Spatial Simulation for Flood Disaster Forecasting: A Geospatial Technology-based Group Analytic Hierarchy Process Approach

Group Analytic Hierarchy Process (GAHP) is integrated with Geographic Information System (GIS) and remote sensing to help in simulating the flood likely areas based on a total number of five set of criteria/factors believed to be triggering flood generation in the study area. Two categories of experts namely hydrologists and geologists were considered. Saaty’s 1-9 scale of preference was employed in rating each factor’s influence in flood generation and the ratings from the experts were aggregated using a Geometric Mean method. Having done with the aggregation, priory weights of the factors were calculated; weights were further normalized through the Analytic Hierarchy Process (AHP). The result was further integrated into GIS system for spatial simulation of the likely flood areas. In validating the robustness of the result, known Flood Extent Extraction Model developed based on a Neural Network Algorithm embedded in ENVI 4.8 software was used. The result of the overlay carried out in ArcGIS 9.3 software displayed a significant match with what is on ground.