Abstract
This paper investigated causes of grass invasion into river channels and developed the prediction model by using logistic regression analysis. The river channels analyzed was located in the middle section of the Kinugawa River. The logistic regression analysis dealt with data obtained from field observations in 2015 and 2016 using a UAV measurement. The results of the regression analysis showed that the grass invaded into the channels with the factors, in order of the past vegetation history, dimensionless tractive force/height from the normal water level, and shortest distance from river streams. The accuracy of the logistic reogession model became highest in the case including the past vegetation history as a explanatory variable. The prediction result of the model indicated good ability for the grass invasion probability with 75% of accuracy rate.
