8 April 2018
Fatal landslides in 2017
I have now been able to complete the database of fatal landslides or 2017 (an increasingly challenging task given the commitments of my day job). This is the 15th full year in which I have compiled this dataset, which I formally wrote up in the journal Geology a few years ago. I have written about this work many times before, and Melanie and I have a paper with the most recent analysis of the data under open peer review (please do take a look and leave a review if you have time).
In total in 2017 I recorded 453 landslides worldwide that caused loss of life, excluding landslides caused by earthquakes. In total these caused 4,164 deaths. The graph below shows the annual total number of fatal landslides since 2003:-
So, 2017 was the third worst year in this 15 year dataset, and 2016 and 2017 have reversed the slight downward trend seen in the period from 2010 to 2015. The data continue to show a statistically-significant upward trend over the full period of the study, but no significant trend since about 2009. I remain unclear as to whether this is because I became better at capturing the data, or whether there is a genuine increasing trend. The dataset needs to be much longer to be able to deduce a meaningful trend that exclude the possible effects of improvement in methodology. It is likely though that the number of events is not decreasing, despite our increasing knowledge of landslides and their mitigation. This is quite depressing.
The graph below shows the number of fatal landslides recorded each month in 2017, again excluding the coseismic events:-
As usual the very strong seasonality in the data is clear, with the highest totals falling in the Northern Hemisphere summer – i.e. June to September. This is the effect of the Asian monsoon. It is interesting to note that more events occurred in August than in July – it is generally the opposite way around.
The graph below shows the cumulative total number of fatal landslides and landslide-induced fatalities through the year:-
Note the large steps in the number of people killed. This reflect the contribution of a small number of larger events. The largest step was caused by the terrible Regent landslide in Sierra Leone on 14th August (1309 deaths). Other significant events include the Mocoa landslide in Colombia on 1st April (406 deaths), the somewhat enigmatic Ituri landslide in the Democratic Republic of Congo on 16th August (240 deaths); the Koshe garbage landslide in Ethiopia on 11th March (125 deaths); and the Xinmo landslide in Sichuan, China on 14th June (83 deaths). Rainstorms that caused multiple fatal landslide events occurred in Sri Lanka in May and Bangladesh in June.
A number of earthquakes probably caused landslide fatalities, but I have not been able to extract these from the available datasets as yet.