Assessing the hazard of low frequency, high magnitude landslide events; the role of the engineering geologist

Posted on 22nd September 2016

Lecture by Steve Parry, Consulting Engineering Geologist, in association with the Geological Society (North West Regional Group), the North Wales Geology Association, and the Department of Geography and International Development at the University of Chester.

During a severe rainstorm on 7 June 2008, over 2,400 landslides were recorded on Lantau Island, the largest island in Hong Kong. Numerous road links were severed and many landslides impinged on existing residential developments. This was one of the most notable storms to have occurred in Hong Kong in several decades, with a 4-hour rolling rainfall equated to a return period of 500-1000 years. A number of the landslides developed into major debris flows, with significant secondary entrainment and long run out distances. Such hazards were underrepresented in the existing data sets at that time. The presentation will outline the approach to landslide assessments in Hong Kong, discuss the hazard from debris flow with reference to the 2008 storm, illustrate the uncertainty associated with assessing debris flow hazard and examine how this uncertainty can be reduced.

Whilst there are limited historical records of debris flows in the UK, they have been documented in North Wales, the Lake District and Scotland, with the impact on the A83 Rest and be Thankful being most notable. There is also evidence that the frequency of such events is increasing and the lessons learnt in Hong Kong are useful for the evaluation low frequency, high magnitude debris flows in the UK.

Thursday 10th November 2016


Registration and refreshments at 6.30pm

Seminar begins at 7.00pm

Everyone welcome