水文モデルと底生動物の生息場モデルを用いた河川健全度パターンの評価

抄録

 We built a model to estimate catchment-scale stream integrity using a hydrothermal model and biomonitoring techniques. First, we prepared habitat suitability indices of 32 benthic macroinvertebrates developed using the hydrothermal simulation and several landscape variables. We also adopted multiple metrics as stream integrity; average score per taxon (ASPT), EPT, benthic index of biotic integrity (B-IBI), Shannon-Weiner's diversity index and principal component scores. Most of the integrity metrics exhibited increasing trends along with elevational gradients, while ASPT showed a somewhat different trend. The integrity score of ASPT varied in developed area, and increased with catchment area even though other metrics such as EPT and B-IBI showed opposite pattern. Finally, according to the result of one-way analysis of variance, land-use strongly contributed variation of the integrity metrics within the catchment, suggesting a need of further consideration in outcomes where applying integrity metrics to another geographical domain because it is surely comprised of different land-use.