Flood risk assessment using analytical hierarchy process: A case study from the Cheliff-Ghrib watershed, Algeria

Abstract

Flooding is one of the most devastating natural disasters brought on by climate change in North Africa. The occurrence of flood risk is due to a combination of natural and man-made variables, necessitating a better knowledge of its spatial scope. The goal of this study is to locate and map flood-prone regions in the Cheliff-Ghrib watershed. Within the ArcGIS interface, this study is based on the integration of multi-criteria data such as slope, drainage density, type of soil, rainfall, population density, land use and sewer system density. For flood risk assessment and mapping, the Analytic Hierarchy Process (AHP) technique was employed as a multi-criteria analysis, allowing the integration of numerous factors under two criteria namely, hazards and vulnerability. The AHP flood risk map reveals that areas at high and extremely high risk of flooding cover 22.5% of the study area. According to the findings, the Cheliff-Ghrib watershed is extremely vulnerable to flooding. Eight of the Chelliff-Ghrib watershed's 15 municipalities (8/15) are at high risk of flooding, necessitating the development of efficient flood mitigation solutions for future flood events.

Application of Analytical Hierarchy Process (AHP) and Multi-Criteria Evaluation (MCE) for a Case Study and Scenario Assessment of Flood Risk in the White Volta Basin of the Upper East Region, Ghana

“…The Consistency ratio (CR) is one of the most important components which is required to be determined when using AHP [34]. When the consistent ratio is below 0.1, then the said matrix is considered to have an acceptable consistency.…”

“…Paired comparison matrix determined by imposing judgments; Assigning values to subjective judgments and calculating the relative weights of each criterion; Synthesize judgments to determine the priority variables; Check the consistency of assessments and judgments [34], and this approach is summarized in (Figure 3).…”

Flood Disaster Risk Assessment in Wuhan City Based on GIS Analysis and Indicator Ranking Using Random Forest

“…They designed a flood risk index to understand the role of risk-driving factors at the local level. Mokhtari [9] utilized the Analytic Hierarchy Process (AHP) to integrate multi-criteria data, such as slope, river network density, soil type, rainfall, population density, land use type, and drainage system density, to identify and map flood-prone areas in the Cheliff-Ghrib watershed. Abdrabo [10] conducted a study in a coastal city in Egypt, where they developed and assessed a urban flood vulnerability index based on the exposure, susceptibility, and resilience of the city to urban flooding.…”