Gas temperature and H₂O column density distribution for the reference model. Contours of the gas temperature at 160, 200, 300, and 500 K are shown as red solid lines. The dashed contours refer to the water column density Log (N_H2O/cm⁻²) at 17 (black), 18 (blue), and 19 (green), where N_H2O is measured from the surface layer down to the midplane. The orange contour indicates the scale height with dust optical depth τ_20 μm = 1 measured from the surface layer to the midplane. The shaded area encloses the contours of Log (N_H2O/cm⁻²) = 17, T = 160,  500 K, and τ_20 μm = 1. This region contributes to most of the water vapor emission at mid-IR wavelengths.