Earthquake Induced Landslide Susceptibility Mapping
Area of Interest - Kadavu, Fiji
Request Description: After the earthquake on the 8th November, 2019 there were reports of landslides in Kadavu. NDMO reached out to UNOSAT to support them delineating future landslide susceptible areas for their mitigation planning purposes.
Requesting Organisation: National Disaster Management Officer, Ministry of Infrastructure, Transport, Disaster Management and Meteorological Services
Thematic Area: Disaster Risk Reduction from Natural Hazards
Support Details: A simplified landslide susceptibility map was prepared using the geological classes and slop steepness. For details of the methodology please refer to Annex I.
*Click on the box to view the map
The geological map was reclassified into three categories based on expert judgement.
World Elevation Data 30-meter from The Japan Aerospace Exploration Agency (JAXA) was used to create the slope map.
Area of Interrest - Kadavu, Fiji.
Meaning of colors represented in the map.
Landslide Susceptibility Web Map
Annex I: Methodology
For this specific study simplified Wilson and Keefer (1985) method was adopted largely due to lack of primary data. The geology classification is based on two parameters c' is the effective cohesion, ø' is the effective internal angle of internal friction.
Full publication here (Page 4-29 to 4-35)
Earthquake Induced Landslide Susceptibility of Geologic Groups by Wilson and Keefer (1985)
Disclaimers
- This is a very simplistic method does not consider other factors like landcover, Fault-line location etc.
- The DEM used was received from global source, the accuracy is unknown for that exact area.
- It is unclear whether the soil was at wet or dry condition during the earthquake.
