降雨時および融雪期を含む感潮域での流量推定手法の構築

抄録

Field observation of current speed by using Acoustic Doppler Current Profiler (ADCP) in tidal river was conducted in order to propose the expression that presumes discharge, instead of the H-Q rating curve. The error margin when discharge is forecast by using it is large, because river stage in tidal river is changed by the influence of the tide and the phenomenon of the backflow appears. Yokoo (2004) proposed the method of forecasting discharge by using change rate of water level at unit time. However, the forecast of discharge that used the method is difficult at rainfall and melting of snow period.

We confirmed the phenomenon of the flow in the tidal river by the observation that used ADCP and propose a method for the presumption of discharge for the tidal river including rainfall and melting of snow period by considering the amount of the inflow from the upstream by using river stage in the upstream point.