Regional Scale Characterzation and Assessment of Water Use and Competition Impacts for U.S. Food Crops

Abstract

Our growing population and increasingly variable climate conditions challenge our ability to meet pressing demands for food, water and energy. With approximately 70% of U.S. freshwater resources applied to agriculture with most withdrawals occurring in water scarce regions, critical analysis is required to determine how regional water use and availability impact user competition for water resources. Aiming to provide insight into the cradle-to-farm gate impacts of different U.S. consumed crops, this thesis begins with a comprehensive literature review to consider the progress and opportunities occurring around water scarcity studies over the last 40 years. Using empirical data and emerging water impact assessment models, a methodology is proposed providing characterization of 10 U.S. consumed crops at regional levels (county, state, and national), resulting in production-weighted water competition footprints for each crop. This analysis also considers water competition footprints of crop imports and exports, which factor into national water footprint values of U.S. consumed crops. Results contrast water use and competition footprint values for select crops at difference spatial scales, indicating the significant impact agricultural processes have in water scarce regions. This research is expected to contribute towards diet-level impact studies, filling gaps where additional life cycle water assessment methods are needed.