A study on the evaluation of trees' effect of reducing slope failure sediment
movement in a buffer forest zone
Toshitaka KIDOWAKI, Masanori KANEKO and Hideki TERADA
Abstract
Amid growing concerns over the natural environment and scenery of slopes in recent
years, the trees' effect of reducing slope failure sediment movement has been
drawing more attention, and more studies have been conducted aimed to establish
its quantitative evaluation. To calculate the distance of slope failure sediment
movement, we have presented equations, in this paper, which include the effect
of trees as a resistive element based upon the existing slope failure sediment
movement models. To indicate the trees' effect in the equations, we obtained its
coefficient values, using the results of experiments with buffer forest zone models.
Further, picking up some real cases of slope failure sediment movement that had
actually occurred on a slope with trees, we calculated the distance of each slope
failure sediment movement by using the equations. The calculation results indicated
that in two cases where the lower part of the slope was rather gentle with an
incline of 10 degrees, the sediment movement would stop halfway. This was found
right since the calculated value on the sediment movement distance was relatively
close to the actual measurement. Meanwhile, it was also learned that in other
four cases in which the slope was evenly inclined within the range from 33 to
36 degrees, the sediment movement would not stop.