Erosion and sedimentation research is conducted at the Southwest Watershed Research Center to: Determine upland and channel erosion and sedimentation processes and their impact on water quality, semiarid landscape evolution and the health and sustainability of rangeland ecosystems Develop new technology to determine the rate of soil loss an ecosystem can endure and still remain economically and ecologically sustainable

Suggested publication:

Lane, L. J., Hernandez, M., Nichols, M. H. Processes Controlling Sediment Yield from Watersheds as Functions of Spatial Scale. Journal of Environmental Modelling & Software, Vol. 12, No. 4, 1997, pp. 355-369. Published 1997.

Rainfall simulation is a valuable tool for evaluating the hydrologic and erosional responses of the natural environment and provides researchers maximum control over where, when, and how data are collected. Rainfall simulation has been conducted since 1981 on the Walnut Gulch Experimental Watershed to quantify erosion prediction model parameters for rangeland conditions under various soil/vegetation complexes.

Studies are conducted using a rotating boom rainfall simulator on 10.7 by 3.05 m (35 x 10 ft) plots. The simulator applies rainfall intensities of about 65, 130, or 90 mm/hr (2.5, 5, 7.5 in/hr). Changes in rainfall intensities are produced by increasing or decreasing the number of open nozzles. Because of the simple design and portability of the simulator and because two plots are covered during one run, many plots can be evaluated in a relatively short time.

	18 stock ponds on the Walnut Gulch Watershed capture runoff and sediment. Runoff into 10 of the ponds is currently being monitored with water level recorders, and periodic surveys are conducted to compute sediment yield rates.