Trends in Water Use, Energy Consumption, and Carbon Emissions from Irrigation: Role of Shifting Technologies and Energy Sources

Abstract

Novel low-pressure irrigation technologies have been widely adopted by farmers, allowing both reduced water and energy use. However, little is known about how the transition from legacy technologies affected water and energy use at the aquifer scale. Here, we examine the widespread adoption of low-energy precision application (LEPA) and related technologies across the Kansas High Plains Aquifer. We combine direct energy consumption and carbon emission estimates with life cycle assessment to calculate the energy and greenhouse gas (GHG) footprints of irrigation. We integrate detailed water use, irrigation type, and pump energy source data with aquifer water level and groundwater chemistry information to produce annual estimates of energy use and carbon emissions from 1994 to 2016. The rapid adoption of LEPA technologies did not slow pumping, but it reduced energy use by 19.2% and GHG emissions by 15.2%. Nevertheless, water level declines have offset energy efficiency gains because of LEPA adoption. Deeper water tables quadrupled the proportion of GHG emissions resulting from direct carbon emissions, offsetting the decarbonization of the regional electrical grid. We show that low-pressure irrigation technology adoption, absent policies that incentivize or mandate reduced water use, ultimately increases the energy and carbon footprints of irrigated agriculture.

Combining Remote Sensing and Crop Models to Assess the Sustainability of Stakeholder‐Driven Groundwater Management in the US High Plains Aquifer

“…We then translated the volume of water extracted into required energy to operate groundwater pumps based on estimates from McCarthy et al. (2020). Briefly, their method calculated energy use annually for each well in the WIMAS database based on three quantities: (1) annual water volume extracted; (2) annual depth to water derived from groundwater level maps and estimates of each well's cone of depression from aquifer saturated thickness and hydraulic conductivity; and (3) energy efficiencies based on each well's pump type and energy source.…”

“…To estimate monetary savings from reduced pumping costs, we first quantified the pumping volumes for the BAU and LEMA models for 2013-2017. We then translated the volume of water extracted into required energy to operate groundwater pumps based on estimates from McCarthy et al (2020). Briefly, their method calculated energy use annually for each well in the WIMAS database based on three quantities: (1) annual water volume extracted;…”

Adapting agriculture to climate change via sustainable irrigation: biophysical potentials and feedbacks

“…Additional energy and greenhouse gas emissions from irrigation expansion will come from the production of machineries and infrastructure required to industrialize agriculture from rainfed to irrigated systems [178]. While a shift to more efficient irrigation technologies can reduce energy and greenhouse gas emissions due to lower pumping of water, declines in water levels and deeper groundwater levels in water scarce regions can offset energy efficiency gains from efficient irrigation technologies [184]. Solar powered drip irrigation systems are a cost-effective solution promoted by the United Nations to reduce dependence on fossil fuels-based irrigation and reliance on international markets for energy import [105,185].…”

Landsat-based Irrigation Dataset (LANID): 30 m resolution maps of irrigation distribution, frequency, and change for the US, 1997–2017

“…For example, state-level water managers and engineers who need to plan how much water to allocate for agriculture could utilize our irrigation distribution and change information to estimate demand. Policy makers may also use LANID to navigate future decision making and to evaluate federal agricultural, bioenergy, and conservation policies (Mccarthy et al, 2020;Lark, 2020).…”