Flood risk assessment in Surigao City: Developing of flood depth-damage-velocity functions

Surigao City is generally a flood prone area due to its geographical make-up, for it is coastal and riverine city. Constant rainfall within the area outs the city\u27s structures in risk of flood hazard, thus a need of a flood risk assessment. The researchers conducted a flood risk assessment of Barangay Washington and Barangay San Juan in terms of its structure, namely its residential households. Using GIS and GPS based programs the houses were tagged and marked in lieu of its structural make-up as well as a general visual assessment namely the GENCON map, analysis was then done in par with provided flood models for its structural make-sup as well as a general visual assessment namely GENCON map, analysis was then done in par with provided flood models for its structural strength. Thus, damage-depth velocity functions and flood risk assessment grading (FRAG) are produced. Integrating the results from the functions, the researchers created damage maps that show the impact of a certain flood event to each of the houses, depending on its location and tagged data. The results of the flood risk assessment of the study shows that the residential structures have flow flood risk, despite the high flood height and frequency of the study area, due to low flood velocities. This conclusion was based on the pre-existing flood maps with more accuracy in terms of flood velocity as well as integration with the GENCON map