Most freshwater withdrawn from lakes and underground aquifers in the United States is used for irrigation, a technology which has greatly enhanced food security and biofuel production. Increased demand for water paired with water depletion and pollution has challenged the sustainability of irrigation, and it is important to have a comprehensive understanding of agricultural withdrawal across the contiguous US to continue irrigating. A new study, published in Environmental Research Letters and partially funded by the Climate Program Office’s Climate Observations and Monitoring (COM) Program, investigates the spatial patterns of water withdrawal across the country from 1981 to 2015. Ruijie Zeng and Weiwei Ren of Arizona State University used nationally-scaled climate and agriculture datasets to investigate where, when, and how trends occurred, focusing on an eastward expansion of withdrawal activities through time. These results provide a large-scale understanding of the driving forces of agricultural withdrawal under changing climatic and socioeconomic uncertainties, enhancing predictability of these trends. This study contributes to efforts by the COM program to use existing long-term observations to improve projections and resource management.
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