A user guide for the GeoSure Extra : Debris Flow Susceptibility Model for Great Britain (Version 6.0)

This report is the published product of a study by the British Geological Survey (BGS) to produce a national scale Debris Flow Susceptibility Map for Great Britain. It builds on research BGS has conducted over the past decade investigating debris flows and extends the work conducted by Harrison et al., (2006) as part of the Transport Scotland Scottish Road Network Landslides Study (Winter et al., 2005, Winter et al., 2009). The Debris Flow Susceptibility Model provides information on the potential of the ground, at a given location, to form a debris flow. It is based on a combination of digital geological, hydrogeological and topographic data. The methodology develops an additional dimension to the BGS GeoSure Landslides surface layer (Dashwood et al., 2014) and is designed for users interested specifically in debris flow susceptibility. This document outlines the background to why the dataset was created, its potential uses and gives a brief description of the GIS raster file. Technical information regarding the GIS and how the data were created is described and advice is provided on using the dataset.