Abstract
This study focuses on the quantitative evaluation of the effect of environmental change caused by the river restoration work. Firstly, we investigated the fish distribution as well as the distribution of riffle-pool and attached algae in the Furukou River, Yamaguchi, in which restoration work is going on. Then we applied our former model of fish preference, including the factors of water depth, velocity, food and cover, to reproduce the observed fish distribution. The model is based on the laboratory experiments. The calculated fish distribution met the observation, but was not enough. The difference between the calculation and the observation might come from:(1) the experiences do not handle preference change according to the seasons, (2) some environmental conditions in the experiments do not represent the real river and (3) the model does not take into account the change of behavioral mode of fish in a day. Taking the third point into account, a new habitat evaluation model is proposed considering the fish home range and three fish behavioral modes of feeding, resting, and hiding. This comprehensive preference model was proved to be more effective in the real river.
