Temporal variations in the water footprint (WF) of crop production have been less studied compared to spatial variations. This study analyzed global spatiotemporal trends in the WF of crop production from 1972 to 2018 at 5 arcmin (0.0833°) resolution using a process-based crop model, alongside statistical analysis to identify key socio-economic drivers. The global WF increased from 4,799 km3 in 1972 to 7,773 km3 in 2018, with blue and green WFs rising by 65% and 61%, respectively, driven by growing demands for food, feed, biofuels, and other uses. A 36% increase in crop area was found to be the primary contributor, while increased crop productivity through land intensification helped offset further increases. The rise in WF was driven primarily by oil crops, cereals, and fruits. Green water accounted for 84% of the WF increase, emphasizing the need for better green water management. Population growth, livestock production, agricultural exports, GDP, and biofuel demand were identified as key socio-economic drivers, offering insights into targeted strategies for sustainable water use in agriculture.
Demeke et al. (Fri,) studied this question.