{"id":4000,"date":"2011-12-05T22:55:22","date_gmt":"2011-12-05T22:55:22","guid":{"rendered":"http:\/\/blogs.agu.org\/landslideblog\/?p=4000"},"modified":"2011-12-05T22:55:23","modified_gmt":"2011-12-05T22:55:23","slug":"agu-1-landslide-characterisation-and-forecasting","status":"publish","type":"post","link":"https:\/\/blogs.agu.org\/landslideblog\/2011\/12\/05\/agu-1-landslide-characterisation-and-forecasting\/","title":{"rendered":"AGU 1: Landslide characterisation and forecasting"},"content":{"rendered":"

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My intention in terms of blogging at AGU is to post on those talks and sessions that I find interesting.\u00a0 This is not going to be comprehensive, and if I miss your talk it does not mean that I didn’t enjoy it or value it.\u00a0 It is just that there is so much…<\/p>\n

So first up this morning was an oral session in landslide characterisation and forecasting, which was wide-ranging and very engaging.\u00a0 My thoughts went to Susan Cannon of the USGS<\/strong>, who had the misfortune to talk first (8 am on Monday morning), covering debris flow initiation in the aftermath of wildfires in Southern California.\u00a0 They have classified the landslides according to the intensity of the events (volume and number of debris flows), and then compared this with the intensity \/ duration relationship for the triggering rainfall event.\u00a0 They achieved impressive relationship between the two, providing an opportunity to develop a warning system that is potentially useful for decision-makers.\u00a0 In many ways the most interesting aspect of this is the ways in which it can be actually used by the emergency services, but unfortunately there was less detail than would be ideal.\u00a0 Sometimes the very short time-slots at AGU (15 mins) are a real constraint.<\/p>\n

Next up was a talk by Silvia Peruccacci and her colleagues from CNR-IRPI<\/strong> in Italy, who talked about the development of rainfall intensity – duration thresholds for landslide initiation.\u00a0 This is a well-trodden path, but pleasingly there was a really new element to this work.\u00a0 This was the application of a statistical approach to determine the threshold, a significant step forward.\u00a0 This then allowed objective comparison of thresholds between different areas, between different lithologies in the same area, and between different seasons.\u00a0 I think there are two immediate upshots from this.\u00a0 First, it was interesting to note that in their field area in Italy the winter and the summer thresholds were different – quite a surprising result, and one that I am not sure that I understand.\u00a0 Is this the effect of vegetation I wonder?\u00a0 Second, the overall thresholds proved to be somewhat lower than other studies in the same area had shown.\u00a0 This is great work.<\/p>\n

Third into bat was Doug Stead and his colleagues from Canada<\/strong>, who talked about mechanisms of rock slope failure as shown by numerical modelling.\u00a0 Most pleasing about this talk was an emphasis on the importance of the (under-estimated) process of progressive failure, and a recognition of the role of time dependent processes.\u00a0 They are working to analyse that amazing Cornwall cliff collapse video (which gives me an opportunity to show it again):<\/p>\n