2022 Volume 78 Issue 1 Pages 1-8
The rainfall events cause flash floods and drowning accident occurs in an underground area. Therefore, it is very important to study the falling down risk when people walk through the flood water. In this study, the flume experiments were conducted using the human body model (1/6 scale). We changed the channel width, number of people, direction of body and body posture. The drag force exerted on the human body was measured in a narrow channel which assumes the underground pass. The data showed that the drag force acting on the body increases in the narrow pass due to the backwater rise. We revealed that the falling down risk when people walk through the flood water becomes larger than the risk when people walk toward the flood water. The risk of being washed away in the lying position by water flow was also examined.
