A Study on Diversion Weir Height for Maintaining Two-way Channel

Abstract

Attempts have been made to reconnect the current river channel (which was previously straightened in river improvement work) with previous meanders in channels remaining as oxbow lakes, on the Shibetsu River in the northeastern part of Japan. The purpose of this project is to restore the rich natural environment that had been lost in the straightening, while maintaining the channel ’s function of enabling oodwater to ow away safety. Such a channel is known as a" two-way channel "as it has two passages, and has a diversion weir installed downstream from the divergence point to facilitate the ow of water to the meandering side. This study presents a method of creating a computational grid for two-dimensional analysis of such a two-way channel. This method also enables detailed advance verification of the weir height required for long-term management of river channels with divergence and con uence points.