Journal Article

Debris-flow susceptibility of upland catchments

Liébault, F, Piegay, H, Erosion torrentielle neige et avalanches (UR ETGR (ETNA)) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Centre National de la Recherche Scientifique (CNRS), Bertrand, M

2013

Overview

Over the last three decades, many regional studies in mountain ranges under temperate climate revealed that it is possible to discriminate debris-flow and fluvial fans from morphometric indicators measured at the scale of the catchment and the fan itself. The most commonly used indicators are the Melton index (R), a normalized index of the gravitational energy of the catchment, and the fan slope (S). A wide range of thresholds have been proposed for discriminating purpose, but these are generally based on a small population of catchments and may be highly influenced by ambiguous fans included in the data set. A database of 620 upland catchments from several mountain ranges under temperate climate was compiled from the literature to propose robust discriminant morphometric thresholds for debris-flow versus fluvial responses. Linear discriminant analysis (LDA) and logistic regression (LR) were performed using the whole data set, and a leave-one-out cross-validation was used to evaluate performances of the models. Sensitivity and specificity scores obtained for LDA and LR were 0.96 and 0.73, and 0.95 and 0.75, respectively. It is also shown that the channel slope above which debris-flow is observed decreases with the gravitational energy of the catchment. Limitations of the morphometric discrimination are discussed.

• Publisher: Springer Verlag,CCSD,Springer Netherlands,Springer,Springer Nature B.V
• Subject: Catchments / Civil Engineering / Debris flow / Detritus / Discriminant analysis / Earth and Environmental Science / Earth Sciences / Earth, ocean, space / Engineering and environment geology. Geothermics / Environmental Management / Environmental Sciences / Exact sciences and technology / Geophysics/Geodesy / Geotechnical Engineering & Applied Earth Sciences / Hydrogeology / Hydrology / Hydrology. Hydrogeology / Landslides & mudslides / Natural Hazards / Natural hazards: prediction, damages, etc / Original Paper / Regression analysis / Risk assessment