FLASH FLOOD SUSCEPTIBILITY MAPPING USING GEOSPATIAL AND ANALYTICAL HIERARCHY PROCESS MODELING - A STUDY OF WADI HABBAN BASIN, SHABWAH, YEMEN

Abstract

 Flash flooding is a significant natural disaster that occurs in deserts (arid and semiarid) regions, resulting in extensive destruction of property and loss of life. Thus, flash flood-prone zones must be precisely mapped. “Flood-susceptibility-maps” are essential to identifying the best preventative actions to guarantee the security of a region and infrastructure. This study aims to evaluate Wadi Habban Basin's vulnerability to flash flood threats by integrating data from remote sensing, geographic information systems (GIS), and analytical-hierarchy-process (AHP). The spatial distribution of hazardous areas was assessed by the weight and reclassification of each flood factor. Ten key criteria were integrated - geomorphology, elevation, slope, rainfall, drainage density, distance to watercourse, land use and cover, soil texture, Topographic Wetness Index (TWI), and Stream Power Index (SPI) - into a Geographic Information System (GIS) platform. Using the Flood Hazard Index (FHI) analysis, which focused on the impacts of specific criteria, the maps illustrating the risks of flash floods in the Habban Valley basin were classified into five categories: 4.3% (very high), 10.2% (high), 29.4% (medium), 42.2% (low), and 13.7%. (very low).  This allowed for a more accurate assess of the impact of each factor on flood susceptibility. The study’s findings offer a foundation for mitigating flood risks and safeguarding areas adjacent to valleys.