IDEAS home Printed from https://ideas.repec.org/a/spr/waterr/v39y2025i9d10.1007_s11269-025-04151-4.html
   My bibliography  Save this article

Extra Dimensions to the Calibration of Hargreaves-Samani Equation Under Data-Scarce Environment

Author

Listed:
  • Ammar Ahmed Musa

    (King Fahd University of Petroleum and Minerals)

  • Nadir Ahmed Elagib

    (University of Cologne)

Abstract

Evapotranspiration estimates are paramount for understanding climatology and better water management, especially in regions notorious for recurrent droughts, high evapotranspiration losses and basins with overspilling. This study adds new dimensions to the adjustment of the Hargreaves-Samani model (HS) against the standard FAO Penman-Monteith method for estimating reference evapotranspiration. The original coefficient (C = 0.0023) and the overall exponent (E = 1.0) in HS are calibrated and validated while splitting and exchanging of odd and even years’ datasets. Sudan and South Sudan are selected as a case of least studied and data-scarce countries though encompassing the largest part of the Nile basin with diverse hydroclimate zones. Implications of the proposed dimensions for the results and their usage in water management are discussed. Data splitting in the present manner reveals variation in the results between the different datasets, depending on the geographical location and the associated climate as well as the season. Thus, data splitting avoids bias towards certain mode of climate in a changing world and subsequent misinterpretation. Both C and E increase linearly with latitude from the dry sub-humid to the hyper-arid zone. The resulting latitude dependence offers interpolation and extrapolation of the constants across this large yet understudied region. Least calibration characterized the wettest months whereas largest calibration distinguished the transitional months towards the dry/cool season. Adjusting C is more suitable for the hyper-arid and semi-arid zones as well as for the hot and wet seasons. Calibrating E suits better the arid and dry sub-humid zones in addition to the dry/cool season. The present results (mis)match results reported in the literature for similar climate zones, thus opening venues for further studies elsewhere.

Suggested Citation

  • Ammar Ahmed Musa & Nadir Ahmed Elagib, 2025. "Extra Dimensions to the Calibration of Hargreaves-Samani Equation Under Data-Scarce Environment," Water Resources Management: An International Journal, Published for the European Water Resources Association (EWRA), Springer;European Water Resources Association (EWRA), vol. 39(9), pages 4277-4294, July.
    • Handle: RePEc:spr:waterr:v:39:y:2025:i:9:d:10.1007_s11269-025-04151-4
    DOI: 10.1007/s11269-025-04151-4
    as

    Download full text from publisher

    File URL: http://link.springer.com/10.1007/s11269-025-04151-4
    File Function: Abstract
    Download Restriction: Access to the full text of the articles in this series is restricted.
    File URL: https://libkey.io/10.1007/s11269-025-04151-4?utm_source=ideas
    LibKey link: if access is restricted and if your library uses this service, LibKey will redirect you to where you can use your library subscription to access this item
    ---><---

    As the access to this document is restricted, you may want to

    for a different version of it.

    References listed on IDEAS

    as
    1. Sentelhas, Paulo C. & Gillespie, Terry J. & Santos, Eduardo A., 2010. "Evaluation of FAO Penman-Monteith and alternative methods for estimating reference evapotranspiration with missing data in Southern Ontario, Canada," Agricultural Water Management, Elsevier, vol. 97(5), pages 635-644, May.
    2. Raziei, Tayeb & Pereira, Luis S., 2013. "Estimation of ETo with Hargreaves–Samani and FAO-PM temperature methods for a wide range of climates in Iran," Agricultural Water Management, Elsevier, vol. 121(C), pages 1-18.
    3. Feng, Yu & Jia, Yue & Cui, Ningbo & Zhao, Lu & Li, Chen & Gong, Daozhi, 2017. "Calibration of Hargreaves model for reference evapotranspiration estimation in Sichuan basin of southwest China," Agricultural Water Management, Elsevier, vol. 181(C), pages 1-9.
    Full references (including those not matched with items on IDEAS)

    Most related items

    These are the items that most often cite the same works as this one and are cited by the same works as this one.
    1. Xiang, Keyu & Li, Yi & Horton, Robert & Feng, Hao, 2020. "Similarity and difference of potential evapotranspiration and reference crop evapotranspiration – a review," Agricultural Water Management, Elsevier, vol. 232(C).
    2. Kim, Ho-Jun & Chandrasekara, Sewwandhi & Kwon, Hyun-Han & Lima, Carlos & Kim, Tae-woong, 2023. "A novel multi-scale parameter estimation approach to the Hargreaves-Samani equation for estimation of Penman-Monteith reference evapotranspiration," Agricultural Water Management, Elsevier, vol. 275(C).
    3. Cruz-Blanco, M. & Lorite, I.J. & Santos, C., 2014. "An innovative remote sensing based reference evapotranspiration method to support irrigation water management under semi-arid conditions," Agricultural Water Management, Elsevier, vol. 131(C), pages 135-145.
    4. Martí, Pau & López-Urrea, Ramón & Mancha, Luis A. & González-Altozano, Pablo & Román, Armand, 2024. "Seasonal assessment of the grass reference evapotranspiration estimation from limited inputs using different calibrating time windows and lysimeter benchmarks," Agricultural Water Management, Elsevier, vol. 300(C).
    5. Paredes, P. & Pereira, L.S. & Almorox, J. & Darouich, H., 2020. "Reference grass evapotranspiration with reduced data sets: Parameterization of the FAO Penman-Monteith temperature approach and the Hargeaves-Samani equation using local climatic variables," Agricultural Water Management, Elsevier, vol. 240(C).
    6. Paredes, Paula & Martins, Diogo S. & Pereira, Luis Santos & Cadima, Jorge & Pires, Carlos, 2018. "Accuracy of daily estimation of grass reference evapotranspiration using ERA-Interim reanalysis products with assessment of alternative bias correction schemes," Agricultural Water Management, Elsevier, vol. 210(C), pages 340-353.
    7. Vásquez, Cristina & Célleri, Rolando & Córdova, Mario & Carrillo-Rojas, Galo, 2022. "Improving reference evapotranspiration (ETo) calculation under limited data conditions in the high Tropical Andes," Agricultural Water Management, Elsevier, vol. 262(C).
    8. Gonçalo C. Rodrigues & Ricardo P. Braga, 2021. "Estimation of Reference Evapotranspiration during the Irrigation Season Using Nine Temperature-Based Methods in a Hot-Summer Mediterranean Climate," Agriculture, MDPI, vol. 11(2), pages 1-13, February.
    9. Paredes, Paula & Trigo, Isabel & de Bruin, Henk & Simões, Nuno & Pereira, Luis S., 2021. "Daily grass reference evapotranspiration with Meteosat Second Generation shortwave radiation and reference ET products," Agricultural Water Management, Elsevier, vol. 248(C).
    10. Yan, Shicheng & Wu, Lifeng & Fan, Junliang & Zhang, Fucang & Zou, Yufeng & Wu, You, 2021. "A novel hybrid WOA-XGB model for estimating daily reference evapotranspiration using local and external meteorological data: Applications in arid and humid regions of China," Agricultural Water Management, Elsevier, vol. 244(C).
    11. Yang, Yang & Luo, Yufeng & Wu, Conglin & Zheng, Hezhen & Zhang, Lei & Cui, Yuanlai & Sun, Ningning & Wang, Li, 2019. "Evaluation of six equations for daily reference evapotranspiration estimating using public weather forecast message for different climate regions across China," Agricultural Water Management, Elsevier, vol. 222(C), pages 386-399.
    12. Santos, Reginaldo Ferreira & Bassegio, Doglas & de Almeida Silva, Marcelo, 2017. "Productivity and production components of safflower genotypes affected by irrigation at phenological stages," Agricultural Water Management, Elsevier, vol. 186(C), pages 66-74.
    13. Choudhury, B.U. & Singh, Anil Kumar & Pradhan, S., 2013. "Estimation of crop coefficients of dry-seeded irrigated rice–wheat rotation on raised beds by field water balance method in the Indo-Gangetic plains, India," Agricultural Water Management, Elsevier, vol. 123(C), pages 20-31.
    14. Luis Santos Pereira, 2017. "Water, Agriculture and Food: Challenges and Issues," Water Resources Management: An International Journal, Published for the European Water Resources Association (EWRA), Springer;European Water Resources Association (EWRA), vol. 31(10), pages 2985-2999, August.
    15. Patrícia Costa Silva & Matheus Batista Sabino & Maria Beatriz Ferreira & Narla Costa Oliveira Sabino & Larissa Silva Sousa & Mariana Batista Elias & Amanda de Brito Silva & Ana Flávia Alves Ferreira &, 2025. "Agronomic Effects of Different Rock Powder Rates Associated with Irrigation Water Depths: Potential for Lettuce ( Lactuca sativa L.) Production," Agriculture, MDPI, vol. 15(6), pages 1-17, March.
    16. Xue, Jingyuan & Fulton, Allan & Kisekka, Isaya, 2021. "Evaluating the role of remote sensing-based energy balance models in improving site-specific irrigation management for young walnut orchards," Agricultural Water Management, Elsevier, vol. 256(C).
    17. Yudong Wang & Guibin Pang & Tianyu Wang & Xin Cong & Weiyan Pan & Xin Fu & Xin Wang & Zhenghe Xu, 2024. "Future Reference Evapotranspiration Trends in Shandong Province, China: Based on SAO-CNN-BiGRU-Attention and CMIP6," Agriculture, MDPI, vol. 14(9), pages 1-22, September.
    18. Traore, Seydou & Zhang, Lei & Guven, Aytac & Fipps, Guy, 2020. "Rice yield response forecasting tool (YIELDCAST) for supporting climate change adaptation decision in Sahel," Agricultural Water Management, Elsevier, vol. 239(C).
    19. Elbeltagi, Ahmed & Deng, Jinsong & Wang, Ke & Malik, Anurag & Maroufpoor, Saman, 2020. "Modeling long-term dynamics of crop evapotranspiration using deep learning in a semi-arid environment," Agricultural Water Management, Elsevier, vol. 241(C).
    20. Xing, Liwen & Cui, Ningbo & Liu, Chunwei & Zhao, Lu & Guo, Li & Du, Taisheng & Zhan, Cun & Wu, Zongjun & Wen, Shenglin & Jiang, Shouzheng, 2022. "Estimation of daily apple tree transpiration in the Loess Plateau region of China using deep learning models," Agricultural Water Management, Elsevier, vol. 273(C).

    More about this item

    Keywords

    ;
    ;
    ;
    ;
    ;
    ;
    ;

    Statistics

    Access and download statistics

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:spr:waterr:v:39:y:2025:i:9:d:10.1007_s11269-025-04151-4. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a bibliographic reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: Sonal Shukla or Springer Nature Abstracting and Indexing (email available below). General contact details of provider: http://www.springer.com .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.