The issues such as determination of the area-avearged evaporation, and sensible heat flux over a heterogeneous land surface of the EVA-GRIPS project was described. Through a combination of near-surface and boundary layer observations, the analysis of satellite data and numerical simulations EVA-GRIPS aims at testing and implementing concepts for the description of area-avearged turbulent fluxes in land surface schemes. In the project, eddy correlation instruments were placed at 13 sites over different land use types and vertical profiles in the boundary layer were sampled by lidar and radar. The project combine model and satellite data with the in-situ measurements to analyze the validity of the evaporation parameterization in atmospheric models.