Abstract
Differential rate of erosion from different slope positions of Palouse region
have changed physical, biological, and hydraulic properties of the soil. The
differences in soil hydraulic properties are believed to control the rate and
movement of infiltrated water which influences the transport of agrochemicals.
Leaching plots were sprayed with bromide at the top-and bottom-slope positions
to assess the impact of slope positions on the vertical and horizontal movement of
a conservative solute. The simulation of computer model (FEMWATER) revealed
that the lateral flow is dominant at the top-slope position indicating low potential
of groundwater contamination. Because of lateral flux at the top-slope position,
significant amounts of bromide had moved about 7 m down-slope outside the
leaching plots. Downward movement at the bottom-slope position, was predomi-
nant which increased the potential of bromide teaching to groundwater.
