Abstract:
Global food production is increasingly threatened by water scarcity, underscoring the need to understand hydrological risks to agriculture. However, there is a critical gap in assessing crop-specific risks under blue water stress conditions at a global scale. This thesis addresses this gap by operationalising the IPCC risk-assessment framework and leveraging water footprint analysis to define an indicator: the Blue Water Dependency Index (BDI). The BDI captures the agro-hydrological vulnerability of rice, wheat, maize, and soybean production systems at the individual sub-basin level globally. Based on this index, crop production regions were categorised into four risk categories: ‘Highly Risky, High Dependence’, ‘Risky, Low Dependence’, ‘Secure, High Dependence’, and ‘Highly Secure, Low Dependence’. Further, descriptive estimates of the shares of global total and irrigated production for each crop were obtained to provide insights into the food security implications. The spatial risk assessment reveals that globally, 16.6% of rice and 10.2% of wheat are produced in ‘Highly Risky, High Dependence’ systems, presenting significant food security implications. Furthermore, this assessment identifies regions where exposure must be reduced and supports sustainable irrigation expansion strategies to meet growing food demands. Given the dual role of crop production as both a driver and a victim of blue water stress, this research highlights broader trade-offs and synergies in food production and water use. Ultimately, this assessment establishes a crucial hazard-specific baseline for future socio-economic vulnerability assessments and targeted agricultural policy.
