Landslide susceptibility mapping: a practitioner's view

Reichenbach et al. (Earth Sci Rev 180:60-91, 2018) provide an extremely valuable review of statistically-based landslide susceptibility modelling and mapping techniques. In their analysis, they describe an excessive interest in statistical experimentation, seemingly at the expense of focusing on developing reliable and useable outputs. Landslide susceptibility mapping has flourished in research circles, but has yet to become widely embraced by land use planners and those responsible for the site selection and route selection of engineering infrastructure. If landslide susceptibility mapping is to become recognised as a credible tool by planning and engineering practitioners, it requires robust and universally-applied guidelines, a focus on geological and geomorphological observation, and demonstrable reliability and usability. Short case histories are provided to illustrate some of the issues concerned, how they have been overcome in an applied sense, and some of the problems that still remain to be resolved. Recommendations are provided for a step-by-step approach to landslide susceptibility mapping, that emphasise the need to: (1) become fully-familiar with the terrain in the area of interest and the controls on slope stability; (2) derive a credible dataset for spatial analysis, combining desk study and field-derived data sources; (3) test and trial the output mapping; and (4) liaise with the intended map end-user over issues concerning scale, reliability, uncertainty and application constraints.