EVAPOTRANSPIRATION AND EVAPORATION/TRANSPIRATION RETRIEVAL USING DUAL-SOURCE SURFACE ENERGY BALANCE MODELS INTEGRATING VIS/NIR/TIR DATA WITH SATELLITE SURFACE SOIL MOISTURE INFORMATION

Our objective is to question the representation of the energy budget in surface–vegetation–atmosphere transfer models for the prediction of the convective fluxes in crops with complex structures (row) and under transient hydric regimes due to irrigation. The main result is that a coupled multiple energy balance approach is necessary to properly predict surface exchanges for these complex crops. It also points out the need for other similar studies on various crops with different sparsity levels.

The purpose of our work is to estimate landscape evapotranspiration (ET) fluxes over agricultural areas by relying on two surface modeling approaches with increasing complexity and input data needs. Both approaches, compared sequentially and over the entire crop cycle, showed quite similar performance except under developed vegetation and stressed conditions. This study helps lay the groundwork for exploring the complementarities between instantaneous and continuous ET mapping with TIR data.

This study presents an innovative method to assess irrigation volumes in the ISBA land surface model with high resolution optical remote sensing. We developed a new automated irrigation scheme which can adapt to a wide variety of crops and irrigation practices. Remotely sensed vegetation dynamics was used to drive its parameters. The simulation performed on several maize plots in south-western France shows an improvement on the simulated irrigation volumes and timing.