The USDA‐ARS Experimental Watershed Network: Evolution, Lessons Learned, Societal Benefits, and Moving Forward

Abstract

The U.S. Department of Agriculture‐Agricultural Research Service's (ARS) Experimental Watershed Network grew from Dust Bowl era efforts of the Soil Conservation Service in the mid‐1930s with the establishment of small experimental watersheds. In the 1950s, five watershed research centers with intensively instrumented watersheds at the scale of 100 to 700 km2 were established. Primary network research objectives were to quantify on‐site and downstream effects of conservation practices and develop rainfall‐runoff relationships for design of water conservation structures. With passage of the Clean Water Act in 1972, research objectives have evolved to add a variety of observations relevant to the water quality issues. Many of the watersheds within the network have served, and continue to serve, as core validation sites for satellite sensors. As a result of the network's long history and intensive monitoring, coupled with mission‐driven research, a deep knowledge base of watershed processes has been developed. This has led to the extensive development and validation of numerous watershed models that are in widespread use today. The visionary investments in building and maintaining this network and associated scientific investigations for more than half a century have not only resulted in numerous high‐impact research accomplishments but also a wide array of accomplishments that directly benefit society. The ARS Experimental Watersheds formed the core of the Conservation Effects Assessment Project (CEAP) as well as the recently established Long‐Term Agroecosystem Research (LTAR) network. LTAR will expand the mission of the ARS Watersheds Network to include agricultural intensification, maintaining or improving ecosystem services while enhancing rural prosperity.

Hydrological modeling using the SWAT Model in urban and peri-urban environments: The case of Kifissos experimental sub-basin (Athens, Greece)

“…Water resource problems, including the effects of urban development, alternative management decisions and future climate oscillation on streamflow and water quality, require a deep understanding and accurate modeling of earth surface processes at the catchment scale in order to be addressed (Gassman et al, 2014). Experimental catchments provide databases of longterm historical hydrological data which are useful in analyzing the mechanisms governing surface runoff as well as for developing and validating watershed, water quality and water resources management models (Goodrich et al, 2020). They are also able to monitor the major components of the surface hydrological cycle by using remote sensing and geophysical measurements (Tauro et al, 2018).…”

“…Bogena et al 2018 presented an extensive overview of hydrological observatories that are presently operated worldwide with various environmental conditions. The US Department of Agriculture-Agricultural Research Service"s (ARS) Experimental Watershed Network has operated over 600 watersheds in its history and currently operates more than 120 experimental hydrological watersheds (Goodrich et al, 2020). The USDA-ARS watersheds provide deep knowledge of watershed processes and contribute in the development and validation of numerous watershed models.…”

The USDA‐Agricultural Research Service's long term agro‐ecosystems Walnut Gulch Experimental Watershed, Arizona, USA

“…The WGEW is operated by the Southwest Watershed Research Center (SWRC) of the U.S. Department of Agriculture (USDA), Agricultural Research Service (ARS) in Tucson and Tombstone, Arizona, USA (https://www.ars.usda.gov/pacific-west-area/tucson-az/southwest-watershed-research-center/) as part of the Long Term Agro‐ecosystem Research (LTAR) network (https://ltar.ars.usda.gov/ —see Goodrich et al, 2021). The 149 km 2 WGEW surrounds the town of Tombstone in southeastern Arizona (Figure 1).…”

“…The WGEW is part of the ARS Experimental Watershed network (Goodrich et al, 2016). Many of the resources to establish and expand this network resulted from nationwide Senate hearings summarized in Senate Document 59 (Senate, 1959).…”

The big picture of field hydrology studies in Brazil

“…hydrological and environmental studies from different countries. Since 1953, the USDA-ARS Experimental Watershed Network has monitored more than 600 basins and currently continues to operate approximately 120 basins, which have been used to develop and validate numerous models (Goodrich et al 2016).…”