Southwest Watershed Research : Erosion and Sedimentation

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.

Rainstorm on the Walnut Gulch Experimental Range