わが国の閉鎖性海域の水環境特性分析

摘要

閉鎖性の海域は，その沿岸の持つ自然条件から人類にとって最適な居住環境を提供し，古くから漁場，産業活動の場，海上交通の拠点及びレクリエーションの場として利用され，沿岸域に住む人々の生活を支え様々な文化を育んできた。一方では，人間の活動によって海域の環境は大きな影響を受けてきた。経済成長と人口の増加によって発生する汚濁物質の量が増大し，それが流れ込み水質悪化の危機を招いた。%Human activities have a tremendous effect influence on the environment of enclosed coastal seas. Increased population and economic growth have caused increased pollution loads to those areas, leading to the degradation of water quality. Enclosed coastal seas are characterized by various factors and, accordingly, those factors should be properly considered in environmental management Those factors are classified to three categories: natural, socioeconomic and aquatic environmental factors. In this study, 25 enclosed coastal seas in Japan, in which 13 showed degradation and 12 showed improvements, have been subjected to discriminant analyses to determine the linear discriminant function of 12 factors. Twelve of the 13 degraded seas were correctly discriminated using the function of 92 % success, and eleven of the 12 improved seas were correctly discriminated with 92%success. We tested the performance of the discriminant function for using 24 enclosed coastal seas and the result ware correctly discriminated with 92% success. The linear discriminant function thus obtained was used to estimate the relative importance of the factors embedded in the function and to provide sound guidance for future environmental management