Evaluation of the effects of climate change on field-water demands using limited ground information: a case study in Balkh province, Afghanistan

Climate change is a significant global issue that will affect regional agriculture and water management of irrigation supplies. In this study, we project climate change impacts on water and irrigation requirements for major crops—wheat, cotton, and apricots—in Balkh province, Afghanistan. The methodology utilizes satellite imagery to overcome limitations in ground measurements necessary to understand current crop conditions and cultivation schedules for the study site. The climate model-averaged results project an increasing trend in both crop water and irrigation requirements for the study area, with larger trends for the climate model and scenario combinations that project the largest temperature increases. Future trends in the year-to-year variability of field water requirements do not contain a clear trend for most crops. The magnitude of projected changes vary significantly between individual climate models, demonstrating the importance of applying multiple climate models to project future conditions in agricultural water management. The results demonstrate the efficacy of using globally available data, including satellite imagery and global climate model information, to overcome lack of in situ observations. The findings also highlight challenges to current agricultural paradigms in areas such as Afghanistan that are arid to semi-arid and do not have adequate irrigation infrastructure.