Impacts of bioenergy crop cultivation on regional climate, hydrology, and water quality in the U.S. northern high plains

Authors: DANGOL, SIJAL - University Of Maryland; Zhang, Xuesong; SUN, CHAO - University Of Maryland; LIANG, KANG - University Of Maryland; LIANG, XIN-ZHONG - University Of Maryland

Submitted to: Water Resources Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/25/2024
Publication Date: 2/6/2025
Citation: Dangol, S., Zhang, X., Sun, C., Liang, K., Liang, X. 2025. Impacts of bioenergy crop cultivation on regional climate, hydrology, and water quality in the U.S. northern high plains. Water Resources Research. 61(2). Article e2024WR037782. https://doi.org/10.1029/2024WR037782.
DOI: https://doi.org/10.1029/2024WR037782

Interpretive Summary: Understanding the environmental impacts of biofuel cultivation is essential for the design of sustainable bioenergy policies. We used the Climate-Weather Research and Forecasting model to simulate how the cultivation of bioenergy crops on marginal lands in the U.S. can affect regional climate in the contiguous U.S. We then used the Soil and Water Assessment Tool to evaluate responses of the hydrological cycle and water quality to future climate change in the U.S. Northern High Plains. The results show that large-scale cultivation of bioenergy crops on marginal lands could increase precipitation and decrease temperature (i.e., or a wetter and cooler regional climate) in the eastern U.S. Compared with the climate scenario that does not consider climate-crop interactions, the model simulated results show pronouncedly higher streamflow and nitrogen loads from the Northern High Plains for the climate scenario with climate feedback. Our results indicate that growing bioenergy crops can influence both regional climate, hydrology and water quality, which deserve careful assessment to ensure sustainable bioenergy production.

Technical Abstract: The cultivation of bioenergy feedstocks, such as miscanthus, or energycane, on marginal lands helps alleviate the competition between food and fuel. However, such land use conversion could lead to complex interactions among climate, vegetation, and water resources, resulting in positive or negative environmental impacts. In this study, we used the Climate-Weather Research and Forecasting (CWRF) model to simulate the feedback from growing bioenergy feedstock on marginal lands to regional climate for the present and future scenario under the high emission Shared Socioeconomic Pathway (SSP585) and used the Soil and Water Assessment Tool (SWAT) to evaluate the climate change impacts on the hydrological cycle and water quality in the U.S. Northern High Plains Aquifer region. CWRF projected wetter (more precipitation) and cooler (lower temperature) regional climate by considering climate-crop feedback as compared to a control scenario (no land use change and climate feedback), highlighting the importance of land-atmosphere interactions in regional climate assessment. Our watershed scale assessment shows that although growing miscanthus increases local evapotranspiration and decreases surface runoff, soil moisture, and percolation on marginal lands, watershed scale streamflow substantially increases during the growing season in both present and future conditions due to increases in precipitation. The differences in the extent of marginal land use between the Platte (4%) and Republican (20%) river basins result in different responses in streamflow and nitrogen loading. In the future, annual streamflow and nitrogen loading increases by 5.5% and 2.3%, respectively, in the Platte river basin. In contrast, the Republican river basin exhibits negligible changes in annual streamflow and an 8.6% decrease in nitrogen loading. Overall, our study highlights the importance of assessing the regional climate-crop feedback and environmental quality impacts of using marginal lands for future sustainable bioenergy production.