2003 Volume 2003 Issue 748 Pages 11-23
We investigated the database of fish species in the National Census on the Environment by statistical analysis. A summary of this study is given as follows. (1) The number of fish species found in Class A rivers was 183 and the major five species accounted for 50% of the total. (2) The proportion of fish species can be represented by four principal components with 0.754 of contribution rate in principal component analysis. (3) Variation of the proportion and diversity index of fish species can be quantitatively estimated by adopting classification of river morphology and segment of river longitudinal profile as explanatory indexes. (4) The diversity index of fish species has a significant correlation with the slope of river bed and the ratio of vegetated area in the river area.
