Analyzing FEW Nexus modeling tools for water resources decision-making and management applications

Authors: SCHULL, VAL - Purdue University; DAHER, BASSEL - Texas A&M University; GITAU, MARGARET - Purdue University; MEHAN, SUSHANT - Formation Environmental Llc; Flanagan, Dennis

Submitted to: Food and Bioproducts Processing
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/18/2019
Publication Date: 10/31/2019
Citation: Schull, V.Z., Daher, B.T., Gitau, M.W., Mehan, S., Flanagan, D.C. 2019. Analyzing FEW Nexus modeling tools for water resources decision-making and management applications. Food and Bioproducts Processing. 119:108-124. https://doi.org/10.1016/j.fbp.2019.10.011.
DOI: https://doi.org/10.1016/j.fbp.2019.10.011

Interpretive Summary: Resources related to food production, water quantity/quality, and energy supplies are very interrelated. This is known as the Food-Energy-Water (FEW) nexus. Substantial amounts of water are needed for crop production, as well as fuel to power tillage, planting, harvesting, irrigation, and other field operations. Energy production can utilize large amounts of water, and impact water quality. Recently, new types of computer simulation models have been developed that allow examination of these interrelated resources, and how external factors such as climate change may affect energy and water demands during crop production, as well as carbon emissions and water quality. In this paper, several different FEW nexus modeling tools were evaluated, and one was selected that was best adapted to application in the Midwest U.S. (WEF Nexus Tool 2.0). This tool was applied in a case study to an agricultural watershed in DeKalb County in northeastern Indiana, along with the Soil and Water Assessment Tool (SWAT) model, to examine how possible changes in future climate (rainfall, temperatures) may affect crop yields, water needs, energy usage, and water quality in the stream. We found that the combination of these tools was useful and provided information on projected climate change impacts on surface water quality that were similar to those found in previous studies for this watershed. Additionally, the tools provided information on water usage, energy usage, crop yields, and carbon dioxide emissions from the field operations and fertilizer production. This research impacts scientists, faculty, students, and others with an interest in understanding the effects of various cropping/management rotations, fertilizer sources, water sources, energy sources and other factors (climate change, etc.) on energy use, water use, food production, carbon emissions, and water quality. Some of the novel techniques explored in this study may be particularly useful in future comprehensive FEW nexus analyses.

Technical Abstract: Social changes such as growing population, urbanization, globalization, and economic growth, compounded with uncertainties due to climate change are expected to result in substantial shifts in the demand for food, energy, and water. Food, energy and water resource systems are tightly interconnected. Addressing challenges facing any of these resource systems requires a holistic understanding and quantification of the existing interdependencies and trade-off. This study is aimed at analyzing FEW nexus modeling tools with a specific focus on addressing issues of water management through a nexus lens. In particular, an exploratory approach is taken to assess available FEW nexus modeling tools to determine their accessibility, knowledge gaps, and potential for including aspects that provide better insight into the nexus such as water quality, futuristic scenarios due to climate change, and varying scales within the nexus. A case study in an agricultural watershed in northeastern Indiana is presented which builds on the WEF Nexus Tool 2.0 framework and assessment criteria. From this case study, the implementation of spatial and temporal analysis through SWAT was implemented. This provided a water quality component to the framework enabling a more representative analysis of the FEW nexus.