Flash floods are one of the most destructive natural hazards in mountainous regions due to their its rapid onset, high velocities, and short warning time. Erratic rainfall, cloudbursts, landslide, and climate-induced hydrological variability are the prime factors to trigger flash floods in the Himalayan region. The Melamchi River Basin in central Nepal has witness recurrent flash flood events, most notably the catastrophic 2021 flood. An Integrated hazard assessment and resilience planning are needed to mitigate effect of such events in future. The present study is GIS-based assessment of flash flood hazard and community resilience using a multi-criteria decision analysis (MCDA) approach. Key contributing factors such as slope, elevation, drainage density, flow accumulation, rainfall intensity, land use/land cover, and valley confinement were integrated using the Analytical Hierarchy Process (AHP). These factors are used to generate a flash flood susceptibility map in Melamchi River Basin. The resulting susceptibility map were overlaid with settlement and infrastructure data to evaluate exposure and risk. Very high flash flood susceptibility zones are concentrated along narrow, steep river valleys and downstream confluences, where communities and vital infrastructure are vulnerable. The resilience assessment highlights the effectiveness of community-based early warning systems and local preparedness initiatives. The study also reveals a gaps in structural mitigation and land-use regulation. It emphasises the importance of basin-scale flash flood zoning, nature-based solutions, and strengthened community resilience frameworks for disaster risk reduction in Himalayan region.

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1. Adhikari, J. N., Bhattarai, B. P., Rokaya, M. B., & Thapa, B. (2022a). Land use/land cover changes in the central part of the Chitwan Annapurna Landscape, Nepal. PeerJ, 10. https://doi.org/10.7717/peerj.13435
2. Adhikari, J. , Bhattarai, B. P., Rokaya, M. B., & Thapa, T. B. (2022b). Land use/land cover changes in the central part of the Chitwan Annapurna Landscape, Nepal. PeerJ, 10. https://doi.org/10.7717/peerj.13435
3. Adhikari, , Lamichhane, P., Karki, J., Mishra, S., Rana, D., Mandal, A., Tamang, S., Paudel,H. K., Regmi, S., Bohora, A., Parajuli, S., Pangeni, A., Sthapit, E., Sharma, S., Aryal, D., Chhetri, T. B., Pandey, V. P., & Pokharel, B. (2025). Analyzing Extreme Precipitation during the Prolonged Summer Monsoon of 2022 in Nepal: Insights from Hourly Observational Data. Journal of Institute of Science and Technology, 30(1), 179–188. https://doi.org/10.3126/jist.v30i1.70014
4. Adhikari, T. R., Baniya, B., Tang, Q., Talchabhadel, R., Gouli, M. R., Budhathoki, B. R., & Awasthi, P. (2023). Evaluation of post extreme floods in high mountain region: A casestudy of the Melamchi flood 2021 at the Koshi River Basin in Nepal. Natural Hazards Research, 3(3), 437–446. https://doi.org/10.1016/j.nhres.2023.07.001
5. Ali, M. (2023). CAUSES AND IMPACTS OF FLASH FLOODS ON LIVES AND LIVELIHOODS IN HIRSHABELLE STATE OF SOMALIA. Ecofeminism and Climate Change, 4(1), 51–55. https://doi.org/10.26480/efcc.01.2023.51.55
6. Al-Kindi, K. M., & Alabri, Z. (2024). Investigating the Role of the Key Conditioning Factors in Flood Susceptibility Mapping Through Machine Learning Earth Systems and Environment, 8(1), 63–81. https://doi.org/10.1007/s41748-023-00369-7
7. Amadio, M., Behrer, P., Bosch, L., Kaila, H., Krishnan, N., & Molinario, G. (2023). World Bank-Nepal, Poverty and Equity Global Practice Climate risks, exposure, vulnerability and resilience in Nepal 1.
8. Assessing Flood Vulnerability Zones and Their Driving Factors to Guide Community-Based Resilience Planning Across Ngororero District, (2024). Journal of Agriculture, 8(1). https://doi.org/10.53819/81018102t2386
9. Ba, H., Nam, T. V., & Hung, L. (2023). Knowledge of Flash Floods and Related Problems.In: Flash Floods in Vietnam.Springer.
10. Babu Shreevastav, B., Raj Tiwari, K., Asheshwar Mandal, R., & Author, C. (2019). Flood Scenario and its Risk Management, Policy, Practices in Nepal. Annals of Ecology and Environmental Science, 3(2), 1–14.
11. Beven, K. J., & Kirkby, M. J. (1979). A physically based, variable contributing area model of basin hydrology. Hydrological Sciences Bulletin, 24(1), 43–69. https://doi.org/10.1080/02626667909491834
12. Bhardwaj, A., Wasson, R. J., Ziegler, A. D., Chow, W. T. L., & Sundriyal, Y. P. (2019). Characteristics of rain-induced landslides in the Indian Himalaya: A case study of the Mandakini Catchment during the 2013 flood. Geomorphology, 330, 100–115. https://doi.org/10.1016/j.geomorph.2019.01.010
13. Bikash, S., Steiner, J. F., Shrestha, A. B., Maharjan, A., Nepal, S., Singh Shrestha, M., Bajracharya, , Rasul, G., Shrestha, M., Jackson, M., & Gupta, N. (2021). The Melamchi flood disaster Cascading hazard and the need for multihazard risk management.
14. Chaudhary, S., Kumar, , Pramanik, M., & Pal, I. (2025). Influence of Altitude and Climate on the Distribution of Vegetation, Ecosystem Services and Human Population in Garhwal Himalayan Region. Journal of Geographical Studies, 9(1), 11–33. https://doi.org/10.21523/gcj5
15. Devkota, R. P. D. (2013). Flood Vulnerability through the Eyes of Vulnerable People in Mid- Western Terai of Nepal. Journal of Earth Science & Climatic Change, 04(01). https://doi.org/10.4172/2157-7617.100013
16. Dimri, P., Chevuturi, A., Niyogi, D., Thayyen, R. J., Ray, K., Tripathi, S. N., Pandey, A. K., & Mohanty, U. C. (2017). Cloudbursts in Indian Himalayas: A review. In Earth-Science Reviews(Vol.    168,     pp.       1–23).      Elsevier B.V. https://doi.org/10.1016/j.earscirev.2017.03.006
17. Gurung, N., & Narayan Gurung, P. (n.d.). Natural hazards vs. anthropogenic activities in the Nepal Himalayas : negative and positive trends Université de Paris Natural hazards versus anthropogenic activities in the Nepal Himalaya: Positive and negative trends. Retrieved https://theses.hal.science/tel-03888197v1
18. Kayastha, R. B., & Maskey, S. (2024). Glacial lake outburst flood (GLOF) modeling of Tsho Rolpa glacial lake, Nepal. Proceedings of IAHS, 387, 59–63. https://doi.org/10.5194/piahs-387-59-2024
19. Kuksina, L., & Golosov, (2020). Flash floods: Formation, study and distribution. E3S Web of Conferences, 163. https://doi.org/10.1051/e3sconf/202016302005
20. Kumar, S., Parida, B. R., & Ahammed, K. K. B. (2025). Flood risk assessment of the Kosi River Basin in North Bihar using Synthetic Aperture Radar (SAR) data and AHP Natural                         Hazards            Research,          5(3),                     618–632. https://doi.org/10.1016/j.nhres.2025.02.002
21. Kushwaha, A. P., Solanki, H., Vegad, U., Mahto, S. S., & Mishra, V. (2024a). Land and Atmospheric Drivers of the 2023 Flood in India. Earth and Space Science, 11(10). https://doi.org/10.1029/2024EA003750
22. Kushwaha, A. P., Solanki, H., Vegad, U., Mahto, S. S., & Mishra, V. (2024b). Land and Atmospheric Drivers of the 2023 Flood in India. Earth and Space Science, 11(10). https://doi.org/10.1029/2024EA003750
23. Naghibi, S. A., Pourghasemi, H. R., & Dixon, B. (2016). GIS-based groundwater potential mapping using boosted regression tree, classification and regression tree, and random forest machine learning models in Iran. Environmental Monitoring and Assessment, 188(1), 1–27. https://doi.org/10.1007/s10661-015-5049-6
24. Oliva, A., & Olcina, J. (2024). Floods and Structural Anthropogenic Barriers (Roads and Waterworks) Affecting the Natural Flow of Waters: Hydraulic Modelling and Proposals for the Final Section of the River Segura (Spain). GeoHazards, 5(4), 1220–1246. https://doi.org/10.3390/geohazards5040058
25. Opiyo, S. B., Pienaar, L., Piketh, S. J., Burger, R. P., Chikoore, H., & Havenga, H. (2025). Assessment of vegetation density trends in response to long-term climate change impacts in Western South Africa (1962–2022) using SPEI and NDVI time series. Discover Forests, 1(1). https://doi.org/10.1007/s44415-025-00030-3
26. Pangali Sharma, T. P., Zhang, J., Koju, U. A., Zhang, S., Bai, Y., & Suwal, M. K. (2019). Review of flood disaster studies in Nepal: A remote sensing In International Journal of            Disaster           Risk     Reduction(Vol.    34,       pp.       18–27).            Elsevier           Ltd. https://doi.org/10.1016/j.ijdrr.2018.11.022
27. Rasmussen, K. L., & Houze, R. A. (2012). A flash-flooding storm at the steep edge of high terrain. Bulletin of the American Meteorological Society, 93(11), 1713–1724. https://doi.org/10.1175/BAMS-D-11-00236.1
28. Saaty Thomas, & Vargas, L. (1980). Models, Methods, Concepts & Applications of the Analytic Hierarchy Process. In International Series in Operations Research & Management Science. http://www.springer.com/series/6161
29. Sharma, , Poonia, M., Rai, A., Biniwale, R. B., Tügel, F., Holzbecher, E., & Hinkelmann, R. (2024). Flood Susceptibility Mapping Using GIS-Based Frequency Ratio and Shannon’s Entropy Index Bivariate Statistical Models: A Case Study of Chandrapur District, India. ISPRS International Journal                    of                     Geo-Information,                           13(8). https://doi.org/10.3390/ijgi13080297
30. Tehrany, S., Pradhan, B., & Jebur, M. N. (2014). Flood susceptibility mapping using a novel ensemble weights-of-evidence and support vector machine models in GIS. Journal of Hydrology, 512, 332–343. https://doi.org/10.1016/j.jhydrol.2014.03.008
31. Thapa, , Shrestha, A., Lamichhane, S., Adhikari, R., & Gautam, D. (2020). Catchment-scale flood hazard mapping and flood vulnerability analysis of residential buildings: The case of Khando River in eastern Nepal. Journal of Hydrology: Regional Studies, 30. https://doi.org/10.1016/j.ejrh.2020.100704
32. Upreti, N. (1999). An overview of the stratigraphy and tectonics of the Nepal Himalaya.
33. Upreti, B. N., Sharma, T., & Merh, S. S. (1980). STRUCTURAL GEOLOGY OF KUSMA- SIRKANG SECTION OF THE KALI GANDAKI VALLEY AND ITS BEARING ON THE TECTONIC FRAMEWORK OF NEPAL HIMALAYA(Vol. 62).
34. Wang, , Yang, C., Sun, Y., Liu, H., Liu, Y., & Xing, H. (2025). A new method for evaluating the coordinated relationship between vegetation greenness and urbanization. Scientific Reports, 15(1). https://doi.org/10.1038/s41598-025-89701-x
35. Yiran, A. B., Oteng Ababio, M., Allotey, A. N. M., Kofie, R. Y., & Møller-Jensen, L. (2024). Spatial Analysis of Exposure of Roads to Flooding and Its Implications for Mobility in Urban/Peri-Urban Accra. ISPRS International Journal of Geo-Information, 13(4). https://doi.org/10.3390/ijgi13040111
36. Youssef, M., Pradhan, B., & Hassan, A. M. (2011). Flash flood risk estimation along the St. Katherine road, southern Sinai, Egypt using GIS based morphometry and satellite imagery. Environmental Earth Sciences, 62(3), 611–623. https://doi.org/10.1007/s12665- 010-0551-1
37. Zhang, , Li, L., Zhao, X., Chen, F., Wei, J., Feng, Z., Hou, T., Chen, Y., Yue, W., Shang, H., Wang, S., & Hu, M. (2024). Changes in Vegetation NDVI and Its Response to Climate

Flash floods are one of the most destructive natural hazards in mountainous regions due to their its rapid onset, high velocities, and short warning time. Erratic rainfall, cloudbursts, landslide, and climate-induced hydrological variability are the prime factors to trigger flash floods in the Himalayan region. The Melamchi River Basin in central Nepal has witness recurrent flash flood events, most notably the catastrophic 2021 flood. An Integrated hazard assessment and resilience planning are needed to mitigate effect of such events in future. The present study is GIS-based assessment of flash flood hazard and community resilience using a multi-criteria decision analysis (MCDA) approach. Key contributing factors such as slope, elevation, drainage density, flow accumulation, rainfall intensity, land use/land cover, and valley confinement were integrated using the Analytical Hierarchy Process (AHP). These factors are used to generate a flash flood susceptibility map in Melamchi River Basin. The resulting susceptibility map were overlaid with settlement and infrastructure data to evaluate exposure and risk. Very high flash flood susceptibility zones are concentrated along narrow, steep river valleys and downstream confluences, where communities and vital infrastructure are vulnerable. The resilience assessment highlights the effectiveness of community-based early warning systems and local preparedness initiatives. The study also reveals a gaps in structural mitigation and land-use regulation. It emphasises the importance of basin-scale flash flood zoning, nature-based solutions, and strengthened community resilience frameworks for disaster risk reduction in Himalayan region.

🔒 This is a subscription article

Full text is available to subscribers and institutional members. Please choose an option below to access it.

1. Adhikari, J. N., Bhattarai, B. P., Rokaya, M. B., & Thapa, B. (2022a). Land use/land cover changes in the central part of the Chitwan Annapurna Landscape, Nepal. PeerJ, 10. https://doi.org/10.7717/peerj.13435
2. Adhikari, J. , Bhattarai, B. P., Rokaya, M. B., & Thapa, T. B. (2022b). Land use/land cover changes in the central part of the Chitwan Annapurna Landscape, Nepal. PeerJ, 10. https://doi.org/10.7717/peerj.13435
3. Adhikari, , Lamichhane, P., Karki, J., Mishra, S., Rana, D., Mandal, A., Tamang, S., Paudel,H. K., Regmi, S., Bohora, A., Parajuli, S., Pangeni, A., Sthapit, E., Sharma, S., Aryal, D., Chhetri, T. B., Pandey, V. P., & Pokharel, B. (2025). Analyzing Extreme Precipitation during the Prolonged Summer Monsoon of 2022 in Nepal: Insights from Hourly Observational Data. Journal of Institute of Science and Technology, 30(1), 179–188. https://doi.org/10.3126/jist.v30i1.70014
4. Adhikari, T. R., Baniya, B., Tang, Q., Talchabhadel, R., Gouli, M. R., Budhathoki, B. R., & Awasthi, P. (2023). Evaluation of post extreme floods in high mountain region: A casestudy of the Melamchi flood 2021 at the Koshi River Basin in Nepal. Natural Hazards Research, 3(3), 437–446. https://doi.org/10.1016/j.nhres.2023.07.001
5. Ali, M. (2023). CAUSES AND IMPACTS OF FLASH FLOODS ON LIVES AND LIVELIHOODS IN HIRSHABELLE STATE OF SOMALIA. Ecofeminism and Climate Change, 4(1), 51–55. https://doi.org/10.26480/efcc.01.2023.51.55
6. Al-Kindi, K. M., & Alabri, Z. (2024). Investigating the Role of the Key Conditioning Factors in Flood Susceptibility Mapping Through Machine Learning Earth Systems and Environment, 8(1), 63–81. https://doi.org/10.1007/s41748-023-00369-7
7. Amadio, M., Behrer, P., Bosch, L., Kaila, H., Krishnan, N., & Molinario, G. (2023). World Bank-Nepal, Poverty and Equity Global Practice Climate risks, exposure, vulnerability and resilience in Nepal 1.
8. Assessing Flood Vulnerability Zones and Their Driving Factors to Guide Community-Based Resilience Planning Across Ngororero District, (2024). Journal of Agriculture, 8(1). https://doi.org/10.53819/81018102t2386
9. Ba, H., Nam, T. V., & Hung, L. (2023). Knowledge of Flash Floods and Related Problems.In: Flash Floods in Vietnam.Springer.
10. Babu Shreevastav, B., Raj Tiwari, K., Asheshwar Mandal, R., & Author, C. (2019). Flood Scenario and its Risk Management, Policy, Practices in Nepal. Annals of Ecology and Environmental Science, 3(2), 1–14.
11. Beven, K. J., & Kirkby, M. J. (1979). A physically based, variable contributing area model of basin hydrology. Hydrological Sciences Bulletin, 24(1), 43–69. https://doi.org/10.1080/02626667909491834
12. Bhardwaj, A., Wasson, R. J., Ziegler, A. D., Chow, W. T. L., & Sundriyal, Y. P. (2019). Characteristics of rain-induced landslides in the Indian Himalaya: A case study of the Mandakini Catchment during the 2013 flood. Geomorphology, 330, 100–115. https://doi.org/10.1016/j.geomorph.2019.01.010
13. Bikash, S., Steiner, J. F., Shrestha, A. B., Maharjan, A., Nepal, S., Singh Shrestha, M., Bajracharya, , Rasul, G., Shrestha, M., Jackson, M., & Gupta, N. (2021). The Melamchi flood disaster Cascading hazard and the need for multihazard risk management.
14. Chaudhary, S., Kumar, , Pramanik, M., & Pal, I. (2025). Influence of Altitude and Climate on the Distribution of Vegetation, Ecosystem Services and Human Population in Garhwal Himalayan Region. Journal of Geographical Studies, 9(1), 11–33. https://doi.org/10.21523/gcj5
15. Devkota, R. P. D. (2013). Flood Vulnerability through the Eyes of Vulnerable People in Mid- Western Terai of Nepal. Journal of Earth Science & Climatic Change, 04(01). https://doi.org/10.4172/2157-7617.100013
16. Dimri, P., Chevuturi, A., Niyogi, D., Thayyen, R. J., Ray, K., Tripathi, S. N., Pandey, A. K., & Mohanty, U. C. (2017). Cloudbursts in Indian Himalayas: A review. In Earth-Science Reviews(Vol.    168,     pp.       1–23).      Elsevier B.V. https://doi.org/10.1016/j.earscirev.2017.03.006
17. Gurung, N., & Narayan Gurung, P. (n.d.). Natural hazards vs. anthropogenic activities in the Nepal Himalayas : negative and positive trends Université de Paris Natural hazards versus anthropogenic activities in the Nepal Himalaya: Positive and negative trends. Retrieved https://theses.hal.science/tel-03888197v1
18. Kayastha, R. B., & Maskey, S. (2024). Glacial lake outburst flood (GLOF) modeling of Tsho Rolpa glacial lake, Nepal. Proceedings of IAHS, 387, 59–63. https://doi.org/10.5194/piahs-387-59-2024
19. Kuksina, L., & Golosov, (2020). Flash floods: Formation, study and distribution. E3S Web of Conferences, 163. https://doi.org/10.1051/e3sconf/202016302005
20. Kumar, S., Parida, B. R., & Ahammed, K. K. B. (2025). Flood risk assessment of the Kosi River Basin in North Bihar using Synthetic Aperture Radar (SAR) data and AHP Natural                         Hazards            Research,          5(3),                     618–632. https://doi.org/10.1016/j.nhres.2025.02.002
21. Kushwaha, A. P., Solanki, H., Vegad, U., Mahto, S. S., & Mishra, V. (2024a). Land and Atmospheric Drivers of the 2023 Flood in India. Earth and Space Science, 11(10). https://doi.org/10.1029/2024EA003750
22. Kushwaha, A. P., Solanki, H., Vegad, U., Mahto, S. S., & Mishra, V. (2024b). Land and Atmospheric Drivers of the 2023 Flood in India. Earth and Space Science, 11(10). https://doi.org/10.1029/2024EA003750
23. Naghibi, S. A., Pourghasemi, H. R., & Dixon, B. (2016). GIS-based groundwater potential mapping using boosted regression tree, classification and regression tree, and random forest machine learning models in Iran. Environmental Monitoring and Assessment, 188(1), 1–27. https://doi.org/10.1007/s10661-015-5049-6
24. Oliva, A., & Olcina, J. (2024). Floods and Structural Anthropogenic Barriers (Roads and Waterworks) Affecting the Natural Flow of Waters: Hydraulic Modelling and Proposals for the Final Section of the River Segura (Spain). GeoHazards, 5(4), 1220–1246. https://doi.org/10.3390/geohazards5040058
25. Opiyo, S. B., Pienaar, L., Piketh, S. J., Burger, R. P., Chikoore, H., & Havenga, H. (2025). Assessment of vegetation density trends in response to long-term climate change impacts in Western South Africa (1962–2022) using SPEI and NDVI time series. Discover Forests, 1(1). https://doi.org/10.1007/s44415-025-00030-3
26. Pangali Sharma, T. P., Zhang, J., Koju, U. A., Zhang, S., Bai, Y., & Suwal, M. K. (2019). Review of flood disaster studies in Nepal: A remote sensing In International Journal of            Disaster           Risk     Reduction(Vol.    34,       pp.       18–27).            Elsevier           Ltd. https://doi.org/10.1016/j.ijdrr.2018.11.022
27. Rasmussen, K. L., & Houze, R. A. (2012). A flash-flooding storm at the steep edge of high terrain. Bulletin of the American Meteorological Society, 93(11), 1713–1724. https://doi.org/10.1175/BAMS-D-11-00236.1
28. Saaty Thomas, & Vargas, L. (1980). Models, Methods, Concepts & Applications of the Analytic Hierarchy Process. In International Series in Operations Research & Management Science. http://www.springer.com/series/6161
29. Sharma, , Poonia, M., Rai, A., Biniwale, R. B., Tügel, F., Holzbecher, E., & Hinkelmann, R. (2024). Flood Susceptibility Mapping Using GIS-Based Frequency Ratio and Shannon’s Entropy Index Bivariate Statistical Models: A Case Study of Chandrapur District, India. ISPRS International Journal                    of                     Geo-Information,                           13(8). https://doi.org/10.3390/ijgi13080297
30. Tehrany, S., Pradhan, B., & Jebur, M. N. (2014). Flood susceptibility mapping using a novel ensemble weights-of-evidence and support vector machine models in GIS. Journal of Hydrology, 512, 332–343. https://doi.org/10.1016/j.jhydrol.2014.03.008
31. Thapa, , Shrestha, A., Lamichhane, S., Adhikari, R., & Gautam, D. (2020). Catchment-scale flood hazard mapping and flood vulnerability analysis of residential buildings: The case of Khando River in eastern Nepal. Journal of Hydrology: Regional Studies, 30. https://doi.org/10.1016/j.ejrh.2020.100704
32. Upreti, N. (1999). An overview of the stratigraphy and tectonics of the Nepal Himalaya.
33. Upreti, B. N., Sharma, T., & Merh, S. S. (1980). STRUCTURAL GEOLOGY OF KUSMA- SIRKANG SECTION OF THE KALI GANDAKI VALLEY AND ITS BEARING ON THE TECTONIC FRAMEWORK OF NEPAL HIMALAYA(Vol. 62).
34. Wang, , Yang, C., Sun, Y., Liu, H., Liu, Y., & Xing, H. (2025). A new method for evaluating the coordinated relationship between vegetation greenness and urbanization. Scientific Reports, 15(1). https://doi.org/10.1038/s41598-025-89701-x
35. Yiran, A. B., Oteng Ababio, M., Allotey, A. N. M., Kofie, R. Y., & Møller-Jensen, L. (2024). Spatial Analysis of Exposure of Roads to Flooding and Its Implications for Mobility in Urban/Peri-Urban Accra. ISPRS International Journal of Geo-Information, 13(4). https://doi.org/10.3390/ijgi13040111
36. Youssef, M., Pradhan, B., & Hassan, A. M. (2011). Flash flood risk estimation along the St. Katherine road, southern Sinai, Egypt using GIS based morphometry and satellite imagery. Environmental Earth Sciences, 62(3), 611–623. https://doi.org/10.1007/s12665- 010-0551-1
37. Zhang, , Li, L., Zhao, X., Chen, F., Wei, J., Feng, Z., Hou, T., Chen, Y., Yue, W., Shang, H., Wang, S., & Hu, M. (2024). Changes in Vegetation NDVI and Its Response to Climate