Fig. 7

Relationship between measured and predicted transpiration rate (E). E was measured with a portable LICOR infrared gas analyzer. (A) The first row visualizes the test prediction accuracy of thermal infrared (TIR) index-based models (CTD_out, CWSI_{Ta_out}, and T_dry-T_p), while the second row shows the performance of these indices when they are combined with environmental data not included in the index (Table 4). The third row contains two figures that show the accuracy of models that combine one TIR index (CTD_out or CWSI_{Ta_out}) with environmental data and hyperspectral indices (RMP_1483/1430, WBI). This type of model was not created for the T_dry-T_p index, as hyperspectral indices did not significantly contribute to this model (Chi-square test, P < 0.05). (B) Prediction accuracy of the LASSO, RF and PLSR models that combine multiple TIR indices with hyperspectral wavelengths and/or environmental data. The semi-transparent black dots represent the predicted and measured E of the 100 bootstrap samples, while the black line shows the one-to-one relationship. The test RMSE and R² are added to each scatterplot