Assessing the relationship of slope and runoff volume on skid trails (Case study: Nav 3 district)

Abstract

The effect of slope on runoff volume was evaluated on skid trails in the natural forest in the north of Iran. The objective of this study was to determine the relationship between runoff volume and slope in order to control runoff and skid trail maintenance by using water diversions. Two levels of slope > 20% and < 20% were studied in adjacent parcels in district 3 of Nav in Asalem. Treatment plots with three replications were established on skid trails after skidding and the runoff volume was recorded after duration of 3 rainfalls. The results showed that there was a positive and significant correlation between slope steepness and runoff volume, and between runoff volume and slope length (P < 0.05). Also, regression analysis results showed that there was a linear relation between runoff volume, slope length and slope steepness. Effective recommendations to control and decrease runoff volume are precise scheduling of skid trail designing, construction, maintenance and limiting skid trails to a longitudinal slope of less than 20% and rehabilitation of skid trails by using water diversions.

Keywords

• bulk density
• nav district
• runoff
• skid trail
• water diversion