Skip to main content

Research Repository

Advanced Search

Modelling post-earthquake cascading hazards: Changing patterns of landslide runout following the 2015 Gorkha earthquake, Nepal

Kincey, ME; Rosser, NJ; Densmore, AL; Robinson, TR; Shrestha, R; Pujara, DS; Horton, P; Swirad, SM; Oven, KJ; Arrell, K

Modelling post-earthquake cascading hazards: Changing patterns of landslide runout following the 2015 Gorkha earthquake, Nepal Thumbnail


Authors

Profile Image

Mark Kincey m.e.kincey@durham.ac.uk
PGR Student Doctor of Philosophy

TR Robinson

R Shrestha

DS Pujara

P Horton

SM Swirad

KJ Oven

K Arrell



Abstract

Coseismic landslides represent the first stage of a broader cascading sequence of geohazards associated with high-magnitude continental earthquakes, with the subsequent remobilization of coseismic landslide debris posing a long-term post-seismic legacy in mountain regions. Here, we quantify the controls on the hazard posed by landslide remobilization and debris runout, and compare the overlap between areas at risk of runout and the pattern of post-seismic landslides and debris flows that actually occurred. Focusing on the 2015 Mw 7.8 Gorkha earthquake in Nepal, we show that the extent of the area that could be affected by debris runout remained elevated above coseismic levels 4.5 years after the event. While 150 km2 (0.6% of the study area) was directly impacted by landslides in the earthquake, an additional 614 km2 (2.5%) was left at risk from debris runout, increasing to 777 km2 (3.2%) after the 2019 monsoon. We evaluate how this area evolved by comparing modelled predictions of runout from coseismic landslides to multi-temporal post-seismic landslide inventories, and find that 14% (85 km2) of the total modelled potential runout area experienced landslide activity within 4.5 years after the earthquake. This value increases to 32% when modelled runout probability is thresholded, equivalent to 10 km2 of realized runout from a remaining modelled area of 32 km2. Although the proportion of the modelled runout area from coseismic landslides that remains a hazard has decreased through time, the overall runout susceptibility for the study area remains high. This indicates that runout potential is changing both spatially and temporally as a result of changes to the landslide distribution after the earthquake. These findings are particularly important for understanding evolving patterns of cascading hazards following large earthquakes, which is crucial for guiding decision-making associated with post-seismic recovery and reconstruction.

Citation

Kincey, M., Rosser, N., Densmore, A., Robinson, T., Shrestha, R., Pujara, D., …Arrell, K. (2023). Modelling post-earthquake cascading hazards: Changing patterns of landslide runout following the 2015 Gorkha earthquake, Nepal. Earth Surface Processes and Landforms, 48(3), 537-554. https://doi.org/10.1002/esp.5501

Journal Article Type Article
Acceptance Date Oct 7, 2022
Online Publication Date Nov 14, 2022
Publication Date Mar 15, 2023
Deposit Date Oct 7, 2022
Publicly Available Date May 23, 2023
Journal Earth Surface Processes and Landforms
Print ISSN 0197-9337
Electronic ISSN 1096-9837
Publisher British Society for Geomorphology
Peer Reviewed Peer Reviewed
Volume 48
Issue 3
Pages 537-554
DOI https://doi.org/10.1002/esp.5501

Files

Published Journal Article (5 Mb)
PDF

Publisher Licence URL
http://creativecommons.org/licenses/by/4.0/

Copyright Statement
© 2022 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd.

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.





You might also like



Downloadable Citations