PROPOSAL OF A NEW APPROACH CONSERVING NATURAL ENVIRONMENT ON CHANNEL EXCAVATION

Abstract

Channel excavation has been widely applied in most of rivers managed by Ministry of Land, Infrastructure and Transport. Most of channel excavation are conducted in floodplain higher than normal water level, in order to avoid the influence instream ecosystem. However, as plant community on floodplain is disappeared temporarily in the area of channel excavation, the impact should be evaluated adequately and it would be necessary to mitigate the impact if important plant community for conservation is influenced. This study proposes a conservation process on channel excavation implementation, by utilizing" National Censes on River Environment". species in terms of conservation of biodiversity are chosen from the viewpoint of rare species, typical species, peculiar spices and exotic spices, and chosen species are associated with plant community based on the available data on National Censes on River Environment. Conservation area for channel excavation can be recognized easily, by utilizing spatial distribution of plant community in terms of conservation of biodiversity. This mapping process provides river manager with the area where we should pay attention from the viewpoint of conservation of biodiversity.