Verification of Ship-generated Wave Countermeasures toward Conservation and Restoration of Reeds in the Downstream of the Arakawa River

Abstract

In the downstream of the Arakawa river, reeds decreased growing areas due to flood channel construction and erosion caused by ship-generated waves. Therefore, the countermeasures for the conservation and restoration of reed comunity have been conducted for twenty years.

This report describes the maintenance effect by investigating the time changes in topography and reed community in the Komatsugawa and Senju Sakuragi Districts.

In the Komatsugawa District, the increase in the reed community and the species number of the benthic animals were confirmed by the effect of countermeasures , The reeds are protected by the wave energy dissipating facilities at the Senju Sakuragi District. Since any expansion of reed community was not found, tree management and reed transplantation are planned for the recovery of reed community.