Estimated crop irrigation water use withdrawals in Hualapai Valley Groundwater Basin, Arizona for 2014-2018

Observations of irrigated agricultural land within the Hualapai Valley Groundwater Basin in Arizona. Crops were estimated via satellite imagery or verified in situ for 2014-2018, based on digitized field boundaries. Field boundaries were digitized from U.S. Department of Agriculture, National Agricultural Imagery Program images dated 2015 and 2017 as well as the Landsat and Sentinel2 imagery collections accessed via the U.S. Geological Survey LandsatLook Viewer (https://landlook.usgs.gov/landlook/). Satellite images were also used to observe crop type, crop growing season, crop condition, and irrigation system characteristics. 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.