Integrating spatial cost path and multi-criteria analysis for finding alternative routes during flooding

Route accessibility is essential infrastructure, facilitating more convenient transit for individuals. Nonetheless, the seasonal monsoon can lead to flooding and impair the accessibility of local transportation, especially in hilly-lowland areas. This study aims to investigate an alternative route access for safe travel from Kota Marudu to Kota Kinabalu, Sabah, during the floods with GIS path analysis and MCDA method. The slope, rainfall, land cover /land use (LULC), distance from the river and river density were utilized to construct the flood susceptibility map using Analytic Hierarchy Process (AHP), while path analysis was applied to find the accessible and safe routes. There are two other routes in the study region, one of which may be utilized as a suitable route. A new route should be considered to create roads in the higher area. The alternate route map suggested in the study is a beneficial tool as caution during the rainy season. As the flood's extent is simply an estimate, it is only possible to forecast the event, and sometimes can result in unexpected tragedy.