The spatiotemporal trajectory of US agricultural irrigation withdrawal during 1981–2015

Abstract

Irrigation has enhanced food security and biofuel production throughout the world. However, the sustainability of irrigation faces challenges from climate variability and extremes, increasing consumption from irrigated cropland expansion, and competing demands from other water use sectors. In this study, we investigated the agricultural water withdrawal landscape of the contiguous US (CONUS) over 1981-2015, assessed its spatial and temporal changes and analyzed the factors driving the changes. We introduced the concept of “center of mass” to calculate the spatiotemporal trajectory of water withdrawal, along with climatic and agricultural factors at state, regional and CONUS scales. At the CONUS level, the total agricultural water withdrawal has decreased during 1981-2015, and the centroid of water withdrawal consistently moved toward the east, caused by reduced water withdrawal in the western states and increased withdrawal in the eastern states. While the CONUS irrigation trajectory was resilient to climate variability, prolonged regional drought may interrupt the trend. In the Western US, irrigation withdrawal reduction was mainly achieved by adoption of high-efficiency irrigation technology. Under drought conditions, irrigation withdrawal often switched from surface water to groundwater sources, posing challenges on groundwater sustainability under prolonged drought conditions. The Eastern US has experienced accelerating agricultural withdrawal from both surface water and groundwater sources. This was mainly driven by increased irrigated acreage in the Midwest and lower Mississippi River, with irrigated croplands supplied by mixed flood irrigation and high-efficiency irrigation methods. At the state level, some states exhibited discrepancy in agricultural withdrawal centroids from surface water and groundwater sources, as results of climate heterogeneity, water availability and infrastructure development. This study provides understanding of the driving forces in the spatiotemporal trends of CONUS agricultural water withdrawal in different regions and implications for predicting future agricultural withdrawal under changing climatic and socioeconomic uncertainties.

Temporal and Spatial Pattern Change in Evapotranspiration Over the High Plains: The Impact of and Guide on Extensive Groundwater‐Fed Irrigation

“…The regulation changes have limited the groundwater pumping for irrigation, prevented water depletion, and restored the streamflow to some extent (Smith et al., 2011). The USGS water use reports also shows that agricultural withdrawals in this region have peaked and started to decrease in recent years (Zeng & Ren, 2022).…”

Comment on essd-2024-2

“…The trends were quantified by calculating the slope of the regression line fitted to the time-series data of irrigated areas at the pixel scale using the least squares method. Furthermore, we adopted the concept of "center of gravity" to track the spatial dynamics of irrigated areas (Zeng and Ren, 2022). The gravity center of irrigated area (X, Y) is represented as: where 𝐼𝑟𝑟𝐴𝑟𝑒𝑎 𝑖 𝑡 denotes the irrigated area in grid i; xi and yi are the longitude and latitude of grid i, respectively; n is the number of irrigated cropland grids; and t is year.…”

Comparison of Machine Learning Models in Simulating Glacier Mass Balance: Insights from Maritime and Continental Glaciers in High Mountain Asia

“…Moreover, it is important to note that the dynamics of glacier mass balance (GMB) modelling are intricately linked to climate changes, influencing both the timing and magnitude of transitions in hydrological regimes [6]. Therefore, accurate GMB modeling is imperative in order to assess the impact of climate change on glaciers and provides a vital foundation for elucidating glacier dynamic processes, predicting changes, and effectively managing basin water resources [7][8][9].…”