August fatal landslide data

The end of the month marks the point at which I post the accumulated totals for fatal landslides, based upon the global fatal landslide database that I maintain.  The raw figures for August are stark.  The total number of fatal landslides recorded in the month was 71, resulting in 2,740 fatalities.  This total is of course dominated by the Zhouqu landslide in China, which is reported to have resulted in 1,765 deaths.  (Click on read more to access the remainder of this post).


These totals continue the exceptional trend of landslide occurrence in 2010.  The average number of recorded fatality-inducing landslides in August in the period 2002-2009 is 46.7, resulting in an average of 348.3 deaths.

This graph illustrates the magnitude of the anomaly for 2010 to date.  This shows 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 August, and the average for 2003-2009.  There is no doubt that 2010 is exceptional:

It is interesting that these totals have been recorded in a year that to date has had exceptionally low levels of tropical cyclone activity - indeed Northern Hemisphere tropical cyclone energy release remains at the lowest level for 30 years.   When they occur, landfalling NW Pacific tropical cyclones (typhoons) have a major impact upon landslide occurrence.  It is notable in particular that the Philippines and the Caribbean islands (especially Haiti) have been spared substantial tropical cyclone events to date this year.  Given that there are strong signs that tropical cyclone activity is currently increasing in both the N. Atlantic and the Pacific, the next month will be very interesting.

Of course, the root cause of the exceptional occurrence of recorded landslides in August has been the intensity and volume of rainfall associated with the summer monsoon, primarily in China and Pakistan, and to a lesser extent Nepal.  The monsoon should start to weaken during September, but more landslides are likely in the interim given the near-saturated state of the ground.

August 2009 fatal landslide map

Here is the fatal landslide map for August 2009. As usual each yellow dot represents a single landslide that killed one or more people:

Click on the map for a better (downloadable) view in a new window.

The statistics are as follows:
Number of recorded fatal landslides: 53
Number of fatalities: 782

In terms of fatalities this places August well above the 2002-2008 average (347 fatalities). Of course this is dominated by Typhoon Morakot in Taiwan, and in particular the landslide at Hsiaolin. However, the map shows clearly the impact of the SW monsoon along the southern edge of the Himalayas and also the impact of typhoons in E. Asia. Elsewhere there is the normal smattering of landslides here and there. The lack of slides in S. America is perhaps surprising. The paucity of hurricanes in the Caribbean means that this area is not figuring at the moment. I wonder if we will see a large, late season event.

August 2008 fatal landslide map

Better late than never (just a tad busy at the moment...), here is the fatal landslide map for August 2008. First the statistics:
Number of recorded fatal landslides: 61
Number of recorded fatalities: 537

As such August was substantially above the average for the last five years (212 fatalities). This is interesting as regular readers will know that until the end of July most months have been substantially below the five year average. July was particularly low. Therefore, this sudden increase in activity in August is slightly surprising and will be worthy of detailed analysis in due course.

So, first the map for August 2008. As ever, you will need to click on the map to get a decent view of it:

A few things to note:

1. The very strong cluster along the Himalayan Arc is now very evident. Nepal in particular is suffering an intense period of landslides.
2. There is also a clear cluster in the Caribbean as the Hurricane season starts to take its toll.
3. China is also experiencing a few events, but with no clear pattern.

The map of the year to date is shown below. Again, click on the map for a decent view. The normal clusters are now well developed. Compare this map with that from 2007 (see here). The similarity between the two patterns is now very clear.

I welcome any comments, corrections and clarifications.