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Submitted to: Book Chapter
Publication Type: Book / Chapter Publication Acceptance Date: 12/12/2006 Publication Date: 7/1/2007 Citation: Nichols, M.H. 2007. The walnut gulch experimental watershed - 50 years of watershed monitoring and research. In: Monitoring and Evaluation of Soil Conservation and Watershed Development Projects. de Graaff, J, Cameron, J., Sombatpanit, S., Pieri, C., Woodhill, J.(eds.). World Association of Soil and Water Conservation, Bangkok. 496 p. Interpretive Summary: The USDA - Agricultural Research Service - Walnut Gulch Experimental Watershed was established in 1953 to study floods and the impact of soil and water conservation projects on runoff. The 150 sq. km. watershed was instrumented with raingages and runoff measuring flumes, and to date, 50 years of data have been collected. These data have been analyzed to characterize precipitation in convective thunderstorms and to study and model subsequent flood wave movement, transmission losses, and water yield from rangeland watersheds. The effects of topography and various soil, vegetation, and surface cover complexes on water and sediment movements have been studied on individual plots and over watersheds. The initial research objectives have expanded to include remote sensing, nutrient cycling, and development of decision support systems. This chapter focuses on hydrologic and erosion research and includes a description of instrumentation and monitoring sites, a description of major research findings, and a summary of lessons learned from measurement and field experiences associated with both long-term and short-term projects. Research at the Walnut Gulch Experimental Watershed continues to impact national and international soil and water conservation efforts. Technical Abstract: The USDA - Agricultural Research Service - Walnut Gulch Experimental Watershed was established in 1953 with the broad objectives to 1) determine the effects of conservation projects on water yield and sediment movement and 2) quantify flood runoff from semiarid rangeland watersheds. The 150 sq. km. watershed was instrumented with raingages and runoff measuring flumes arranged in a pattern of nested sub-watersheds. Data collected during the past 50 years have been analyzed to characterize precipitation in convective thunderstorm dominated regions and to study and model subsequent flood wave movement, transmission losses, and water yield from complex watersheds. The effects of topography and various soil, vegetation, and surface cover complexes on water and sediment movements have been studied at spatial scales ranging from plots to watersheds. The initial research objectives have expanded to include remote sensing, nutrient cycling, and development of decision support systems. The comprehensive database has been used to characterize baseline conditions and variability inherent in semiarid rainfall and runoff. The data have also been used to develop rainfall, runoff, and erosion prediction technologies. This chapter focuses on hydrologic and erosion research and includes a description of instrumentation and monitoring sites, a description of major research findings, and a summary of lessons learned from measurement and field experiences associated with both long-term and short-term projects. |
