Water Resources Research Act Program

Details for Project ID 2019WI001S

Mapping Annual Irrigated Lands in the U.S. to Support Irrigation Water-Use Estimation

Institute: Wisconsin
USGS Grant Number: G19AC00080
Year Established: 2019 Start Date: 2019-04-01 End Date: 2020-09-30
Total Federal Funds: $140,822 Total Non-Federal Funds: Not available

Principal Investigators: James Hurley

Project Summary: Improved nationwide understanding of the spatial and temporal trends in irrigated land use is urgently needed to improve assessment and monitoring of water resources and help navigate rising challenges related to regional water scarcity, increasing demands for agricultural production, and environmental sustainability. Agriculture currently accounts for over 80 percent of consumptive water use in the U.S., and irrigation used for crop production continues to expand in select regions, including some that depend on minimally renewable groundwater resources (USDA, 2016; Brown and Pervez, 2014). Total U.S. cropland area, including rainfed and irrigated fields, has also recently increased (Lark et al., 2015) and further expansion is likely to occur in response to future demands (Alexandratos et al., 2012; Valin et al., 2014). As increases in weather variability and the frequency of events like droughts add pressure on water resources (Elliott et al., 2014), finding solutions to sustainably and reliably produce food, feed, fiber, and fuel amid limited freshwater availability becomes even more pressing.Despite the critical nature of these issues, substantial gaps in our understanding of irrigated agriculture and crop water use remain. Although various efforts have worked to map the nationwide distribution of irrigated croplands, the existing products suffer from low spatial resolution and accuracy as well as limited temporal coverage and frequency. These shortcomings in irrigation mapping hinder efforts to accurately and precisely estimate agricultural water use. To address these gaps, researchers at the University of Wisconsin-Madison (UW) in close collaboration with the USGS will generate new field-level (30-meter) nationwide datasets of irrigated cropland locations across the U.S. for the time period of 1997-2017. These maps will provide data at higher spatial and temporal resolution than current products and help support data-driven science and assessments of irrigation dynamics and agricultural water use.