Climatic and Anthropogenic Influences on Food and Water Security

Ensuring food security for the growing global population is one of the pressing challenges of the 21st century. The interconnectedness of food and water systems necessitates an integrated assessment of food security in conjunction with water security. This dissertation focuses on food and water systems and their interaction with climate and anthropogenic factors. Specifically, it has the following research objectives: (1) to quantify the sensitivity of crop yields to droughts for major crops and investigate the association of various climate and anthropogenic factors on the change in crop yield loss risk, (2) to elucidate the potential controlling drivers and their influence on contrasting corn acreage trends between Midwestern and Southeastern United States, (3) understand and quantify the unsustainable virtual water flows inherent in crop trade, and (4) to assess the impact of anthropogenic influences such as irrigation expansion and reservoir operations on water scarcity. To address the outlined objectives, a range of statistical and process-based modeling and data analytics are utilized. The first objective is achieved by developing a copula-based drought yield loss risk index for crop-producing counties. The results indicate that, historically, the growing-season droughts have become drier in only 52% of the county growing period instances over the cropped regions of the US. Additionally, crop risks from droughts vary significantly both spatially and temporally. Only about 55% of the sites experiencing drier droughts have seen an increase in yield risk from these droughts. Ancillary climatic variables, such as kill degree days and vapor pressure deficit, as well as anthropogenic factors, such as fertilizer application, significantly mediate the changes in yield risks under drier drought conditions. These findings challenge the notion that droughts are uniformly becoming drier in crop-growing regions over time and that more intense droughts will necessarily lead to increased crop yield risks. For the second objective, historical profit from corn farming per acre between Midwestern and Southeastern US was intercompared. Findings indicate that both hydroclimatology and anthropogenic interventions, such as irrigation expansion, can have a significant influence on crop acreage dynamics. Furthermore, economic incentives for farmers to expand irrigation can potentially stem crop acreage losses. To address the third objective, a virtual water flow sustainability assessment is performed by leveraging food trade and water footprint datasets. The findings identify that one-third of the virtual water flow in the United States due to cereal and milled grain trade is unsustainable as it originates from water-scarce regions. The fourth objective involves using a process-based hydrological model to develop a water demand and consumption-based water scarcity estimate, vis-à-vis scenarios of irrigation expansion and alternative reservoir routing schemes. The results show a negative impact of rainfed to irrigation-fed transition on urban water scarcity, indicating that poorly managed, extensive irrigation expansion can affect an additional 16 million urban population. Overall, the dissertation demonstrates the intricate connection between food and water security, highlighting their vulnerability and ways to mitigate them. Furthermore, it addresses the methodological challenges involved in assessing food and water security. The insights gained from this research can help support more informed decision-making to secure our water and food resources.

Grantor dc:publisher

University of Alabama Libraries

Year dc:date.issued

2024

Author dc:creator

• Rathore, Lokendra Singh

Advisor dc:contributor.advisor

• Kumar, Mukesh

Contributors dc:contributor

• Moftakhari, Hamed
• Moradkhani, Hamid
• Mekonnen, Mesfin
• Magliocca, Nicholas

• climate impact
• food security
• food-water nexus
• water security

Statement dc:rights

• All rights reserved by the author unless otherwise indicated.

Language dc:language.iso

en_US, English

Dc Identifier Other

1099055

OAI identifier oai:identifier

oai:ir.ua.edu:123456789/15346