FLOOD RISK MAPPING AND IMPACTS ASSESSMENT IN KEEA MUNICIPALITY

Abstract

Flood is the most disastrous natural disaster in the world due to its devastating effects that endanger lives and cause property damage to the affected areas. Flood events are alarmingly increasing all over the world; and despite the recent efforts towards mitigation and management, vulnerability to flood damages is likely to continue to grow. This research mainly aimed at identifying areas at risk of flooding through the application of two different models namely the Analytical Hierarchy Process (AHP) and Fuzzy Analytical Hierarchy Process (FAHP) using remote sensing data (RS) and Geographical Information System (GIS), extract 2022 flood extent using Sentinel-1 SAR product, and assess the impacts of floods on communities. The study was conducted in the Komenda Edina Eguafo Abrem Municipality, Ghana, and consisted of the use of fourteen predicting factors for the flood risk mapping and 300 respondents for the field data collection. The results indicated that the FAHP model performed best for the risk mapping in the study area disclosing a 94.3% prediction rate compared to the AHP model (86.4%). Moreover, the flood inundation extent of 2022 covered 4,553 hectares of the study area with 19% of the urban areas being inundated. The findings revealed a staggering 90% of respondents within flood-prone communities experienced flooding in the past 5 years. Torrential rainfall emerged as the primary flood trigger, often leading to rivers overflowing and causing extensive damage. Approximately 74% and 56% of respondents reported property and agricultural damage, respectively, ranging from building collapses to crop and livestock destruction, along with associated psychological effects. Over 50% of respondents prioritized building flood steps and reconstructing damaged houses with cement as a coping mechanism with sociocultural barriers and limited access to climate information hindering mitigation and adaptation efforts. Respondents prioritized community education, early warning systems, and financial support to address these challenges, emphasizing the importance of building adaptive capacities in flood-prone communities. The outcome of this study can be used by planners and policymakers to implement different management and mitigation measures with a view to the local environment.