2011 Annual Report
Parameter estimation equations for concentrated flow hydraulic friction factors and flow width, based on extensive datasets of overland flow and erosion experiments from disturbed rangeland conditions across the Great Basin, were implemented in the Rangeland Hydrology and Erosion Model (RHEM). These parameter estimation procedures will soon undergo testing and review at independent disturbed rangeland sites across the west. Using the same extensive database, work was initiated to develop estimation procedures for concentrated flow erodibility parameters for disturbed rangeland conditions. ARS scientists at the Northwest Watershed Research Center in Boise, Idaho worked closely with ARS scientists from the Southwest Watershed Research Center in Tucson, Arizona on efforts to improve estimates of runoff contributions from snowmelt in the Automated Geospatial Watershed Assessment (AGWA) tool were initiated. Scripts to take outputs from a detailed physically-based snow accumulation and melt model (ISNOBAL) and provide them as input to AGWA are nearly finalized. This will provide the means to test the level of detailed snow information needed to improve large-scale runoff estimates from snow-dominated landscapes using AGWA. Research progress and status are reported via bi-monthly project teleconference calls, frequent email and onsite visits. This agreement was established in support of Objective 1 and 2 (Sub-Objective 2.B) of the in-house project, the goals being to develop strategic management tools and guidelines for use in fire impact assessment and rehabilitation planning of sagebrush ecosystems of the Intermountain West to aid land managers in determining the location, severity and persistence of fire impacts on post-fire runoff/erosion; and to improve assessments of juniper impacts on runoff and erosion processes by enhancing infiltration and erosion parameter estimations for RHEM.