2006 年 12 巻 p. 397-402
This paper presents the results of an objective evaluation of the natural environment of the Chino River. River improvements were executed by restoring the fireflies’ natural environment in the new channel. The number of flights of fireflies was almost the same as the number before the river improvements. The observed results suggested that the river improvements had been relatively well executed to conserve the habitat of the firefly. In order to evaluate objectively, the natural environment of the four rivers in the southern part of Miyazaki were classified by the principal component analysis. The analyzed result showed that the natural environment in the new channel was classified in the state influenced by human activity. This result showed the importance of the objective evaluation.