GIS-Based Vulnerability Evaluation of Climate Change Hazards of Flood and Erosion Using an Integrated IVFRN-DEMATEL-ANP Decision Model

Abstract

Climate change is an evident environmental problem today, with the rise in the incidence rate and intensity of hazards such as floodingFlooding, heatwaves, droughtDrought, tornadoes, erosionsErosion, etc., affecting every part of the world. In Anambra State, climate change effects are a threat to food security as floodFlood and erosionErosion hazards destroy arable lands and crops. As such, hazard vulnerability maps of the state are required to assist hazard risk management and to address the issue of climate change across the state. Studies on the weakness of applying GISGeographic Information System (GIS) as stand-alone technique in evaluating vulnerability by researchers are established. As such, this study applied a geospatial technology based ensemble model of the Interval Value Fuzzy Rough Number (IVFRN), Decision Making Trial and Evaluation Laboratory (DEMATEL), and Analytical Network Process (ANP) methods in vulnerability assessmentVulnerability Assessment of climate change hazards of flood and erosion. The IVFRN eliminated uncertainty in the decision making process. The DEMATEL assessed and determined the relative significance of our risk factors. The ANP determined the final weights of the factors based on their significance. The overall climatic vulnerability index map of the study area was produced by overlaying the floodFlood vulnerability map and the erosionErosion vulnerability map. The study results indicate that the state is very vulnerable to climate change effects, with about 71% classified as having medium and very high vulnerability zones. Anambra West was identified as been the Local Government Area (LGA) most vulnerable with about 85% of the entire area categorized as having very high and medium vulnerable zones. It is suggested that adequate drainage systems, good soilSoil conservation practices and structural and non-structural approaches should be integrated to mitigate the hazards.