Dear CEE community, 

Please join us this Thursday, October 31 at 3:30 in More Hall room 220 for the environment and water program seminar. This week Earth and Space Sciences PhD candidate Paul Morgen will talk about Landslide Dams. Please see Paul’s abstract and bio below.   

You can find the fall program here: https://depts.washington.edu/watersem/

Landslide Dams, what are they and where will they happen next?:  A probabilistic approach to regional landslide dam susceptibility analysis

Paul Morgan

Earth and Space Sciences, UW

Landslides can form river dams that require rapid response to mitigate catastrophic outburst floods. In this talk I will discuss landslide dams, why we should care about them and present a workflow to map landslide dam formation susceptibility at a regional scale. I define a probabilistic dam formation domain (DFD) function that combines river valley width and landslide volume to efficiently determine the likelihood of a landslide damming a river or ‘damability’. We combine damability values with existing landslide susceptibility to find landslide dam susceptibility.  We verify and apply our approach to the Oregon Coast Range, USA and find high susceptibility in steep river headwaters, and in more resistant lithologies. We also estimate volumes of the potential dammed lakes and find that most rivers with high dam susceptibility are less likely to impound large lakes, because they have low drainage areas. However, widespread susceptibility, and the critical potential impacts from exceptionally large landslides suggest this hazard should be considered in the Pacific Northwest. The DFD function workflow is flexible to the addition of new data and can be applied more broadly to assess future landslide dam hazards. 

Short bio:  Continue reading →