Spatio-temporal variability of evapotranspiration and crop water requirement from space

Alexander Samuel*, Atkilt Girma, Amanuel Zenebe, Tesfaalem Ghebreyohannes

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

15 Citations (Scopus)


The Surface Energy Balance System (SEBS) algorithm very well captures the spatio-temporal Actual Evapotranspiration (AET) variability, which is relevant to compute Crop Water Requirement (CWR) of commercial farms during the dry season. Considering this, a study was conducted in the arid and semi-arid parts of middle Awash in Ethiopia using reflectance and radiance satellite datasets of both Moderate Resolution Imaging Spectroradiometer (MODIS) and Landsat's Operational Land Imager (OLI) sensors. The SEBS model e derived AET was compared with the CWR computed from ground (observed) meteorological datasets. The results revealed that the amount of AET over the study area was dependent on temperature, surface radiative property, moisture content and crop development stage. The AET derived from satellite datasets was strongly related to the ground computed CWR over the irrigated sugarcane and cotton fields. The study revealed that the technique could be of great help during irrigation management, water conservation and allocation. Hence, we recommend decision makers of the commercial farms to further explore the use of this technique to properly manage and schedule their irrigation.

Original languageEnglish
Pages (from-to)732-742
Number of pages11
JournalJournal of hydrology
Publication statusPublished - Dec 2018


  • Actual evapotranspiration
  • Crop water requirement
  • Remote sensing
  • Surface energy balance

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