@article{oai:iwate-u.repo.nii.ac.jp:00015882,
 author = {渡部, 優 and 斎藤, 仁志 and 白澤, 紘明 and 植木, 達人},
 issue = {1},
 journal = {森林利用学会誌, Journal of The Japan Forest Engineering Society},
 month = {Jan},
 note = {基幹路網整備を加速化させる一方策として，既設路網の高規格化が挙げられるが，高規格化の物理的・経済的な難易は，既設路網の立地と構造の条件によって異なるため，既設路網の高規格化により基幹路網がどの程度整備可能であるかは明らかでない。そこで本研究では，既設路網の高規格化による基幹路網の整備の可能性を，拡幅の観点から明らかにすることを目的とした。長野県伊那市の民有林に整備された作業道，2・3 級林道を対象に，既設路網の全幅員を3.5 m および4.0 m に拡幅するシミュレーションにより，路線ごとに拡幅の物理的可否の判定と拡幅単価の試算を行った。その結果，設定条件下で拡幅可能と判定された路線の総延長が既設低規格路網の総延長に占める割合は，全幅員3.5 m への拡幅の場合は89.0% であり，全幅員4.0 m への拡幅の場合は70.1% であった。路線長の重み付きの平均拡幅単価は全幅員3.5 m への拡幅の場合は1,787 円/m であり，全幅員4.0 m への拡幅の場合は5,537 円/m であった。仮に対象地において，全幅員3.5 m へ拡幅可能なすべての既設路網を拡幅した場合，基幹路網の目標整備水準の達成に必要な整備量の36% を拡幅により賄える可能性が示された。, Upgrading of existing forest roads is a way of accelerating development of high-graded forest roads. However, the difficulty of upgrading in terms of physicality and economic efficiency　differs by conditions of location and structure of existing forest roads. Therefore, it is unclear how amount of development of high-graded forest roads could be achieved by upgrading. The purpose of this study is to clarify the possibility of development of high graded forest roads by upgrading existing forest roads by use of widening simulation. The simulation was performed for forest roads located in private forest of Ina city in Nagano prefecture, and the physical availability and unit cost of widening was resulted. As a result, the ratio of the total length of routes judged to be expandable under the set conditions to the total length of the existing low-standard road network was 89.0% in the case of the expansion to 3.5 m in full width and 70.1% in the case of the expansion to 4.0 m in full width. Average widening unit cost weighted road length is 1,787yen/m in case of widening to 3.5 m full width and 5,537yen/m in case of widening to 4.0 m full width. When all existing forest roads that able to widen to 3.5 m full width on study site, it is revealed that 36% of development amount needed to achieve objective development amount are covered by widening.},
 pages = {17--26},
 title = {既設路網の高規格化による基幹路網の整備の可能性：拡幅シミュレーションによる検討},
 volume = {37},
 year = {2022}
}