The effect of erosion on solute pickup from Mancos Shale hillslopes, Colorado, U.S.A.

Runoff generated directly on Mancos Shale hillslopes initially picks up solutes by surface flushing. The major mechanism of subsequent solute pickup involves transport of soluble minerals as particulate matter with sediment. Solute release increases contemporaneously with increase in sediment concentration during rilling and rill entrenchment. Moreover, solute release increases as the power per unit width of surface area increases, thereby causally explaining the high correlation between runoff salinity and slope inclination. The regression between these two variables may be used as a tool to assess salinity hazard.