Kelantan has been facing several cases of catastrophic flooding, causing significant damage to this area. Heavy monsoon rainfall is believed to trigger those floods. This study aims to identify and classify the flood occurrence using the Kelantan River catchment’s flood hazard index (FHI) based on the analytical hierarchy process (AHP). This study developed the FHI using the AHP based on spatial analysis in the geographic information system (GIS) environment. Six physical parameters were selected: annual rainfall, slope, river density, land use and land cover (LULC); elevation; and soil permeability. According to the AHP model, the annual rainfall was the first ranked parameter in terms of importance weight score. Moreover, Tanah Merah and Jeli were the high-risk areas for floods. The present study suggests that the GIS-based AHP method can be highly effective for mapping flood hazards and benefit flood management decision-making.

• Alias, N. E., Salim, N. A., Taib, S. M., Yusof, M. B. M., Saari, R., Ramli, M. W. A., Othman, I. K., Annammala, K. V., Yusof, H. M., Ismail, N., Yuzir, A., & Blenkinsop, S. (2020). Community responses on effective flood dissemination warnings - A case study of the December 2014 Kelantan Flood, Malaysia. Journal of Flood Risk Management, 13(S1), Article e12552. https://doi.org/10.1111/jfr3.12552

• Bronstert, A., Niehoff, D., & Bürger, G. (2002). Effects of climate and land-use change on storm runoff generation: Present knowledge and modelling capabilities. Hydrological Processes, 16(2), 509-529. https://doi.org/10.1002/hyp.326

• Burby, R. J., Deyle, R. E., Godschalk, D. R., & Olshansky, R. B. (2000). Creating hazard resilient communities through land-use planning. Natural Hazards Review, 1(2), 99-106. https://doi.org/10.1061/(ASCE)1527-6988(2000)1:2(99)

• Chen, H., Ito, Y., Sawamukai, M., & Tokunaga, T. (2015). Flood hazard assessment in the Kujukuri plain of Chiba prefecture, Japan, based on GIS and multicriteria decision analysis. Natural Hazards, 78(1), 105-120. https://doi.org/10.1007/s11069-015-1699-5

• de Brito, M. M., & Evers, M. (2016). Multi-criteria decision-making for flood risk management: A survey of the current state of the art. Natural Hazards and Earth System Sciences, 16(4), 1019-1033. https://doi.org/10.5194/nhess-16-1019-2016

• DID. (2014). Laporan Banjir Negeri Kelantan. Department of Irrigation and Drainage Malaysia.

• Detrembleur, S., Stilmant, F., Dewals, B., Erpicum, S., Archambeau, P., & Pirotton, M. (2015). Impacts of climate change on future flood damage on the river Meuse, with a distributed uncertainty analysis. Natural Hazards, 77, 1533-1549. https://doi.org/10.1007/s11069-015-1661-6

• Du, S., Shi, P., Van Rompaey, A., & Wen, J. (2015). Quantifying the impact of impervious surface location on flood peak discharge in urban areas. Natural Hazards, 76, 1457-1471. https://doi.org/10.1007/s11069-014-1463-2

• FAO-UNESCO. (1990). FAO-Unesco soil map of the world. World Soil Resources Report 60ISRIC. https://www.isric.org/sites/default/files/ISRIC_TechPap20.pdf

• Green, C. H., Parker, D. J., & Turnstall, S. M. (2000). Assessment of flood control and management options. World Commission on Dams. https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.467.4860&rep=rep1&type=pdf

• Jaafar, A. S., Sidek, L. M., Basri, H., Zahari, N. M., Jajarmizadeh, M., Noor, H. M., Osman, S., Mohammad, A. H., & Azad, W. H. (2016). An overview: flood catastrophe of Kelantan watershed in 2014. In W. Tahir, S. H. A. Bakar, M. A. Wahid, S. R. M. Nasir & W. K. Lee (Eds.), ISFRAM 2015 (pp. 17-29). Springer. https://doi.org/10.1007/978-981-10-0500-8_2

• Kaoje U. I., Rahman, M. Z. A., Idris, N. H., Razak, K. A., Rani, W. N. M. W. M., Tam, T. H., & Salleh, M. R. M. (2021). Physical flood vulnerability assessment using geospatial indicator-based approach and participatory analytical hierarchy process: A case study in Kota Bharu, Malaysia. Water, 13(13), Article 1786. https://doi.org/10.3390/w13131786

• Kazakis, N., Kougias, I., & Patsialis, T. (2015). Assessment of flood hazard areas at a regional scale using an index-based approach and analytical hierarchy process: Application in Rhodope-Evros region, Greece. Science of the Total Environment, 538, 555-563. https://doi.org/10.1016/j.scitotenv.2015.08.055

• Mudashiru, R. B., Sabtu, N., Abdullah, R., Saleh, A., & Abustan, I. (2022). A comparison of three multi-criteria decision-making models in mapping flood hazard areas of Northeast Penang, Malaysia. Natural Hazards, 112, 1903-1939. https://doi.org/10.1007/s11069-022-05250-w

• Murali, M. R., Ankita, M., Amrita, S., & Vethamony, P. (2013). Coastal vulnerability assessment of Puducherry coast, India, using the analytical hierarchical process. Natural Hazards and Earth System Sciences, 13(12), 3291-3311. https://doi.org/10.5194/nhess-13-3291-2013

• Nashwan, M. S., Ismail, T., & Ahmed, K. (2018). Flood susceptibility assessment in Kelantan river basin using copula. International Journal of Engineering and Technology, 7(2), 584-590.

• Ologunorisa, T. E., & Abawua, M. J. (2005). Flood risk assessment: A review. Journal of Applied Sciences and Environmental Management, 9(1), 57-63.

• Ouma, Y., & Tataeishi, R. (2014). Urban flood vulnerability and risk mapping using integrated multi-parametric AHP and GIS: Methodological overview and case study assessment. Water, 6(6), 1515-1545. https://doi.org/10.3390/w6061515

• Qi, H., & Altinakar, M. S. (2011). A GIS-based decision support system for integrated flood management under uncertainty with two dimensional numerical simulations. Environmental Modelling and Software, 26(6), 817-821. https://doi.org/10.1016/j.envsoft.2010.11.006

• Razandi, Y., Pourghasemi, H. R., Neisani, N. S., & Rahmati, O. (2015). Application of analytical hierarchy process, frequency ratio, and certainty factor models for groundwater potential mapping using GIS. Earth Science Informatics, 8, 867-883. https://doi.org/10.1007/s12145-015-0220-8

• Roslan, R., Omar, R. C. Hara, M., Solemon, B., & Baharuddin, I. N. Z. (2019). Flood insurance rate map for non-structural mitigation. E3S Web of Conferences, 76, Article 03002. https://doi.org/10.1051/e3sconf/20197603002

• Saadatkhah, N., Tehrani, M. H., Mansor, S., Khuzaimah, Z., & Kassim, A. (2016). Impact assessment of land cover changes on the runoff changes on the extreme flood events in the Kelantan River basin. Arabian Journal of Geosciences, 9, Article 687. https://doi.org/10.1007/s12517-016-2716-z

• Saaty, T. L. (1980). The Analytic Hierarchy Process: Planning, Priority Setting. McGraw-Hill.

• Sar, N., Chatterjee, S., & Adhikari, M. D. (2015). Integrated remote sensing and GIS based spatial modelling through analytical hierarchy process (AHP) for water logging hazard, vulnerability and risk assessment in Keleghai river basin, India. Modeling Earth Systems and Environment, 1, Article 31. https://doi.org/10.1007/s40808-015-0039-9

• Seejata, K., Yodying, A., Wongthadam, T., Mahavik, N., & Tantanee, S. (2018). Assessment of flood hazard areas using analytical hierarchy process over the Lower Yom Basin, Sukhothai Province. Procedia Engineering, 212, 340-347. https://doi.org/10.1016/j.proeng.2018.01.044

• Sharir, K., Rodeano, R., & Mariappan, S. (2019). Flood susceptibility analysis (FSA) using analytical hierarchy process (AHP) model at The Kg. Kolopis area, Penampang, Sabah, Malaysia. Journal of Physics: Conference Series, 1358(1), Article 012065. IOP Publishing. https://doi.org/10.1088/1742-6596/1358/1/012065

• Suriya, S., & Mudgal, B. V. (2012). Impact of urbanisation on flooding: The Thirusoolam sub watershed - A case study. Journal of Hydrology, 412, 210-219. https://doi.org/10.1016/j.jhydrol.2011.05.008

• Tan, M. L., Yusop, Z., Chua, V. P., & Chan, N. W. (2017). Climate change impacts under CMIP5 RCP scenarios on water resources of the Kelantan River Basin, Malaysia. Atmospheric Research, 189, 1-10. https://doi.org/10.1016/j.atmosres.2017.01.008

• Tariq, M. A. U. R., Farooq, R., & van de Giesen, N. (2020). A critical review of flood risk management and the selection of suitable measures. Applied Sciences, 10(23), Article 8752. https://doi.org/10.3390/app10238752

• Wang, J., Hu, C., Ma, B., & Mu, X. (2020). Rapid urbanization impact on the hydrological processes in Zhengzhou, China. Water, 12(7), Article 1870. https://doi.org/10.3390/w12071870

• Wong, C., Venneker, R., Uhlenbrook, S., Jamil, A., & Zhou, Y. (2009). Variability of rainfall in Peninsular Malaysia. Hydrology Earth System Science Data Discussions, 6(4), 5471-5503. https://doi.org/10.5194/hessd-6-5471-2009

• Wu, Y., Zhong, P. A., Zhang, Y., Xu, B., Ma, B., & Yan, K. (2015). Integrated flood risk assessment and zonation method: A case study in Huaihe River basin, China. Natural Hazards, 78, 635-651. https://doi.org/10.1007/s11069-015-1737-3

• Xiao, Y., Yi, S., & Tang, Z. (2016). GIS-based multi-criteria analysis method for flood risk assessment under urbanisation. In 2016 24th International Conference on Geoinformatics (pp. 1-5). IEEE Publishing. https://doi.org/10.1109/GEOINFORMATICS.2016.7578963

• Zulkafli, Z., Yusuf, B., & Nurhidayu, S. (2021). Assessment of streamflow simulation for a tropical forested catchment using dynamic TOPMODEL - Dynamic fluxEs and ConnectIvity for predictions of HydRology (DECIPHeR) framework and generalised likelihood uncertainty estimation (GLUE). Water, 13, Article 317. https://doi.org/10.3390/w13030317

• Alias, N. E., Salim, N. A., Taib, S. M., Yusof, M. B. M., Saari, R., Ramli, M. W. A., Othman, I. K., Annammala, K. V., Yusof, H. M., Ismail, N., Yuzir, A., & Blenkinsop, S. (2020). Community responses on effective flood dissemination warnings - A case study of the December 2014 Kelantan Flood, Malaysia. Journal of Flood Risk Management, 13(S1), Article e12552. https://doi.org/10.1111/jfr3.12552

• Bronstert, A., Niehoff, D., & Bürger, G. (2002). Effects of climate and land-use change on storm runoff generation: Present knowledge and modelling capabilities. Hydrological Processes, 16(2), 509-529. https://doi.org/10.1002/hyp.326

• Burby, R. J., Deyle, R. E., Godschalk, D. R., & Olshansky, R. B. (2000). Creating hazard resilient communities through land-use planning. Natural Hazards Review, 1(2), 99-106. https://doi.org/10.1061/(ASCE)1527-6988(2000)1:2(99)

• Chen, H., Ito, Y., Sawamukai, M., & Tokunaga, T. (2015). Flood hazard assessment in the Kujukuri plain of Chiba prefecture, Japan, based on GIS and multicriteria decision analysis. Natural Hazards, 78(1), 105-120. https://doi.org/10.1007/s11069-015-1699-5

• de Brito, M. M., & Evers, M. (2016). Multi-criteria decision-making for flood risk management: A survey of the current state of the art. Natural Hazards and Earth System Sciences, 16(4), 1019-1033. https://doi.org/10.5194/nhess-16-1019-2016

• DID. (2014). Laporan Banjir Negeri Kelantan. Department of Irrigation and Drainage Malaysia.

• Detrembleur, S., Stilmant, F., Dewals, B., Erpicum, S., Archambeau, P., & Pirotton, M. (2015). Impacts of climate change on future flood damage on the river Meuse, with a distributed uncertainty analysis. Natural Hazards, 77, 1533-1549. https://doi.org/10.1007/s11069-015-1661-6

• Du, S., Shi, P., Van Rompaey, A., & Wen, J. (2015). Quantifying the impact of impervious surface location on flood peak discharge in urban areas. Natural Hazards, 76, 1457-1471. https://doi.org/10.1007/s11069-014-1463-2

• FAO-UNESCO. (1990). FAO-Unesco soil map of the world. World Soil Resources Report 60ISRIC. https://www.isric.org/sites/default/files/ISRIC_TechPap20.pdf

• Green, C. H., Parker, D. J., & Turnstall, S. M. (2000). Assessment of flood control and management options. World Commission on Dams. https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.467.4860&rep=rep1&type=pdf

• Jaafar, A. S., Sidek, L. M., Basri, H., Zahari, N. M., Jajarmizadeh, M., Noor, H. M., Osman, S., Mohammad, A. H., & Azad, W. H. (2016). An overview: flood catastrophe of Kelantan watershed in 2014. In W. Tahir, S. H. A. Bakar, M. A. Wahid, S. R. M. Nasir & W. K. Lee (Eds.), ISFRAM 2015 (pp. 17-29). Springer. https://doi.org/10.1007/978-981-10-0500-8_2

• Kaoje U. I., Rahman, M. Z. A., Idris, N. H., Razak, K. A., Rani, W. N. M. W. M., Tam, T. H., & Salleh, M. R. M. (2021). Physical flood vulnerability assessment using geospatial indicator-based approach and participatory analytical hierarchy process: A case study in Kota Bharu, Malaysia. Water, 13(13), Article 1786. https://doi.org/10.3390/w13131786

• Kazakis, N., Kougias, I., & Patsialis, T. (2015). Assessment of flood hazard areas at a regional scale using an index-based approach and analytical hierarchy process: Application in Rhodope-Evros region, Greece. Science of the Total Environment, 538, 555-563. https://doi.org/10.1016/j.scitotenv.2015.08.055

• Mudashiru, R. B., Sabtu, N., Abdullah, R., Saleh, A., & Abustan, I. (2022). A comparison of three multi-criteria decision-making models in mapping flood hazard areas of Northeast Penang, Malaysia. Natural Hazards, 112, 1903-1939. https://doi.org/10.1007/s11069-022-05250-w

• Murali, M. R., Ankita, M., Amrita, S., & Vethamony, P. (2013). Coastal vulnerability assessment of Puducherry coast, India, using the analytical hierarchical process. Natural Hazards and Earth System Sciences, 13(12), 3291-3311. https://doi.org/10.5194/nhess-13-3291-2013

• Nashwan, M. S., Ismail, T., & Ahmed, K. (2018). Flood susceptibility assessment in Kelantan river basin using copula. International Journal of Engineering and Technology, 7(2), 584-590.

• Ologunorisa, T. E., & Abawua, M. J. (2005). Flood risk assessment: A review. Journal of Applied Sciences and Environmental Management, 9(1), 57-63.

• Ouma, Y., & Tataeishi, R. (2014). Urban flood vulnerability and risk mapping using integrated multi-parametric AHP and GIS: Methodological overview and case study assessment. Water, 6(6), 1515-1545. https://doi.org/10.3390/w6061515

• Qi, H., & Altinakar, M. S. (2011). A GIS-based decision support system for integrated flood management under uncertainty with two dimensional numerical simulations. Environmental Modelling and Software, 26(6), 817-821. https://doi.org/10.1016/j.envsoft.2010.11.006

• Razandi, Y., Pourghasemi, H. R., Neisani, N. S., & Rahmati, O. (2015). Application of analytical hierarchy process, frequency ratio, and certainty factor models for groundwater potential mapping using GIS. Earth Science Informatics, 8, 867-883. https://doi.org/10.1007/s12145-015-0220-8

• Roslan, R., Omar, R. C. Hara, M., Solemon, B., & Baharuddin, I. N. Z. (2019). Flood insurance rate map for non-structural mitigation. E3S Web of Conferences, 76, Article 03002. https://doi.org/10.1051/e3sconf/20197603002

• Saadatkhah, N., Tehrani, M. H., Mansor, S., Khuzaimah, Z., & Kassim, A. (2016). Impact assessment of land cover changes on the runoff changes on the extreme flood events in the Kelantan River basin. Arabian Journal of Geosciences, 9, Article 687. https://doi.org/10.1007/s12517-016-2716-z

• Saaty, T. L. (1980). The Analytic Hierarchy Process: Planning, Priority Setting. McGraw-Hill.

• Sar, N., Chatterjee, S., & Adhikari, M. D. (2015). Integrated remote sensing and GIS based spatial modelling through analytical hierarchy process (AHP) for water logging hazard, vulnerability and risk assessment in Keleghai river basin, India. Modeling Earth Systems and Environment, 1, Article 31. https://doi.org/10.1007/s40808-015-0039-9

• Seejata, K., Yodying, A., Wongthadam, T., Mahavik, N., & Tantanee, S. (2018). Assessment of flood hazard areas using analytical hierarchy process over the Lower Yom Basin, Sukhothai Province. Procedia Engineering, 212, 340-347. https://doi.org/10.1016/j.proeng.2018.01.044

• Sharir, K., Rodeano, R., & Mariappan, S. (2019). Flood susceptibility analysis (FSA) using analytical hierarchy process (AHP) model at The Kg. Kolopis area, Penampang, Sabah, Malaysia. Journal of Physics: Conference Series, 1358(1), Article 012065. IOP Publishing. https://doi.org/10.1088/1742-6596/1358/1/012065

• Suriya, S., & Mudgal, B. V. (2012). Impact of urbanisation on flooding: The Thirusoolam sub watershed - A case study. Journal of Hydrology, 412, 210-219. https://doi.org/10.1016/j.jhydrol.2011.05.008

• Tan, M. L., Yusop, Z., Chua, V. P., & Chan, N. W. (2017). Climate change impacts under CMIP5 RCP scenarios on water resources of the Kelantan River Basin, Malaysia. Atmospheric Research, 189, 1-10. https://doi.org/10.1016/j.atmosres.2017.01.008

• Tariq, M. A. U. R., Farooq, R., & van de Giesen, N. (2020). A critical review of flood risk management and the selection of suitable measures. Applied Sciences, 10(23), Article 8752. https://doi.org/10.3390/app10238752

• Wang, J., Hu, C., Ma, B., & Mu, X. (2020). Rapid urbanization impact on the hydrological processes in Zhengzhou, China. Water, 12(7), Article 1870. https://doi.org/10.3390/w12071870

• Wong, C., Venneker, R., Uhlenbrook, S., Jamil, A., & Zhou, Y. (2009). Variability of rainfall in Peninsular Malaysia. Hydrology Earth System Science Data Discussions, 6(4), 5471-5503. https://doi.org/10.5194/hessd-6-5471-2009

• Wu, Y., Zhong, P. A., Zhang, Y., Xu, B., Ma, B., & Yan, K. (2015). Integrated flood risk assessment and zonation method: A case study in Huaihe River basin, China. Natural Hazards, 78, 635-651. https://doi.org/10.1007/s11069-015-1737-3

• Xiao, Y., Yi, S., & Tang, Z. (2016). GIS-based multi-criteria analysis method for flood risk assessment under urbanisation. In 2016 24th International Conference on Geoinformatics (pp. 1-5). IEEE Publishing. https://doi.org/10.1109/GEOINFORMATICS.2016.7578963

• Zulkafli, Z., Yusuf, B., & Nurhidayu, S. (2021). Assessment of streamflow simulation for a tropical forested catchment using dynamic TOPMODEL - Dynamic fluxEs and ConnectIvity for predictions of HydRology (DECIPHeR) framework and generalised likelihood uncertainty estimation (GLUE). Water, 13, Article 317. https://doi.org/10.3390/w13030317