フィリピン・カガヤン川流域における現行の洪水予測手法の水文学的課題と改善に向けての提案

抄録

The Cagayan River basin which is largest river basin in the Philippines has severe problems of flood management. Regarding to flood forecasting, the water level correlation method has been applied to flood management as the existing method of the Cagayan River basin during flooding. However, accuracy of water level correlation method is not sufficient, because it cannot include the spatial distribution of rainfall and influence of flood control such as dam operation.

In this study, accuracy of existing method is evaluated and hydrological challenges are clarified for establishment of effective flood early warning system. Not only evaluation of existing method, flood forecasting method based on IFAS which is the distributed hydrological model developed by ICHARM et al., is also proposed. The advantages of IFAS are verified in terms of forecasting accuracy and lead-time. Moreover, the potency of satellite-based rainfall as the supplementary information is examined for considering the spatial distribution of rainfall.