Erosion control practices applied to granitic roadfills for forest roads in Idaho: Cost effectiveness evaluation

摘要

AbstractCost effectiveness of six alternative road embankment construction practices and 16 alternative fill‐slope stabilization practices was evaluated as means for controlling erosion on forest roads built on granitic soils in Idaho (USA). A total of 63 bordered erosion plots 1‐8 m wide by 4‐6 m long, were used. Eroded material was collected in troughs at the bottom of each plot in the spring and fall. Measurements began in the fall of 1981 and continued until the fall of 1983. Costs were obtained by tabulating actual labor, equipment, and supplies used to install the treatments. Rainfall erosivity values accumulated for the snow‐free periods between erosion measurements proved to be a statistically significant covariate for the analysis of treatment effects. There were no significant differences between the three embankment construction practices (sidecast, layer placed, and controlled compaction). But surface rolling did significantly increase erosion in all cases. Nine of the post‐construction soil stabilization measures significantly reduced erosion, and one measure significantly increased erosion (P<0‐5). Stabilization measures that combined mulches with revegetation appeared to be more beneficial for erosion control than either mulches or revegetation alone. Rankings of the erosion control effectiveness of individual soil stabilization practices were different from the rankings of the cost effectiveness of the practices. Application of alternative treatments i