Erosion processes on arid minespoil slopes

Surface wash and dry ravel erosion rates from minespoil were measured for 4.7 yr after initial reclamation at a site in western Nevada. Neither mulching treatment nor slope gradient (3:1 vs. 2:1) significantly affected surface wash from reclaimed minespoils. About 70% of the total wash load from the entire study period occurred during two midsummer to autumn periods (1989 and 1990) in which the most intense storms occurred. The higher surface roughness encountered on 2:1 slopes appeared to more effectively control surface wash. Straw mulch significantly reduced ravel erosion from the relatively smooth 3:1 slopes. Ravel rates were not as directly affected by rainfall intensity as were surface wash rates. Except for very dry collection periods (including autumn to spring), surface wash exceeded ravel. -from Author