閉鎖性水域の水質保全計画に関する研究 児島湖に関するケーススタディー

Abstract

The water pollution of Kojima Lake has become serius problems for the agricultural water use and fishery. In order to improve the water pollution, a regional sewage treatment system which adopts advanced treatments has been costructed and started the treatment from march, 1989. But it takes more than 15 years to complete the system.The purposes of this study are to assess measures for water pollution control in Kojima Lake. and to consider the method of an environmental impact assessment of the regional sewage treatment system. The measures to be assessed are both construction of treatment facilities and water quality improvement by commnity action and aquatic plants.The main results are as follows. The predicted water quality considerably depends on the predicted pollutant loadings from the lake basin. Neverthless, the accuracy of them is not so high because of inaccuracy of basic units of loadings and future pollutant sources predicted. Therefore, the accurate assessment needs the detailed consideration on basic loadings and pollutant sources before prediction of water quality by models. Before completion of the system, community action have fairly much effect on the water quality if most of inhabitants participate.