18 October 2022

Las Tejerías: landslides in the upstream catchment

Posted by Dave Petley

Las Tejerías: landslides in the upstream catchment

Cloud is continuing to render it difficult to get a full understanding of the causes of the 8-9 October 2022 Las Tejerías landslide disaster in Venezuela, obstructing the view from satellites.  However, loyal reader Fab has found a tweet with some helicopter video taken in the catchment.  The Tweet should be visible below:

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The video was posted by Gregoria Díaz, a journalist in Venezuela.  The footage is very revealing.  Right at the start it incudes images of two sets of disrupted rockslides in steep catchments:

Landslides in the catchment of the Rio Las Tejerías.

Landslides in the catchment of the Rio Las Tejerías. Still from a video tweeted by Gregoria Díaz (@churuguara).

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Other parts of the video show shallow failures with long debris trails on steep forested slopes:-

Shallow landslides with long debris trails in the catchment of the Rio Las Tejerías.

Shallow landslides with long debris trails in the catchment of the Rio Las Tejerías. Still from a video tweeted by Gregoria Díaz (@churuguara).

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In the second set of images the landslides appear to be comparatively small initial failures, shallow in nature, which have then entrained soil and debris downslope.  In most cases there appears to be good connectivity with the main channel.

Thus, an initial diagnosis is that the Las Tejerías landslide disaster was caused by extreme rainfall in the catchment that triggered multiple landslides, which evolved into channelised debris flows that travelled down the main channel to impact the town.

In terms of losses, the confirmed number of fatalities is now 54, with a further eight people remaining missing.

Heavy rainfall continues to cause losses in other parts of Venezuela.  In El Costano, a suburb of Maracay, the capital of Aragua state, a mudslide killed three people on 17 October 2022.  Once again there is dramatic footage on Twitter showing the landslides in full flow:

https://twitter.com/EarthquakeChil1/status/1582094549249245184

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Interestingly, the President of Venezuela Nicolas Maduro has been clear as to the causes of these landslides, as reported by France 24 / AFP:

Maduro later traveled to El Castano, where he said “all this is climate change.”

“This year the rainfall has been very difficult for the whole country.”

Maduro said that in 2022, he has seen the worst natural disasters in his nine and a half years in office.