28 August 2018

Mapping global landslides

Posted by Dave Petley

Mapping global landslides

As I noted last week, as part of our work on deaths caused by global landslides, my colleague Melanie Froude has been establishing an online tool that allows mapping of that landslides on the database.  This tool is now online using an ESRI ARCGIS mapping tool.  It’s probably fair to say that at this stage it is a little experimental, and I warn in particular against trying to interpret too much from any individual record.  The most difficult element in compiling a database like this is in identifying the precise location of each landslide.  In the vast majority of cases the information that we have does not pin the location to a particular slope.  Thus, we map the landslide as sitting within an area, the size of which reflects the precision of the report, and from this we distill a single point to display online.  In some cases, where the uncertainty is large, we cannot map the landslide.

But the tool does provide a global and regional view of the distribution of losses from landslides.  The remarkable unevenness of the distribution of global landslides is clear:-

Global landslides

The distribution of global landslides. Data from Froude and Petley (2018).

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We have tried to provide the ability to look in more detail at the data.  So, for example, there are layers that display the distribution of landslides caused by mining, both legal and illegal (unregulated):-

Global landslides

The distribution of global landslides caused by legal and illegal mining. Data from Froude and Petley (2018).

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The data show that mining-induced fatal landslides are rare in richer countries, but are common in less developed nations, especially in tropical and subtropical environments.  These landslides are mostly avoidable.

The data should be useful at a higher resolution too.  I have frequently written on this blog about the high frequency of landslides in Nepal – examination of the data in the mapping tool explains why this is such a concern:-

Global landslides

The distribution of fatal landslides in Nepal. Data from Froude and Petley (2018).

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Reference

Froude, M. J. and Petley, D. N. 2018. Global fatal landslide occurrence from 2004 to 2016. Natural Hazards and Earth System Sciences, 18, 2161-2181, https://doi.org/10.5194/nhess-18-2161-2018.