| In countries where river improvements are not sufficient、smooth evacuation from floods is important for reducing loss of life and property. However the development of flood forecasting and warning systems in these countries has not advanced properly for financial difficulties and lack of rainfall data. The authors have developed a concise flood-runoff analysis system “Integrated Flood Analysis System (IFAS)” as a toolkit for more effective and efficient flood forecasting in developing countries. IFAS implements interfaces to input not only ground-based but also satellite-based rainfall data、GIS functions to construct flood-runoff models、a default runoff analysis model、and interfaces to display output results to cope with some issues in such countries. In order that developing countries' engineer can actually forecast floods by themselves、the authors are not only developing systems、but also applying IFAS to actual basins experimentally、conducting free distribution of IFAS and holding training workshops. In a former International Conference on Hydroinformatics、the authors introduced concepts of IFAS、and main functions. This paper shows experimental study of IFAS. Satellite-based rainfall data are provided by some organizations for free of charge. Without installing ground-based rain gauges and transmission system、user only accesses the Internet and can obtain the semi-real-time rainfall data which covers the whole world by using satellite-based rainfall data. According to author’s experimental applications and verifications of IFAS、the following results are obtained. 1)Satellite-based rainfall data generally shows an underestimation compared with ground-based rainfall、and this tendency is remarkable especially at heavy rain events. 2)The accuracy of satellite-based rainfall data can be corrected to some extent based on the movement information on a rainy area. 3)Though calibration of parameters estimated by global GIS data would be required using local observational data for highly precise forecast、it is possible to build run-off analysis models including river channel network creations and primary estimations of parameters using global GIS data. In consequences、satellite-based rainfall data and GIS-estimated flood-runoff models can be reliably used to conduct flood-runoff analysis in cases with insufficient hydrological data、being needed the further improvement in accuracy. The authors hope that this system will be useful for the immediate and efficient implementation of flood forecasting and warning systems in developing countries. |
