Presenting the Results of Algorithm-Based Rainfall Thresholds for Landslide Initiation Across Different Regions of Nepal
DOI:
https://doi.org/10.64862/Keywords:
Landslides, Landslide early warning system, Rainfall thresholds, Disaster Risk ReductionAbstract
Landslides are a major hazard in Nepal, driven by steep terrain, fragile geology, and intense monsoon rainfall. This study establishes region-specific rainfall thresholds for landslide initiation using satellite-based GPM IMERG data and ground-based DHM rain gauge observations, applying the CTRL-T algorithm for reproducibility. Hourly and daily rainfall-landslide datasets were analysed for Bagmati and Karnali provinces, while thresholds for highly affected districts in Koshi, Gandaki, Lumbini, and Sudurpashchim were derived from gauge data. Results reveal significant spatial variability, with lower thresholds in Bagmati and Karnali and higher thresholds in Jajarkot and Taplejung. Rain gauge-based thresholds were slightly higher than satellite-derived ones, while satellite products showed lower uncertainty but tended to underestimate extreme rainfall. Findings highlight the need for consistent data sources and localized thresholds to improve Landslide Early Warning Systems (LEWS) in Nepal.
References
Bhattarai, S., Dahal, R. K., and Pradhan, A. M. S. (2024). Comparative analysis of rainfall thresholds for landslide initiation using terrestrial rain gauges and satellite data in Nepal: Challenges and opportunities. Asian Journal of Engineering Geology, 1(Special Issue), 7–8. https://ajeg.nseg.org.np/index.php/ajeg/article/view/11
Dahal, R. K., and Hasegawa, S. (2008). Representative rainfall thresholds for landslides in the Nepal Himalaya. Geomorphology, 100, 429–443. https://doi.org/10.1016/j.geomorph.2008.01.014
Guzzetti, F., Peruccacci, S., Rossi, M., and Stark, C. P. (2008). The rainfall intensity–duration control of shallow landslides and debris flows: An update. Landslides, 5, 3–17. https://doi.org/10.1007/s10346-007-0112-1
Malakar, Y. (2014). Community-based rainfall observation for landslide monitoring in western Nepal. In K. Sassa, P. Canuti, and Y. Yin (Eds.), Landslide science for a safer geoenvironment, Vol. 2: Methods of landslide studies (pp. 757–763). Springer. https://doi.org/10.1007/978-3-319-05050-8_117
Melillo, M., Brunetti, M. T., Peruccacci, S., Gariano, S. L., and Guzzetti, F. (2018). A tool for the automatic calculation of rainfall thresholds for landslide occurrence. Environmental Modelling and Software, 105, 230–243. https://doi.org/10.1016/j.envsoft.2018.03.024
Pradhan, A. M. S. (2020). Preparation of landslide catalogue (1970–2019) of Nepal. https://doi.org/10.13140/RG.2.2.27290.11202
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