河川の環境管理を推進するための課題と方向性

抄録

Environmental management of rivers (EMR) aims conservation and restoration of the natural and beautiful rivers. However, there are still many problems for EMR, e.g. to set environmental target and to obtain abundant environmental data. To promote EMR, this paper reviews the practice of EMR and discusses the issues and directions of EMR. The EMR can be divided into four parts, i.e. understanding of environmental status, appraisal of data, establishment of environmental target and implementation of management. Appraisal of data still needs the improvement of the basic science and methodology. Above all, establishment of environmental target remains the biggest difficulties for EMR. Therefore, we proposed to set the basic principle of EMR, “Preserve the existing environment and possibly improve it” instead of setting environmental target. To practice the EMR following the principle above, we propose to designate “good site”, where relatively ecologically a good site locates in the river. The “good site” is conserved and the other sites are restored referring “good site” as much as possible. We discussed the EMR based on this principle.