Climate change impacts on water sustainability of South African crop production

• Published in: Environmental research letters Vol. 17; no. 8; pp. 84017 - 84027
• Main Authors: Bonetti, Sara, Sutanudjaja, Edwin H, Mabhaudhi, Tafadzwanashe, Slotow, Rob, Dalin, Carole
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.08.2022
• Subjects: Agricultural production; Arid regions; Arid zones; Climate change; Cotton; Crop production; Environment and Society; Environmental impact; Environmental Sciences; Food security; Irrigation; Land use; Land use management; Land use planning; Letter; Semi arid areas; Semiarid zones; South African crop production; Spatial distribution; Sustainability; Sustainability management; Water consumption; water debt indicator; water footprint; Water management; Water requirements; Water resources; Water resources management; water sustainability; Water use; South Africa
• ISSN: 1748-9326; 1748-9326
• DOI: 10.1088/1748-9326/ac80cf

Agricultural production in arid and semi-arid regions is particularly vulnerable to climate change, which, combined with projected food requirements, makes the sustainable management of water resources critical to ensure national and global food security. Using South Africa as an example, we map the spatial distribution of water use by seventeen major crops under current and future climate scenarios, and assess their sustainability in terms of water resources, using the water debt repayment time indicator. We find high water debts, indicating unsustainable production, for potatoes, pulses, grapes, cotton, rice, and wheat due to irrigation in arid areas. Climate change scenarios suggest an intensification of such pressure on water resources, especially in regions already vulnerable, with a country-scale increase in irrigation demand of between 6.5% and 32% by 2090. Future land use planning and management should carefully consider the spatial distribution and local sustainability of crop water requirements to reduce water consumption in water risk hotspots and guarantee long-term food security.