積雪地域にあるダムの放流操作への積算予測雨量の活用について

抄録

To improve the flood control of a dam, the use of rainfall forecasts in dam water release operation was examined. First, the advantages and the characteristics of errors of the forecasted cumulative rainfall were elucidated through comparison of the accuracy of such rainfall and the forecasted time series rainfall for the Ishikari River basin. Next, trial operation using the forecasted cumulative rainfall was performed for a snowmelt flood at Hoheikyo Dam in Sapporo. In the operation the necessity of releasing the reservoir water was determined by comparing the inflow calculated based on the forecasted cumulative rainfall and the space available in the reservoir, and advance release of reservoir water and flood control was performed. For the snowmelt flood, the water release operation based on the forecasted cumulative rainfall was found to be effective in improving the flood control of the dam.