| As the first step to improve the accuracy of satellite-based rainfall data using an engineering method, ICHARM proposes a self-correction algorithm without any ground-based rainfall truth data. The authors found a significant relationship between the degree of underestimation of heavy rainfall and the movement factor of rainfall field acquired by satellites. The empirical relationship was optimized for GSMaP data using flood events in the Shikoku Island of Japan and then was applied to some heavy rainfall events in the world. Then it was found the empirical formula was effective as well for the verification events as a whole. This method is effective only for heavy rainfall events at present, but the result is very promising for flood disaster mitigation since flood hazards usually occurs due to heavy rainfall.Besides, as a common toolkit software for the implementation of flood forecasting system in poorly-gauged basins in developing countries, ICHARM developed the Integrated Flood Analysis System, in short, IFAS. IFAS can utilize not only ground-based but also satellite-based rainfall data directly with the self-correction algorithm above, implemented with GIS analytical tools to construct distributed-parameter hydrological models, and with graphical input-output interfaces, which enables runoff calculation necessary for issuing flood forecasts and alerts, which leads to a realization of the concept of GFAS-streamflow of IFNet, in any river basins of the world. |
