3 May 2022
The Pilar landslide in the Philippines
One of the largest landslides triggered by Tropical Storm Megi last month occurred at Pilar, a little to the southeast of the town of Abuyong in Leyte. This location, which is also known as Dang’s Beach Resort, suffered from one of the three very large landslides during the storm. It is located at 10.717, 125.040. The latest NDRRMC situation report lists 53 known fatalities at this site.
Planet has succeeded in collecting a high resolution satellite image of the landslide at Pilar:-
By way of comparison, this is a Google Earth image of the same area, collected in June 2016:-
A particularly interesting aspect of this landslide is that it clearly generated destructive displacement waves when it reached the sea. The damage to the main part of the seaside resort appears to be consistent with damage caused by these waves:-
There is a paper in the Annals of Tropical Research (Cabelin and Jadina 2019) that analyses of the soils in landslide areas in the Cadac-an Watershed, which includes the site of this landslide. It notes that:
“…it was concluded that the soils are susceptible to landslide occurrence.
“It is highly recommended to conduct constant assessment and monitoring of landslide occurrences in the area. Moreover, it is encouraged to plant more trees, prohibit tree cutting, delineate danger zone , establish more rain gauge stations and provide early warning systems to somehow prepare for the consequences brought about by landslides.”
It is hard to disagree.
References and acknowledgement
Planet Team (2022). Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://www.planet.com/
Cabelin, J.P. and Jadina, B.C. 2019. Physical characteristics of soils in landslide areas of Cadac-an Watershed in Leyte, Philippines. Annals of Tropical Research 41 (2) 11-129.
Thanks to Robert Simmon and Anne Pelligrino for their support in acquiring the image.