Development of Flood Risk Assessment Method for Data-Poor River Basins: a Case Study in the Pampanga River Basin, Philippines (PAP014383)
Badri Bhakta Shrestha, Toshio Okazumi, Mamoru Miyamoto, Hisaya Sawano
Impact of climate change on flood risk
In recent years, floods frequently occur in the world, which cause serious damage of properties and loss of lives. An assessment of flood risk in the river basin is thus very important for development activities and river basin management. In this study, the flood damage assessment method was developed for the assessment of flood risk in data-poor river basins by using physical based numerical model, satellite-based information and socio-economic factors. The Pampanga river basin of the Philippines was selected for the case study. For the flood damage assessment, the hazard characteristics such as flood depth and duration were computed by using Rainfall Runoff Inundation (RRI) model. Agriculture and household which are major exposures in the flood prone areas were taken into account for the flood damage assessment. The potential damages of agriculture were estimated by using the damage function of agriculture and flood characteristics. The damage functions of agriculture for its each growing stages were defined as the function of flood depth and duration. Field investigation and questionnaire surveys were conducted at the selected Barangays (Villages) in the Pampanga river basin to develop methodology for household damage estimation. The appropriate damage functions for household building and assets damages were developed based on the flood and household characteristics. The estimated damages of agriculture and household were consistent with the reported values. The developed method can be applied in other river basins where damages data are poorly available.