| Gary W. Frasier, Mark Weltz, and Laura Weltz |
| Authors are Research Hydraulic Engineer, USDA-ARS, Rangeland Resources Research, 1701 Center Ave. Fort Collins, Colo. 80526, Hydrologist-Research Leader, USDA-ARS, Southwest Watershed Research Center, 2000 East Allen Road, Tucson, Ariz. 85719 and Consultant, 4810 N. Desert Tortoise Pl., Tucson, Ariz. 85745, formerly Research Assistant, Colorado State University, Fort Collins, Colo. 80523. |
Abstract |
| Rainfall simulators have been used more than 50 years to evaluate hydrologic parameters. The generated runoff hydrograph is a continuous integration of all factors that affect runoff flow. The complexity and interaction of site factors on runoff and infiltration processes makes it difficult to identify a single component of the hydrograph that accurately characterizes the entire runoff event. A technique was developed to separate the runoff hydrograph into segments representative of different portions of the flow event. Each segment grouping is analyzed for treatment and/or site factor differences or influences on the runoff. Comparing the treatment or site impacts on each hydrograph component allows a more detailed interpretation of the runoff and infiltration processes. This approach to runoff hydrograph analysis makes it possible to quantitatively assess differences in rainfall simulator runoff results and provide insight into why hydrographs may be similar or different. |
| Key Words: rangeland, hydrology, runoff/infiltration, simulation |