31 May 2012
Updated: A movie of the annual cycle of rainfall-induced landslides in Asia
Posted by Dave Petley
Updated – I have now created and uploaded a better version
In preparation for my opening keynote lecture at the International Symposium on Landslides in Banff next week, I have been working on producing some animated movies of maps of landslides worldwide. This has been based on the work that I have been undertaking for almost a decade now collating data on landslides that kill people. I thought that it would be fun to produce a set of short films to show the annual cycle of landslides. I am still working on this (and it has been a steep learning curve), but I have out my first prototype online on Youtube.
The for the movie below is based upon this map of Asian landslides – here each white dot represents a landslide that killed at least one person in the period between 1st January 2004 and 31st December 2010. Note that only landslides that killed someone are included, and no indication is given of the number of deaths in each event:
Note the background image here is the SRTM global elevation model (i.e. colors indicate elevation). Of course, whilst useful, this map does not really indicate the seasonality of the landslides. So, I have classified each landslide by week of the year (i.e. week 1 is 1st to 7th January, week 2 is 8th to 14th January, etc. Note that week 52 has 8 days!). I have then animated this dataset to produce a movie. It is at the moment somewhat less than perfect – I am working on improving it – but it is an interesting start:
What it shows is the way that the number of landslides dramatically increases in the summer months as the monsoon winds up, especially in South Asia and China Note also the way landslides in Indonesia and the Philippines really get going late in the year.
I am currently working on a global version of this, which is actually a little better. I will put this online in the next few days, and as usual I will put the presentation on Authorstream early next week.
I am sure that some readers will be in Banff – I shall really look forward to meeting up with you. Let’s have a beer (or two)!