Optimizing Mitigation Plan for Flood Hazards of Local Government using GIS-Based Approach: A Proposed Design of Flood Hazard Map with As-built Mapping of Riverside Area in Sitio Ilayang Pantay 1, Brgy. Sapaan, Atimonan, Quezon

Floods were on of the most harmful natural calamities, which resulted in a large number of fatalities, property damage, and economic disruption. Barangays were particularly vulnerable, the most minor local government unit in the Philippines. Many people in Sitio Ilayang Pantay1, Barangay Sapaan, Atimonan, lived in riverfront areas that were at risk of flooding; consequently, flooding became a continual worry. This study aimed to optimize flood mitigation strategies using Geographic Information System (GIS).These maps played a key role in chance evaluation and the improvement of GIS-based emergency reaction technologies. Using cutting-edge surveying equipment and GIS interpretation techniques, the study used the Research and Development (R&D) approach to conduct surveys to identify topographic features, determine property boundaries, and gather elevation data. GNSS receiver instrument was used to map river boundaries and collect vital elevation data for the research. Creating accurate maps of flood risk and improving planning and response to disasters were the main goals. The Likert Scale was used to assess the effectiveness of the flood hazard map, and survey questionnaires were also distributed to 30 barangay authorities and citizens. Strong agreement was found in the feedback about the effectiveness, efficiency, and accuracy of the maps, which even common inhabitants could grasp. The community's flood-prone zones could be found on these maps, which was a great help for upcoming disaster management initiatives.