Author(s): Youichi Yasuda; Pietro Beretta Piccoli Marco

Linked Author(s): Youichi Yasuda

Keywords: Stacked Boulders; Ground Sill; Habitat; Flood Control; Channelized River

Abstract: Kando River located in Shimane prefecture and Etaibetsu River located in Hokkaido prefecture, as gravel-bed river was partly constructed as a channelized river for flood control. In channelized region of Etaibetsu River, degradation of river bed and the formation of naked rocks were happened after the construction, and it was impossible for aquatic fishes to pass the winter. This paper presents practical approaches for the improvement of channelized river in both Kando River and Etaibetsu River. In Kando River, the ground sill with stacked boulders was installed for the improvement in the channelized gravel river. The balance between flood control and preservation of aquatic habitat was confirmed, and field observation might support the effect of the installation of the ground sill with stacked boulders on the improvement of channelized river. In Etaibetsu River, as the installation of boulders was difficult, the installation of the ground sill with concrete blocks was conducted. Naked rocks could be covered by transported gravels, and the flow condition around the ground sill may help for the preservation of aquatic habitat. From the point of aquatic habitat in channelized river, the flow condition passing over the ground sill with concrete blocks might be inferior by comparing the flow condition passing over the stacked boulders in normal stages.

DOI:

Year: 2020