Using NDVI for the assessment of canopy cover in agricultural crops within modelling research

The fraction of green canopy cover (CC) is an important feature commonly used to characterize crop growth and for calibration hydrological models. It well accepted that there a relation between CC NDVI through linear or quadratic models, however straight-forward empirical approach, derive from observations, still lacking. In this study, we conducted meta-analysis the NDVI-CC relationships with data collected 19 different studies (N = 1397). Generic models are proposed here 13 agricultural crops, associated degree uncertainty, together magnitude error were quantified each model (RMSE around 6–18% CC). We observed correlations adequate majority crops as R2 values above 75% most cases, coefficient estimates significant Extrapolation conditions than those found in may require local validation, obtained regressions affected by non-sampling errors sources systematic need further investigation. case study wheat, tested use proxy estimate calibrate AquaCrop model. Simulation outcomes validated field three growing seasons confirmed relationship was useful modelling research. highlight overall applicability these promising RMSE line acceptable levels published several sensitivity analyses.