Soil Operation, Harvested Volume Changes and Cost of Forest Road and comparing with Standard condition for construction (Case Study: Arzefon District)

Forest road network is the most expensive part of construction, environmentally and economically. For decreasing the environmental and economical bad effects, technical standards for forest road network planning and constructing should be done as a need. In this study, soil volume and costs of the soil operation were investigated along 12.4 Km of second degree Forest Road on Arzefon district in Tajan River Basin and to compare them with standards condition. For this operation slope was classifies into three classes: 0-15, 15-30 and 30 – 45 percent. The length and angle of cutting and filling slopes, width of soil operation were determined by soil texture and slope angles (Based on standards: Guidebook 131 from Budget and Planing Organization). Then operated surface and volume per hectare were calculated using AutoCAD and cross section Profiles were drawn based on three slope classes. Width of clear-cutting and its surface on width of soil operation and volume per hectare were compared with standards. They were analyzed by SPSS and T-student (One sample). Results showed that operated surface from trees for less than 15 percent, 15-30 were 4.49 (ha) and 1.08(ha) respectively and more than standard significantly (1% level). For 30-45 percent class was 0.55 (ha) less than standard and non-significant. Soil operation volume in less than 15 percent was 2.4 times and 15-30 percent was 1.2 times more than standard and 30-45 percent was equal to standard. Along the study Road, adding harvested as volume per hectare was 693 cubic meters more than standard. Finally the cost of soil operation in the study area was calculated 461/700/000 Toman more than standard condition.