TY  - JOUR
A1  - Goetz, Jason
A1  - Kohrs, Robin
A1  - Parra Hormazábal, Eric
A1  - Bustos Morales, Manuel
A1  - Araneda Riquelme, María Belén
A1  - Henríquez Ruiz, Cristian
A1  - Brenning, Alexander
T1  - Optimizing and validating the Gravitational Process Path model for regional debris-flow runout modelling
JF  - Natural hazards and earth system sciences : NHESS / European Geophysical Society
N2  - Knowing the source and runout of debris flows can help in planning strategies aimed at mitigating these hazards. Our research in this paper focuses on developing a novel approach for optimizing runout models for regional susceptibility modelling, with a case study in the upper Maipo River basin in the Andes of Santiago, Chile. We propose a two-stage optimization approach for automatically selecting parameters for estimating runout path and distance. This approach optimizes the random-walk and Perla et al.'s (PCM) two-parameter friction model components of the open-source Gravitational Process Path (GPP) modelling framework. To validate model performance, we assess the spatial transferability of the optimized runout model using spatial crossvalidation, including exploring the model's sensitivity to sample size. We also present diagnostic tools for visualizing uncertainties in parameter selection and model performance. Although there was considerable variation in optimal parameters for individual events, we found our runout modelling approach performed well at regional prediction of potential runout areas. We also found that although a relatively small sample size was sufficient to achieve generally good runout modelling performance, larger samples sizes (i.e. >= 80) had higher model performance and lower uncertainties for estimating runout distances at unknown locations. We anticipate that this automated approach using the open-source R software and the System for Automated Geoscientific Analyses geographic information system (SAGA-GIS) will make process-based debris-flow models more readily accessible and thus enable researchers and spatial planners to improve regional-scale hazard assessments.
Y1  - 2021
U6  - https://doi.org/10.5194/nhess-21-2543-2021
SN  - 1561-8633
SN  - 1684-9981
VL  - 21
IS  - 8
SP  - 2543
EP  - 2562
PB  - European Geophysical Society
CY  - Katlenburg-Lindau
ER  -