The Landslide Blog is written by Dave Petley, who is widely recognized as a world leader in the study and management of landslides.
Following my annual leave in Chile, I have finally been able to catch up with the fatal landslide data for August 2024. This follows my post for the end of July, which indicated fatal landslides occurring at a record high rate. As usual, this data does not include events triggered by earthquakes.
In August 2024, I recorded 65 fatal landslides around the word, down from the record high of 100 in July (this is an update on the figure I recorded previously). In total, those 65 landslides claimed 414 lives.
This is the monthly total fatal landslide graph to the end of August:-
As expected, the rate at which fatal landslides have been occurring through August is down from the previous month, reflecting the weakening of the Asian monsoons, especially in South Asia.
As I have noted previously, the best way to present fatal landslide data through the annual cycle is to use pentads (five day blocks). The graph below shows the cumulative number of fatal landslides using pentads, with two typical previous years also included:-
This graph illustrates the continued exceptional nature of 2024, with the total number of landslides being far higher than in previous years. In general, the number of landslides dramatically reduces through August but in 2024 this reduction has been far less marked.
Finally, the graph below shows the monthly cumulative number of landslides, with all previous years shown in grey:-
The most likely explanation for this acutely anomalous behaviour in 2024 is most likely to be the exceptionally high global atmospheric and sea surface temperatures, which has generated very high rainfall intensities and totals in many locations. As temperatures are starting to reduce, we will probably see the anomalously high total number of landslides also reduce (the August total that I have recorded was exceeded in both 2017 and 2018). However, the SW monsoon has not yet totally withdrawn across South Asia, and the tropical cyclone season remains active in the West Pacific and Atlantic basins, so we are likely to see a comparatively lively September.
In all of the years I have been collecting this data, I have never recorded 500 fatal landslides in a year. This total will be exceeded in September 2024.