8 October 2010
Most readers will be aware that I collate statistics for fatal landslides occurring worldwide. I have now processed the statistics for September, and the results are as follows:
This compares with the following average number for 2002-2009:
Number of landslide events that caused one or more fatalities worldwide: 37.4
Number of people killed by landslides:770
So, September has finally reversed the trend seen for most of the previous months of this year to date in which landslide occurrence has been much higher than average. This graph shows the cumulative total number of recorded landslides that have caused one or more fatalities. It includes the cumulative total number of recorded fatality-inducing landslides for 2003 (which had the lowest total of any year on the database), 2009 (the previous record year), 2010 to the end of September, and the average for 2003-2009. Even though September was not exceptional, the cumulative total for the year remains exceptional:
With the monsoon now weakening and the northern hemisphere tropical cyclone season drawing to a close, the peak period of landslides worldwide is now coming to an end. However, typically the occurrence of landslides in Central and South America, and in SE Asia, starts to increase in late October.
One other point to note about September 2010. This month has seen two landslides in which there were initially very high estimates that were subsequently (rather quietly) reduced. The highest profile was the 27th September landslide at Santa Maria Tlahuitoltepec in Oaxaca in Mexico, which was initially estimated to have killed hundreds, and possibly thousands. The final death toll was eleven people. The second case is the remarkable landslide at Giraldo in Colombia, that was caught on video:
In this case the initial estimates were that 30 people were killed. This has now been reduced to 10 people.