Spatiotemporal Mapping of Urban Flood Vulnerability under Climate and Land Use Change: A Multi-Criteria GIS-Based Assessment in Nangarhar, Afghanistan

Afghanistan, a semi-arid region with limited prior research. This study presents an integrated assessment of urban flood vulnerability by analyzing land use land cover change (LULCC), climate variability, and geophysical factors using remote sensing, GIS, and multi-criteria decision analysis. Landsat imagery indicates built-up areas increased from 124 km² in 2004 to 180 km² in 2024, while agricultural land decreased from 1,978 km² to 1,883 km². Climate data show rising temperatures and intensifying rainfall, exacerbating flood hazards. Geospatial analysis of elevation, slope, drainage density, and proximity to water bodies highlights the high vulnerability of low-lying areas. The Analytical Hierarchy Process (AHP) integrates diverse flood risk factors to produce accurate flood hazard maps. High and very-high flood susceptibility zones expanded from 5,706 km² in 2004 to 5,985 km² in 2024, whereas low-susceptibility zones declined from 131 km² to 112 km². These results underscore the need for adaptive land use planning, resilient drainage systems, and community-based flood risk reduction. The study provides actionable insights for sustainable flood management and demonstrates the value of combining GIS, remote sensing, and multi-criteria analysis in data-scarce, conflict-affected regions.