Proper designing of the geometric specification of forest roads has an effective role in reducing sediment produced from the cut slope. Given the importance of this study, the researchers investigated the role of the LS factor on the rate of soil loss after constructing forest road in the Pashakola forest, Iran.
In this study, the rate of soil loss were measured at 180 profiles. Rubbers with dimensions 1.5 × 1 m were mounted beneath the cutslope and above the ditch to measure the rate of soil loss after the first precipitation. Inclinometer and laser rangefinder were used to measure the slope and length of cutslope, respectively.
With an increase in cut slope gradient, there was increasing rate of soil loss. Thus, there was a significant linear relationship with equation of Y=0.23 ln (x)- 0.242 between cut slope gradient and soil loss rate (R2 = 0.69, P>0.05). Subsequently, with increased cut slope length there was also an increasing rate of soil loss,. Thus, there was a significant linear relationship with equation of Y= 0.142x + 0.858 between cut slope length and soil loss rate (R2 = 0.71, P>0.05).
The bioengineering techniques and construction materials were used to control and consolidate soil on cut and fill slopes. Seed spraying, seed planting and soil consolidation using Gabion and wooden walls were some of the bioengineering techniques that can be used to reduce soil loss.
Keywords: Soil loss, Forest road construction, LS factor, Bioengineering