The USDA-Agricultural Research Service's Long Term Agro-ecosystems Walnut Gulch Experimental Watershed (WGEW), Arizona, USA

Authors: Goodrich, David - Dave; Heilman, Philip - Phil; Nearing, Mark; Nichols, Mary; Scott, Russell - Russ; Williams, Christopher - Jason; Biederman, Joel

Submitted to: Hydrological Processes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/1/2021
Publication Date: 8/11/2021
Citation: Goodrich, D.C., Heilman, P., Nearing, M.A., Nichols, M.H., Scott, R.L., Williams, C.J., Biederman, J.A. 2021. The USDA-Agricultural Research Service's Long Term Agro-ecosystems Walnut Gulch Experimental Watershed (WGEW), Arizona, USA. Hydrological Processes. 35, Article 14349. https://doi.org/10.1002/hyp.14349.
DOI: https://doi.org/10.1002/hyp.14349

Interpretive Summary: Experimental watersheds have been a major avenue to gain an understanding of watershed hydrology and processes. This presentation provides background and overview of the Walnut Gulch Experimental Watershed (WGEW). It is operated by the Southwest Watershed Research Center of the U.S. Department of Agriculture (USDA), Agricultural Research Service (ARS) in Tucson/Tombstone, Arizona, USA. It is perhaps the premier semiarid research watershed in the world. The ephemeral 149 km2 WGEW surrounds the town of Tombstone, in southeastern Arizona. It is representative of roughly 60 million hectares of grass and brush covered rangeland found throughout the semiarid southwest and northern Mexico. The WGEW is part of the larger ARS Experimental Watershed network. Initial instrumentation efforts of the WGEW began in 1953 and were directed toward collecting precipitation and flood hydrology data. A basic premise for driving the early research on the WGEW and other ARS Experiment Watersheds around the country was to build on a continuous long-term core data collection network with the flexibility to address contemporary watershed issues through an evolving research program. The pressing watershed issue at that time was understanding the effects of soil and water conservation practices on water and on downstream water users. The network of rain gauges, flumes, and weirs was largely finished by 1964, consisting of 85 recording rain gauges (recently expanded to 103) and 22 nested watersheds creating one of the densest rain gauge and runoff networks in the world for drainages over 50 km2. The current configuration of instrumentation and observations on the WGEW are described as well where to obtain the watershed data.

Technical Abstract: Experimental watersheds have been a major avenue to gain an understanding of watershed hydrology and processes. This presentation provides background and overview of the Walnut Gulch Experimental Watershed (WGEW). It is operated by the Southwest Watershed Research Center of the U.S. Department of Agriculture (USDA), Agricultural Research Service (ARS) in Tucson/Tombstone, Arizona, USA. It is perhaps the premier semiarid research watershed in the world. The ephemeral 149 km2 WGEW surrounds the town of Tombstone, in southeastern Arizona. It is representative of roughly 60 million hectares of grass and brush covered rangeland found throughout the semiarid southwest and northern Mexico. The WGEW is part of the larger ARS Experimental Watershed network. Initial instrumentation efforts of the WGEW began in 1953 and were directed toward collecting precipitation and flood hydrology data. A basic premise for driving the early research on the WGEW and other ARS Experiment Watersheds around the country was to build on a continuous long-term core data collection network with the flexibility to address contemporary watershed issues through an evolving research program. The pressing watershed issue at that time was understanding the effects of soil and water conservation practices on water and on downstream water users. The network of rain gauges, flumes, and weirs was largely finished by 1964, consisting of 85 recording rain gauges (recently expanded to 103) and 22 nested watersheds creating one of the densest rain gauge and runoff networks in the world for drainages over 50 km2. The current configuration of instrumentation and observations on the WGEW are described as well where to obtain the watershed data.