ABSTRACT
In Japan, channelized rivers with both concrete side walls and flatbed exist, and shallow water flow is formed during normal stages. In such a condition, scouring and river bed degradation might occur during flood stages. In this paper, an optimal river cross section for both flood control and aquatic habitat is proposed by using gravel materials with 25 cm averaged diameter in prototype. In the gravel bed with 1/100 slope, gravel mount with triangular pyramid shape are installed alternately. In proposed cross section, the flow condition changes under several discharges. In accordance with water surface and velocity measurements, for a large discharge, the main flow is located at the center part, and side and bottom of channelized river can be protected from erosion. Also, the flow behind the gravel mount might be affective to preserve the emergence area for aquatic animals.
