| HQ curve (rating curve) is usually adopted in Japan to calculate water discharge in rivers on a continuous basis from water level observed by water gauges in the same river section, although it has been said that this curve does not consider the effect of water surface slope and river-bed elevation change during flooding. Recently, HK curve is proposed to take the effect of water surface slople into consideration, but the applicability of this curve has not been confirmed actually. So the authors tried to verify the suitableness of this curve in the actual rivers during flooding. As the result, HK curve method can calculate accurate discharge in rivers without river-bed change, but in rivers with river-bed change, this method doesn't show better result than that of HQ curve method. It is shown that this result is caused by the lack of the consideration about the river-bed change. |
