Based on field data of inundated depth and inundated flow velocity that is estimated by using the Bernoulli's theorem and the inundated depth, fundamental characteristics of relation between the inundated flow velocity and the inundated depth is examined, and simple and practical relations are presented for two cases that the inundated flow velocity would exert the largest and smallest fluid forces on structures and so on. Fundamental characteristics of velocity coefficient that is newly defined and implicitly included in the relations and distribution of waterline around/on typical objects such as square pillar, corn and column are also examined through hydraulic experiments.
