查看文章

Crop coefficient (K_c)-based estimation of crop water consumption is one of the most commonly used methods for irrigation management. Spectral modeling of K_c is possible due to the high correlations between K_c and the crop phenologic development and spectral reflectance. In this study, cotton evapotranspiration was measured in the field using several methods, including eddy covariance, surface renewal, and heat pulse. K_c was estimated as the ratio between reference evapotranspiration and the measured cotton evapotranspiration. In addition, a time series of Sentinel-2 imagery was processed to produce 22 vegetation indices (VIs) based on the sensor’s unique spectral bands. Empirical K_c – VI models were derived and ranked according to their prediction error. In accordance with previous studies, we found a strong correlation between the normalized difference vegetation index (NDVI) and K_c (R² = 0.94 …