2016 Volume 46 Issue 3 Pages 175-184
According to the article 16 of the Basic Environment Law, the government shall establish environmental quality standards, the maintenance of which is desirable for the protection of human health and the conservation of the living environment. Usually, an achievement rate of environmental quality standard is used as pollution control and environmental conservation policies or programs. Since designated categories have different standard values, simple achievement rate (AR) of dividing numbers of achieved points by total monitoring points cannot always explain improvement of environments. In this paper, BOD, one of living environment items in environmental quality standards for water pollution is considered as an example of methodology. This study introduced environmental factors in order to evaluate achievement of higher (or lower) category of standards by giving higher (or lower) scores, which is called a factored achievement rate (fAR). Through efforts of local governments, many monitoring points have satisfied the designated categories and sometimes even higher categories. Upgrading the categories from present designated ones, possible achievement rate can be calculated (pAR).
Similarly, an environmental index (EI), a possible one (pEI) and an adjusted one (aEI) are defined by using environmental factors and designated categories, a corrected one and an adjusted one, respectively.
The calculated results for the 47 prefectures of Japan show that the three achievement rates and present environmental indices could explain present environmental situation and suggest future water environmental policies for each prefecture.
