Abstract
Assessing associations between dry spell variability and green and blue water dynamics is essential for strengthening the resilience of rainfed agriculture. This study evaluated the associations between dry spell characteristics and green-blue water dynamics in the Upper Awash Basin, Ethiopia, using 35 years (1990–2024) of hydro-meteorological data from 10 meteorological stations, physiographic datasets, and SWAT+ model. Dry spell onset, cessation, duration, frequency, and intensity were integrated with hydrological responses through a hydroclimatic sensitivity framework. Model performance was satisfactory, with NSE = 0.61–0.79, R² = 0.66–0.84, and PBIAS = 1.17–7.01%. Results showed downstream intensification of dry spells, with seasonal duration increasing from 7 to 8 dekads upstream to 12 dekads downstream. ETa, representing green-water flow, accounted for 70.14% of seasonal components, while SW accounted for 5.98% and WYLD 23.88%, respectively. Dry spell duration showed the strongest significant association with evapotranspiration (β = -0.83 to -0.51). Blue water yield showed spatially varying negative associations: DSD dominated Subbasins 1 and 4, DSF Subbasin 2, and DSI Subbasins 6, 7, and 9. These findings indicate that greater dry spell severity is associated with changes in water partitioning and provide basis for integrating dry spell indicators into climate-resilient rainfed agricultural water management in the Upper Awash Basin.
Acknowledgements
The authors thank the National Meteorological Institute (NMI) and the Ministry of Water and Energy (MoWE) of Ethiopia for providing the weather and streamflow data records used in this study.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing interests.
Additional information
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary Information
Below is the link to the electronic supplementary material.
Supplementary Material 1 (download PDF )
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.
Reprints and permissions
About this article
Cite this article
Weletu, H.A., Gebul, M.A., Chukalla, A.D. et al. Associations of dry spell characteristics with green and blue water components under rainfed agriculture in the Upper Awash Basin, Ethiopia.
Sci Rep (2026). https://doi.org/10.1038/s41598-026-70667-3
Received:
Accepted:
Published:
DOI: https://doi.org/10.1038/s41598-026-70667-3
Keywords
- Dry spells
- Green and blue water
- Rainfed agriculture
- SWAT+ model
- Upper Awash Basin
- Water partitioning
Source: Resources - nature.com
