関屋 幸一・徳山 和秀・迫 昭男・冨山 典孝*1・青山 好文
Seasonal Fluctuation of Water Quality and Estimated Value of the
Environment Based on Zoobenthos at the Kiyotake River (I)
Koichi SEKIYA, Kazuhide TOKUYAMA, Akio SAKO,
Noritaka TOMIYAMA, Yoshifumi AOYAMA
Abstract
We have examined the ASPT(Average Score Per Taxon) value and DI(Diversity Index),
and water quality in regard to the rivers of the prefecture from 1996.
In 2002
we investigated 5-points on the upper and lower parts of the Kiyotake river which
is situated in the central part of the prefecture.
The results of
the investigation were as follows.
1)The ASPT value was 5.0〜7.3,
and DI was 1.1〜3.2 at all points through the year.
2)We
compared the ASPT value in the investigation last time(1996) and this time(2002).
We found out the fact that the water quality environment was not good relatively
in this time(2002) more than the last time(1996) at all points, too. As the main
reason, the natural disturbance and the artificial influence by the human activity
increased every time the passing years were given.
3) About the correlation between
the points to proper degree and the ASPT value or DI, but there are few numbers,
each the coefficient of correlation was high. Therefore, it was thought that
the way of thinking of the points to proper degree can go on an examination for
water quality and estimated value of the environment based on zoobenthos.
Key words : ASPT, DI, zoobenthos, seasonal fluctuation
はじめに
当所では,大型底生動物(以下,底生動物と略す)による水域環境評価方法1)を用いて平成8年度から県内の河川の水質状況を,その季節的変動もあわせて調査してきた2)〜5)。今回,清武川について平成14年度から16年度までの3か年継続調査を計画した。当河川については平成8年度にも調査を実施しているが,すでに6年が経過 し,河川環境などの状況が変化していると考えられることから,その比較検討を行うためにまず初年度の調査を実施したので,その概要を報告する。
環境科学部水質科 *1現(財)県環境整備公社