Geological contribution on landslide distribution in Siwaliks of parts of central and eastern Nepal
DOI:
https://doi.org/10.3126/njes.v14i1.91639Keywords:
Geology, Siwaliks, landslide distribution, NepalAbstract
The Siwalik is the youngest among all the geological units within the Nepal Himalaya, and it is inherently weak and fragile. Conservation of the Siwalik region in Nepal has become a national challenge, and the government is currently committed to bring breakthrough in controlling landslides. Therefore, a study was conducted in the Siwaliks of central and eastern Nepal to understand the spatial distribution of landslides in different geological formations. A geological formation distribution map is prepared by collecting lithological and structural geological data from the field, and the spatial distribution of the landslide is delineated from satellite images as well as field visits. It is found that the Siwaliks in the study area are divisible into Lower, Middle, and Upper Siwaliks. In terms of landslide distribution, the Middle Siwaliks is more hazardous in terms of landslide occurrence than the other two. In an average, 60% of the total landslides in the study area fall within the Middle Siwaliks, 22% fall within Upper Siwaliks, and 13% landslides have occurred in Lower Siwaliks. It is also found that highly weathered rock beds in Lower and Upper Siwaliks favor shallow failures, whereas the easily erodible mudstone layers interbedded with comparatively less erodible sandstone layers in the Middle Siwaliks make it unstable and more prone to rock slides and rock falls. It indicates the control of geology in landslide occurrences and their types. This study will provide insights into the possible geological controls for landslides throughout the Siwaliks and support for preparing a geohazard management strategy in the study area.
Downloads
References
Auden, J.B. (1935). Traverses in the Himalaya, Rec. Geological Survey of India, 69, 123169.
Bhandari, B.P., & Dhakal, S. (2021). A multidisciplinary approach of landslide characterization: A case of the Siwalik zone of Nepal Himalaya. Journal of Asian Earth Sciences, 10(5), 100061. https://doi.org/10.1016/j.jaesx.2021.100061
Bhandari, B.P., & Dhakal, S. (2020). Spatio-temporal dynamics of landslides in the sedimentary terrain: a case of Siwalik zone of Babai watershed, Nepal. SN Applied Science, 2, 854. https://doi.org/10.1007/s42452-020-2628-0
Bhandari, B.P., & Dhakal, S. (2018). Lithological control on landslide in the Babai Khola Watershed, Siwaliks Zone of Nepal. American Journal of Earth Sciences, 5, 54-64. http://www.openscienceonline.com/journal/ajes
Dahal, R.K., & Hasegawa, S. (2008). Representative rainfall thresholds for landslides in the Nepal Himalaya. Geomorphology, 100(3–4), 429–443.
Dewey, J.F., Cande, S., & Pitman, W.C. (1989). Tectonic evolution of the India/Eurassia collision zone. Eclogae Geologicae Helvetiae, 82, 717-734.
Dewey, J.F., & Bird, J.M. (1970). Mountain belts and the new global tectonics. Journal of Geophysical Research, 75, 2625-2647.
Dhakal, S., & Tamang, N.B. (2025). Landslide susceptibility assessment in the Marin Khola watershed of the sub Himalaya, Central Nepal. Journal of Institute of Science and Technology, 30(1), 89-99.
Dhakal, S. (2015). Evolution of Geomorphologic Hazards in Hindu Kush Himalaya, In Shaw, R., & Nibanupudi, H.K. (Eds.), Mountain hazards and disaster risk reduction (pp. 53-72).
Dhakal, S. (2014). Geological Divisions and Associated Hazards in Nepal, In Khadka, U.R. (Eds.), Contemporary environmental issues and methods in Nepal (pp. 100-109). Central Department of Environmental Science, Tribhuvan University Nepal.
DMG. (2023). Generalized geological map of Nepal, scale 1:1,000,000. Department of Mines and Geology, Government of Nepal.
Gansser, A. (1964). Geology of the Himalayas. Interscience, London.
GoN. (2024). River basin atlas of Nepal. Water and Energy Commission Secretariat (WECS), Government of Nepal, Kathmandu.
Le Fort, P. (1975). Himalayas; the collided range: Present knowledge of the Continental Arc. American Journal of Science, 275(A), 1-44.
Neupane, M., & Dhakal, S. (2017). Climatic variability and land use change in Kamala Watershed, Sindhuli District, Nepal. Climate, 5(1), 11.
Powel, C.McA., & Conagan, P.J. (1973). Plate tectonics and the Himalayas. Earth and Planetary Science Letters, 20(1), 1-12.
Rai, S.M., Upreti, B.N., Dhakal, S., Bhattarai, T.N., Adhikari, B.R., Bajracharya, S.R., & Yoshida, M. (2017). Climate change impact on glacier retreat and local community in the Langtang Valley, Central Nepal. Journal of Development Innovations, 1(1), 45–59.
Sah, R.B., Huyghe, P., Mugnier, J.L., Ojha, T., & Guillot, S. (2003). Sedimentary architecture and tectonic evolution of the Neogene Siwalik Group in eastern Nepal. Journal of Asian Earth Sciences, 22(3), 307–322.
Searle, M.P., Windley, B.P., Coward, M.P., Cooper, D.J.W., Rex, A.J., Red, D., Li, T.D., Xiao, X.C., Jan, M.Q., Thakur, V.C., & Surendar, K. (1987). The closing of Tethys and the tectonics of Himalaya, Geological Society of America Bulletin, 98(6), 678-701.
Sharma, S., Talchabhadel, R., Nepal, S., Ghimire, G.R., Rakhal, B., Panthi, J., Adhikari, B.R., Pradhanang, S.M., Maskey, S., & Kumar, S. (2023). Increasing risk of cascading hazards in the central Himalayas. Natural Hazards, 119(2), 1117-1126. https://doi.org/10.1007/s11069-022-05462-0Au
Tokuoka, T., Takayasu, K., Yoshida, M., & Hisatomi, K. (1986). The Churia (Siwalik) Group of the Arung Khola area, West Central Nepal. The Memoirs of the Faculty of Science and Engineering, Shimane University, 20, 135–210.
TU-CDES. (2016). Landslide inventory characterization and engineering design for mitigation works of Chure Area in ten districts. Central Department of Environmental Science, Tribhuvan University and Government of Nepal, President Chure-Tarai Madhesh Conservation Development Board, Kathmandu.
Ulak, P.D., & Nakayama, K. (2001). Neogene fluvial systems in the Siwalik Group along the Tinau Khola section, west-central Nepal Himalaya. Journal of Nepal Geological Society, 25, 111–122.
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2026 Central Department of Environmental Science, Tribhuvan University
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
This license enables reusers to distribute, remix, adapt, and build upon the material in any medium or format for noncommercial purposes only, and only so long as attribution is given to the creator.
