Evaluating Crop Water Requirements: A Case Study of Date Palms in Water-Scarce Jordan

The rapid expansion of date palm cultivation in Jordan presents significant challenges related to water management, particularly as the region faces increasing water scarcity. This study addresses the urgent need for precise estimation of crop water requirements by evaluating the actual daily evapotranspiration (ETa) of date palms. We employed the Analytical Atmospheric Land Radiation Measurement (ALARM) model and compared its performance with the Evapotranspiration Look (ETLook) model to determine their effectiveness in capturing the water needs of these crops. Utilizing six satellite images from Landsat 8 and 9, we conducted our analysis over a period from February 9 to May 15, 2024. The results indicated that the ALARM model produced ETa values ranging from 2.58 mm/day to 5.23 mm/day, with an average of approximately 4.23 mm/day. In contrast, the ETLook model, which relies on data from the WaPOR portal and incorporates MODIS and PROBA-V satellite information, yielded significantly lower estimates, with values between 0.975 mm/day and a maximum of 2.125 mm/day This discrepancy suggests that the ETLook model may adopt a conservative approach, potentially underestimating the water requirements during critical growth phases, which could adversely impact crop health and yield. Furthermore, the average root mean square error (RMSE) between the two models was approximately 2.7 mm/day, indicating variability in their performance. The findings emphasize the ALARM model’s superiority for detailed assessments in heterogeneous landscapes, making it particularly suitable for optimizing irrigation strategies tailored to the specific needs of date palms. Conversely, the ETLook model may be better suited for broader regional assessments, providing a more generalized view of water consumption. In conclusion, integrating both models can enhance water use efficiency and support sustainable agricultural practices in water-scarce environments. By improving our understanding of ETa dynamics in date palm cultivation, this study contributes valuable insights for effective water resource management and the long-term sustainability of agricultural systems in Jordan and similar arid regions