2018 Volume 24 Pages 535-540
Frequent and High-density field observations of the underflow water adjacent to the river levee were performed by using a flow visualization system which was developed in this study. Results shows that the direction and the velocity of the underflow water adjacent to the river levee of Kiryu River had the space-temporal variation. The flow direction and velocity during the flood also showed remarkable variations. Comparison of the direction and velocity of the underflow water between before and after the flood showed that the characteristics of the underflow water changed. It indicated that the ground conditions around the borehole changed by the flood history.
