Derdar et al. (2026) Satellite-Based Estimation of Actual Evapotranspiration in an Arid Oasis Using the ALARM Model

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Water
• Year: 2026
• Date: 2026-10-29
• Authors: Banan Derdar, Ihab Jnad, Youns Idriss, Ana R. Oliveira, Tiago B. Ramos, Hanaa Darouich
• DOI: 10.3390/w18212706

Research Groups

[Information not provided in the paper text.]

Short Summary

This study evaluated the Analytical Land–Atmosphere Radiometer Model (ALARM) for estimating actual evapotranspiration (ETa) in heterogeneous perennial tree systems within an arid environment. ALARM successfully reproduced the seasonal dynamics of ETa, demonstrating its potential for crop water use assessment in such challenging conditions.

Objective

• To evaluate the performance of the Analytical Land–Atmosphere Radiometer Model (ALARM) for estimating actual evapotranspiration (ETa) in heterogeneous perennial tree systems in an arid environment, by comparing model estimates with eddy covariance measurements.

Study Configuration

• Spatial Scale: Palmyra Oasis, Syria (field/oasis scale, focusing on heterogeneous perennial tree systems).
• Temporal Scale: Two growing seasons (2004 and 2005).

Methodology and Data

• Models used: Analytical Land–Atmosphere Radiometer Model (ALARM).
• Data sources: Eddy covariance (EC) flux tower measurements, MODIS observations (2005), meteorological data.

Main Results

• ALARM accurately reproduced the seasonal dynamics of ETa across the study area.
• Model performance metrics for ETa were: Root Mean Square Error (RMSE) from 0.72 to 0.73 mm d⁻¹, Normalized Root Mean Square Error (NRMSE) from 27.11% to 28.16%, and Percent Bias (PBIAS) from 2.24% to 12.40%.
• The model showed a tendency to overestimate ETa during the early growing season and slightly underestimate it during the peak season, consistent with seasonal changes in available energy and surface thermal conditions.
• The results demonstrate ALARM's potential for assessing crop water use in arid perennial tree systems.

Contributions

• Provides a comprehensive evaluation of the ALARM model for estimating ETa in complex, heterogeneous arid perennial tree systems, a challenging environment for ETa estimation.
• Demonstrates the applicability and potential of ALARM for practical irrigation management and crop water use assessment in such specific agricultural settings.
• Highlights specific limitations of the model related to short-term variability, guiding future model improvements and applications.

Funding

[Information not provided in the paper text.]

Citation

@article{Derdar2026SatelliteBased,
  author = {Derdar, Banan and Jnad, Ihab and Idriss, Youns and Oliveira, Ana R. and Ramos, Tiago B. and Darouich, Hanaa},
  title = {Satellite-Based Estimation of Actual Evapotranspiration in an Arid Oasis Using the ALARM Model},
  journal = {Water},
  year = {2026},
  doi = {10.3390/w18212706},
  url = {https://doi.org/10.3390/w18212706}
}