort | San Francisco |
| Zeitraum | 15/09/18 → 23/09/18 |