Construction of Critical Periods for Water Resources Management and Their Application in the FEW Nexus

Val Z Schull,Shweta Singh,Juan P Sesmero,Margaret W Gitau,Dennis C Flanagan,Sushant Mehan,David R Johnson

doi:10.3390/w13050718

Val Z Schull, Shweta Singh + Show 5 more

Open Access

https://doi.org/10.3390/w13050718

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Abstract

Amidst the growing population, urbanization, globalization, and economic growth, along with the impacts of climate change, decision-makers, stakeholders, and researchers need tools for better assessment and communication of the highly interconnected food–energy–water (FEW) nexus. This study aimed to identify critical periods for water resources management for robust decision-making for water resources management at the nexus. Using a 4610 ha agricultural watershed as a pilot site, historical data (2006–2012), scientific literature values, and SWAT model simulations were utilized to map out critical periods throughout the growing season of corn and soybeans. The results indicate that soil water deficits are primarily seen in June and July, with average deficits and surpluses ranging from −134.7 to +145.3 mm during the study period. Corresponding water quality impacts include average monthly surface nitrate-N, subsurface nitrate-N, and soluble phosphorus losses of up to 0.026, 0.26, and 0.0013 kg/ha, respectively, over the growing season. Estimated fuel requirements for the agricultural practices ranged from 24.7 to 170.3 L/ha, while estimated carbon emissions ranged from 0.3 to 2.7 kg CO2/L. A composite look at all the FEW nexus elements showed that critical periods for water management in the study watershed occurred in the early and late season—primarily related to water quality—and mid-season, related to water quantity. This suggests the need to adapt agricultural and other management practices across the growing season in line with the respective water management needs. The FEW nexus assessment methodologies developed in this study provide a framework in which spatial, temporal, and literature data can be implemented for improved water resources management in other areas.

Highlights

With a changing climate, rapid population growth, and urbanization, robust and innovative solutions are needed to address the increasing and competing needs for food, energy, and water
Due to the major role that water quality and quantity play in the FEW nexus, constructing critical periods for water management is important
The amount of water required by crops varied through the season, with needs for corn and soybeans being greatest during the summer months

Summary

Introduction

Water resource allocation and water quality are especially critical within the FEW nexus framework, as clean water is required for both food and energy production [2,3,4], yet both food and energy production have negative impacts on water quality [5]. Adverse impacts on water quality, in turn, have implications on the amount of water available for anthropogenic and ecosystem allocations. Both aspects of water resources integrity (quantity and quality) need to be considered in FEW nexus assessments so as to avoid misconceptions related to the availability of water resources. B.T.; Mohtar, R.H. Water–energy–food (WEF) Nexus Tool 2.0: Guiding integrative resource planning and decision-making

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