シミュレーションモデルを用いた林道計画に関する研究

Abstract

数値地形図をベースとしたモデルを用い林道の開設をシミュレーションすることで, 林道開設量と集材費の関係を求める方法について考察した。この方法では集材可能面積, 集材費, 開設費の評価値等が逐次出力されるので, 適切な林道開設量や配置を比較検討し求めてゆくことができる。またその地域の林道密度と平均集材距離の関係が推定できるなど適用の途は広い。

The relation between the length of a forest road construction and the hauling cost, is become clearer by the simulation of a forest road construction using digital terrain map (DTM). It becomes a very useful method to determine the length and arrangement of a forest road, especially in a logging plan of mountain forest. For, it is insufficient to apply the model of a tractor skidding, as Forest Road Density, to the case of a skylinelogging which is a usual logging method in a mountainous region, because the terrain condition often disturbs the setting up there. The hauling cost of a skyline-logging that is determined by some conditions-load, maximum tension, clearance, power of yarder, etc., is calculated by the equation (3) which is a function of the skidding distance and felling volume, using DTM. The value of a forest road construction is calculated by equations (1) and (2). Fig. 2 to Fig. 10 show the application of this simulation method. Talking with a computer about the location, we can determine the suitable forest road network according to the purpose of forest road construction.