Small agricultural reservoirs play a key role in supporting irrigation, local demands, and food security in a warming climate. However, evaporation diminishes their storage efficiency. We provide a mechanistic framework fusing remote sensing information with physics-based modeling to estimate global abundance of small water reservoirs and their evaporative losses. Application of the framework in water-stressed regions of Europe (Italy, Spain, and Portugal) indicated that cumulative area of small reservoirs has increased from 46 km2 in 2000 to 93.5 km2 in 2020. We found that evaporative losses from small water reservoirs during warm months (April to September) may exceed 72 million cubic meters accounting for 38% of their total storage capacity. The study offers new insights into the improved understanding of the role and efficiency of small water storage infrastructure in water planning strategies.

For more details, please check out our paper:
Aminzadeh, M., N. Friedrich, S. Narayanaswamy, K. Madani, and N. Shokri (2024), Evaporation loss from small agricultural reservoirs in a warming climate: An overlooked component of water accounting, Earth's Future, 12, e2023EF004050, https://doi.org/10.1029/2023EF004050