KINEROS2 model was applied to simulate watershed erosion in Barry M Golden Range (BMGR) – West in Yuma, Arizona. The range is approximately 1000-square-mile, and land cover is primarily shrub/scrub and barren land. It consists of three major watersheds: Yuma Desert Wash, Coyote Wash and Mohawk Wash. If using the default parameters in KINEROS2, none of the simulated erosion depth in the sub-basins matched the observations. The average simulated erosion depth are two orders of magnitude smaller than the observations. Therefore, a stepwise secant method was used to calibrate the key modeling parameters including saturated hydraulic conductivity, Manning’s roughness, mean capillary drive, rainsplash coefficient and cohesion coefficient. The calibrated results yielded only 11%, 30% and 36% sub-basins matched the observations satisfactorily in Yuma Desert Wash, Coyote Wash and Mohawk Wash, respectively. Results in the majority of sub-basins were still smaller than the observations even though the parameters that could yield the maximum erosion were used. This indicates the limited capability of KINEROS2 in simulating watersheds in arid and semi-arid region.
Kang Zhou– RA, University of Arizona, Tucson, Arizona