降雨遮断モデルによる実時間洪水予測精度の高度化に関する検討

抄録

The risk of heavy rainfall is emphasized and real-time flood prediction is become to an important method for river management. It is most important problem to predict discharge ratio / effective rainfall which is different in each event for more improvement of real-time flood prediction. Infiltration capacity, fixed rate etc. are used well in order to determine effective rainfall. On the other hands, rainfall interception in Japanese forest is 10 to 25 %. It is an important factor to affect to discharge ratio, however, not emphasized in rainfall-runoff analysis. In this paper, the advancement of prediction method of effective rainfall with rainfall interception model is investigated. The distributed rainfall interception model considered evaporation process based on micro meteorological situation and forest structure is developed. The direct discharge ratios, which are obtained by observed hydrograph separation, are compared with the simulated results by the interception model for 10 rainfall events in 2009. Positive relationship (R=0.90) was shown between observed and simulated discharge ratio for the events without previous rainfall, i.e. almost never influence of infiltration loss. It was found that the possibility of prediction of discharge ratio using interception model. The improvement of real-time runoff prediction is expected with consideration of the interception method proposed in this paper.