Study on Support for Dam Management

Recently while various areas throughout Japan have often had quick and unexpected local heavy rain, Hokkaido has also had a lot of the same type of rain. Since rain patterns are not what they used to be, water volume flowing into the dam can suddenly increase even in the cases of rainfall information from gauging and precipitation stations located upsteram of dams, where it is not confirmed.

The Civil Engineering Research Section has conducted research activities for developing the rainfall prediction system for supporting dam management and establishing the anlysis system of runoff suitable for Hokkaido.

The water volume discharged by the dam is decided on the water volume flowing into the dams, which dam management engineers predict based on the data from the Japan Meteorological Agency, gauging and precipitation stations. We hope the prediction accuracy of water volume flowing into the dam will be improved if we predict the rainfall by ourselves and consider the result from the anlysis of how rainfall flows into the rivers, as well.

Although there is a rainfall prediction system in the Japanese Meteorological Agency, the Numerical Weather Forecasting and Analysis System (NuWFAS) developed by Central Research Institute of Electric Power Industry can set models freely. Therefore we can develop a rainfall prediciton system for the next 6 - 72 hours which considers the local characteristics of Hokkaido. Furthermore, we can also establish a runoff anlysis system suitable for Hokkaido by using the Hydrological Evaluation with Evapotranspiration Modeling System (HYDREEMS) which considers the plant evapotranspiration process.