2011 年 17 巻 p. 209-214
Many rivers in Japan have serious problems which are caused by forestation on the shore of the channel. Its forestation was accelerated after the prohibition of extraction of pebble from river. In Aga River, the forestation also caused the loss of cobblestone shore, which had changed natural environment of its own.
This report describes the attempts on the restoration of cobblestone shore, by which modification of impact of water flow will be expected. It also includes the proposal for sustainable detainment of forestation by the design of channel.