radex results for the average line ratios for the cavity shock components assuming a kinetic temperature of T = 300 K. The top panels corresponds to the intermediate-mass object NGC 7129 FIRS2 in which no infrared radiation field has been included. The middle and bottom panels show the results for the high-mass YSOs G10.47+0.03 without and with radiation field respectively. For each row, the left-hand panels show the best-fit (red cross), the 1, 3 and 5σ confidence limits (blue contours) for a grid in n_H2 and N_H2O and the corresponding size of the emitting region in AU (black dashed lines). The middle panels show a spectral line energy distribution comparing the observed and best-fit model with blue and red symbols respectively. Finally, the right-hand panels present the optical depth, τ, of the best-fit model for each H₂O line.