EGU General Assembly 2021
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Analysis of diurnal cycles of interferometric coherence and backscattering coefficient measured on an irrigated wheat field in Morocco

Nadia Ouaadi1,2, Ludovic Villard2, Jamal Ezzahar3,4, Pierre-louis Frison5, Saïd Khabba1,4, Adnane Chakir1, Salah Er-raki4,6, and Lionel Jarlan2
Nadia Ouaadi et al.
  • 1LMFE, Department of Physics, Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakech, Morocco (
  • 2CESBIO, University of Toulouse, IRD/CNRS/UPS/CNES, Toulouse, France
  • 3MISCOM, National School of Applied Sciences, Cadi Ayyad University, Safi, Morocco
  • 4CRSA, Mohammed VI Polytechnic University UM6P, Ben Guerir, Morocco
  • 5LaSTIG, UPEM / IGN, Champs sur Marne, Paris, France
  • 6ProcEDE, Department of Applied Physique, Faculty of Sciences and Technologies, Cadi Ayyad University, Marrakech, Morocco

C-band radar observations have shown a high sensitivity to the water status of vegetation, including forests and crops. Several studies conducted mainly on forests have observed daily changes of the backscattering coefficients between ascending and descending orbits and have suggested that these differences are related to the diurnal cycle of vegetation water content. Likewise, the water movement within annual crops could be associated to change of the phase centre locations leading to a daily cycle of the interferometric coherence as well that has already been observed on tropical forest using C-band in situ acquisitions. In this context, an experimental setup composed of 4C-band antennas targeting an irrigated wheat field was installed at the top of a 20 m tower near Chichaoua (Morocco) from January to June 2020. The collected data includes measurements of the backscattering coefficient at both cross- and parallel polarizations and the interferometric coherence with a 15 mns time step. The field is also equipped with an eddy-correlation station for half hourly measurements of convective fluxes, soil moisture and temperature profiles. Simultaneously, measurement of above-ground biomass, leaf area index, canopy height and surface roughness are also carried out every 15-daysduring the agricultural season.  The preliminary results of the experiment reveal the existence of strong correlation between the daily evolution of interferometric coherence and the physiological activity of wheat at dawn while the changes observed in the afternoon are ratherrelated to the wind peaks. For the backscattering coefficient, a good agreement is observed between the evolution of its daily average and the evolution of evapotranspiration. These open insights for the monitoring of the crops water status using radar dataacquired at sub-daily timescale.

How to cite: Ouaadi, N., Villard, L., Ezzahar, J., Frison, P., Khabba, S., Chakir, A., Er-raki, S., and Jarlan, L.: Analysis of diurnal cycles of interferometric coherence and backscattering coefficient measured on an irrigated wheat field in Morocco, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14849,, 2021.


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