Estimated crop irrigation water use withdrawals in Ranegras Plain Groundwater Basin, Arizona for 2021

Observations of irrigated agricultural land within the Ranegras Plain Groundwater Basin in Arizona. Crops were verified in situ twice in 2021, first on May 19th and again on September 1st; based on digitized field boundaries. Field boundaries were digitized from U.S. Department of Agriculture, National Agricultural Imagery Program images dated 2021 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.