Climatic influences on Holocene variations in soil erosion rates on a small hill in the Mojave Desert

A study of a small hill in NE Mojave Desert in eastern California was conducted to determine the effect of climate on variations in soil erosion rates in the Holocene. Field surveys and sampling obtained information on topography, geomorpohology, soil and vegetation conditions, seismic refraction, sediment deposition, and hillslope processes. The hill topography at the end of the Holocene was reconstructed, and the evolution from the end of the Holocene to the present was deduced. Holocene transport rates were estimated. Packrat midden studies by other investigators imply that the NE Mojave Desert experienced enhanced monsoonal precipitation in the early Holocene, presumably accentuating soil loss. Water erosion on one slope of the hill was simulated using WEPP (Water Erosion Prediction Project) using 4 kyr and 6 kyr of precipitation input compatible with an appropriate monsoonal climate and the present climate, respectively. The WEPP-predicted soil losses for the chosen slope were compatible with inferred soil losses. Identification of two time periods within the Holocene with distince erosion characteristics may provide new insight into the current state of Mojave Desert landform evolution.