25 October 2022
The Las Tejerías landslide disaster: Planet Labs imagery of the source of the flows
Posted by Dave Petley
The Las Tejerías landslide disaster: Planet Labs imagery of the source of the flows
The cloud has now cleared sufficiently that Planet Labs has been able to capture an image of the source area of the 8-9 October 2022 Las Tejerías landslide disaster in Venezuela. The image below was captured by one of the PlanetScope instruments on 22 October 2022:-
.
The main channel, which flows towards the south to the site of the town, cuts across the image from the west to the south. To the north of the channel there is evidence of many shallow landslides, most of which feed into tributaries of the main channel. In the main drainage line the evidence of high flows can be seen in the form of sediment and/or bedrock exposed or deposited on the channel floor.
For reference, the image below shows the same location on 23 September 2022, before the disaster:-
.
In the juxtapose below I have tried to compare the two images:-
.
The juxtapose images highlight clearly the role of the multiple shallow landslides that have become channelised mudflows / debris flows to cause the destruction in the town. These types of landslides are characteristic of extreme rainfall events.
Meanwhile, heavy rainfall continues to cause extensive damage in Venezuela, with another period of rainfall occurring yesterday. This video shows flooding in Montaña Alta:-
https://twitter.com/noticiasjdg/status/1584657238719098882
.
Reference and acknowledgements
The images are from the wonderful people at Planet Labs.
Planet Team (2022). Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://www.planet.com/
I remember in 1999 when extensive mass wasting of this nature occurred along the Caribbean coast of Venezuela. Numerous towns and small cities built on broad alluvial fans at the coast were devastated. The photos taken in and around Caraballeda are dramatic. This is a good overview:
https://pubs.usgs.gov/fs/fs-0103-01/fs-0103-01.pdf