History and technical characteristics of historical sabo facilities in Bannai River, Hikagesawa and Kamakurasawa River, Niigata Prefecture

Abstract

Niigata prefecture in Central Japan, the first auxiliary erosion and sediment control project was started at Hikagesawa, Bannai river in 1921. This river is a tributary of Yashiro river included in the Seki river system that flows through Myoko city. Afterwards, construction for erosion and sediment control in Kamakurasawa river, which is a tributary of Uono river included in the Shinano river system, was carried out from 1927. However, the historical background of construction in both facilities has not been investigated clearly. Therefore, the author performed document and facility investigation regarding Hikagesawa, Bannai river and Kamakurasawa river, and then clarified the historical background of construction. As a result, we found that Maruo Ikeda and Masao Akagi, who are famous Japanese engineers specializing in erosion and sediment control technology, led the project and introduced the latest technology at that time in the early phase of erosion and sediment control project in Niigata prefecture. Both facilities have strong influence on subsequent facility plans for erosion and sediment control in Niigata prefecture. In this study, we revealed not only the historical background of construction of facilities for erosion and sediment control at Hikagesawa, Bannai river and Kamakurasawa river but also the technological features of constructed facilities for erosion and sediment control.