Environmental Evaluation of Southern Area of Boso Peninsula by BMWP Score Method

摘要

Chemical and biological quality surveys are adapted to investigate river pollution world widely. Only target parameters are indicated in chemical water quality, however, contamination by unidentifiable substances can also be indicated in biological quality surveys. Therefore, in EC and USA, biological water quality surveys such as the BMWP method are often used to assess river water environment. In Japan, when evaluating river environment, chemical water quality survey has been adapted as main investigation method, but biological water quality survey has not, as well as in Chiba prefecture. Then, the Environment Agency of Japan improved the BMWP method in EC and USA to Japanese benthic organisms, and created the "BMWP score method" to widely carry out in Japan. In this study, the river environment evaluation using the biological index was carried out for Kamo river which flows down the southern of Boso peninsula, and the river environment map in the Boso peninsula was constructed. As results, Kamo River was assessed as somewhat clean water enviroment, and was indicated that there was a tendency that water pollution is progressing from upstream to downstream.