Observations of irrigated agricultural land within the San Simon Valley Groundwater Subbasin of the Safford Groundwater Basin. Digitized field boundaries were used to locate crops for in situ verification twice in 2022; crop verification occurred first on May 18th and again on August 24th. Field boundaries were digitized from U.S. Department of Agriculture, National Agricultural Imagery Program County Mosaic 2021 imagery for Arizona and supplemented with Landsat and Sentinel2 imagery collections accessed via the Sentinel Hub, Sentinel Playground (https://apps.sentinel-hub.com/sentinel-playground). Satellite images were also used to identify the length of the growing season and crop condition. Water withdrawals were calculated using the modified Blaney-Criddle model of calculating consumptive use (U.S. Bureau of Reclamation, 1992 appendix A) using crop coefficients from Doorenbos and Pruitt (1975), the number of acres with active crops, crop condition, and irrigation system efficiency. The withdrawal equation was modified from "Water withdrawals for irrigation, municipal, mining, thermoelectric-power, and drainage uses in Arizona outside of active management areas, 1991-2000" (Tadayon, 2005) to account for variations in water application.
Data are available as a shapefile for visualization or as a stand-alone csv table for attributes only.
Bureau of Reclamation, 1992, Plan of study and methods manual for Colorado River system consumptive uses and losses report 1985–1990: Bureau of Reclamation, Appendix A, 23 p.
Doorenbos, J. and Pruitt, W.O.,1975, Guidelines for predicting crop water requirements: Irrigation and drainage paper FAO No. 24, p195, https://www.nrc.gov/docs/ML1821/ML18215A282.pdf.
Tadayon, Saeid, 2005, Water withdrawals for irrigation, municipal, mining, thermoelectric-power, and drainage uses in Arizona outside of Active Management Areas, 1991–2000: U.S. Geological Survey Scientific Investigations Report 2004-5293, 28 p.
