Handling high predictor dimensionality in slope-unit-based landslide susceptibility models through LASSO-penalized Generalized Linear Model

Castro-Camilo, D. , Lombardo, L., Mai, P. M., Dou, J. and Huser, R. (2017) Handling high predictor dimensionality in slope-unit-based landslide susceptibility models through LASSO-penalized Generalized Linear Model. Environmental Modelling and Software, 97, pp. 145-156. (doi:10.1016/j.envsoft.2017.08.003)

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Abstract

Grid-based landslide susceptibility models at regional scales are computationally demanding when using a fine grid resolution. Conversely, Slope-Unit (SU) based susceptibility models allows to investigate the same areas offering two main advantages: 1) a smaller computational burden and 2) a more geomorphologically-oriented interpretation. In this contribution, we generate SU-based landslide susceptibility for the Sado Island in Japan. This island is characterized by deep-seated landslides which we assume can only limitedly be explained by the first two statistical moments (mean and variance) of a set of predictors within each slope unit. As a consequence, in a nested experiment, we first analyse the distributions of a set of continuous predictors within each slope unit computing the standard deviation and quantiles from 0.05 to 0.95 with a step of 0.05. These are then used as predictors for landslide susceptibility. In addition, we combine shape indices for polygon features and the normalized extent of each class belonging to the outcropping lithology in a given SU. This procedure significantly enlarges the size of the predictor hyperspace, thus producing a high level of slope-unit characterization. In a second step, we adopt a LASSO-penalized Generalized Linear Model to shrink back the predictor set to a sensible and interpretable number, carrying only the most significant covariates in the models. As a result, we are able to document the geomorphic features (e.g., 95% quantile of Elevation and 5% quantile of Plan Curvature) that primarily control the SU-based susceptibility within the test area while producing high predictive performances. The implementation of the statistical analyses are included in a parallelized R script (LUDARA) which is here made available for the community to replicate analogous experiments.

Item Type:Articles
Keywords:High predictor dimensionality, slope unit-based landslide susceptibility, LASSO penalized variable selection, R scripting, open-sourcing.
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Castro Camilo, Dr Daniela
Authors: Castro-Camilo, D., Lombardo, L., Mai, P. M., Dou, J., and Huser, R.
College/School:College of Science and Engineering > School of Mathematics and Statistics > Statistics
Journal Name:Environmental Modelling and Software
Publisher:Elsevier
ISSN:1364-8152
ISSN (Online):1873-6726
Published Online:30 August 2017

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