23 November 2022

High resolution Planet Labs images of the Kusiong landslides in the Philippines

Posted by Dave Petley

High resolution Planet Labs images of the Kusiong landslides in the Philippines

Earlier this month I posted Planet Labs PlanetScope imagery of the Kusiong landslides in the Philippines.  Rob Simmon has now acquired on my behalf a high resolution SkySat image of the area that shows the full extent of the devastation that the landslide have caused:-

Planet Labs SkySat image of the Kusiong landslides in the Philippines.

Planet Labs SkySat image of the Kusiong landslides in the Philippines. Image copyright Planet Labs, used with permission, captured on 12 November 2022.

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This is just a part of the area affected by the landslides – see my original post for the full extent.  In this area multiple shallow landslides can be seen, clustered on the slopes in the upper part of the catchments:-

Planet Labs SkySat image of a cluster of the Kusiong landslides in the Philippines.

Planet Labs SkySat image of a cluster of the Kusiong landslides in the Philippines.  Image copyright Planet Labs, used with permission, captured on 12 November 2022.

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In this image alone there are over 50 landslides.  Note that they are all shallow, that they originate high on the slope (which is likely to indicate failure driven by saturation caused by very intense rainfall) and they connect to the river system.  Thus, as I noted previously, this is a tragic, textbook example of shallow failures transitioning to channelised debris flows.

Elsewhere in the image the impact of the debris flows on communities is clearly visible:-

Planet Labs SkySat image of a destructive debris flow, part of the Kusiong landslides in the Philippines.

Planet Labs SkySat image of a destructive debris flow, part of the Kusiong landslides in the Philippines. Image copyright Planet Labs, used with permission, captured on 12 November 2022.

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Note the inundation of the houses and the damage to the land at this site.  It is notable that at the time of acquisition the road remained covered in debris.

The most serious damage, and many of the fatalities, occurred in a settlement on the upper slopes at 7.142, 124.088.  This is the location of the photograph that I originally posted.  The magnitude of the destruction at this location is laid bare in the imagery:-

Planet Labs SkySat image of the destruction caused by the Kusiong landslides in the Philippines

Planet Labs SkySat image of the destruction caused by the Kusiong landslides in the Philippines. Image copyright Planet Labs, used with permission, captured on 12 November 2022.

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Many houses were destroyed in this community.  Interestingly, Google Earth imagery from September 2019 shows no community at this site, and from December 2020 show just a small number of houses.

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Reference and acknowledgements

The images are from the wonderful people at Planet Labs.  Thanks in particular to Rob Simmon,

Planet Team (2022). Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://www.planet.com/