FLOOD RISK ASSESSMENT OF MAJOR RIVER BASINS IN THE PHILIPPINES

Disaster risk management is vital in strengthening the resilience to and reduction of losses brought by natural disasters. In Philippines where typhoons frequently occur, flood risk maps are essential for the protection of communities and ecosystems in watersheds. This study created flood inundation maps with climate change considerations under 2020 A1B1 and 2050 A1B1 scenarios for four major river basins in the Philippines: the Agno, Cagayan, Mindanao, and Buayan-Malungon River Basins. From these maps, the most vulnerable areas for each basin are identified using GIS mapping software. Sixteen inundation risk maps were generated, four for each river basin, in terms of built-up areas, roads, bridges, and dams. Results showed that the northern part of Cagayan River Basin and the central parts of the Agno and Mindanao River Basins are the most flood-prone areas, while the Buayan-Malungon River Basin will have no significant inundation problems. Suitable adaptation and mitigation options were provided for each river basin.