Abstract-Climate change is a phenomenon that is forcing the world to adapt to a different environment. In this study, Analytical Hierarchy Process (AHP) method is combined with a Geographical Information System (GIS) for flood risk analysis and evaluation in the town of Enrile, a flood-prone area located in northern Philippines. Expert opinions, together with geographical, statistical and historical data, were collected and then processed through fuzzy membership. The AHP results showed the relative weights of three identified flood risk factors, and these results were validated to be consistent, using a standard consistency index. Using the Quantum GIS software, the factor weights from the AHP were incorporated to produce a map that is color-coded representing 5 levels of estimated flood risks. Using such a GIS weighted overlay analysis map as guide, local councils and other stakeholders can act to prepare for potential flooding when the rains come or, better yet, proactively promote appropriate land-use policy that will minimize threat to lives due to flooding.Index Terms-Analytic hierarchy process (AHP), decision support system, geographic information system (GIS), land-use policy.

Abstract-The Central Business District (CBD) of a city is the activity center of the city, typically locating the main commercial and cultural establishments, as well as acting as the center point of the city's transportation network. Flood risk assessment for a CBD is crucial for proper city planning and maintenance.In this study, we model the flood risk for the CBD of Tuguegarao City, which is located in northern Philippines. To accomplish this, we identified important flood-related factors whose data are either easily available or may be collected through some automated process that we developed. We then surveyed experts to gather their estimation of the importance of the identified factors, and then used the AHP to determine the consistency of the expert judgments as well as the relative weights of each factor. These factor weights from the AHP were applied to the gathered data, and a Quantum GIS software tool was used for visualization, producing a geo-hazard map that is color-coded representing 5 levels of estimated flood risks.Using such a GIS weighted overlay analysis map as guide, the city and municipal councils, planning agencies and other stakeholders can act to prepare for potential flooding or, better yet, proactively promote appropriate land-use policy that will minimize threat to lives due to flooding.Index Terms-Analytic hierarchy process (AHP), decision support system, geographic information system, urban flooding.