Flood Vulnerability Assessment of Sujawal Taluka, Sindh, Pakistan: A GIS-Based Multi-Criteria Analysis Approach

Abstract

Flood vulnerability assessment is critical for disaster risk reduction in deltaic regions prone to recurrent flooding. This study develops a spatially explicit flood vulnerability map for Sujawal Taluka, Sindh Province, Pakistan, using an integrated approach combining the Analytical Hierarchy Process (AHP), Geographic Information Systems (GIS), and remote sensing. Seven flood-conditioning factors (rainfall, distance to river, elevation, slope, land use/land cover, NDVI, and population density) were systematically weighted using AHP (Consistency Ratio = 0.0177) and integrated through raster-based multi-criteria analysis. Results classified Sujawal into five vulnerability zones: Very Low (97.06 km², 13.7%), Low (148.89 km², 20.9%), Moderate (177.21 km², 24.9%), High (216.44 km², 30.5%), and Very High (71.02 km², 10.0%). Validation against 809,863 historical flood events confirmed model accuracy, with 40.45% of floods occurring in the High and Very High zones (collectively 40.5% of area). Population exposure analysis revealed 71,544 persons (36.05%) reside in high-risk zones. These findings provide an evidence-based roadmap for prioritizing flood mitigation investments, emergency response planning, and land-use regulation in this vulnerable Indus Delta region.