Effect of the stellar and disk parameters on the OH and H₂O emission. OH is primarily sensitive to the stellar FUV flux, which depends on L_acc, on the inclusion of Lyα photons, and on the gas-to-dust ratio. The H₂O line flux is sensitive to the bolometric luminosity of the star and the gas-to-dust ratio. In this figure the reference value of the parameters that are kept constant are d_gd = 10⁴, L_* = 1 L_⊙, and L_acc = 0.12 L_⊙. The line fluxes are calculated by integrating the H₂O emission from 12.5 to 12.537 μm and the OH emission from 10.05 to 10.08 μm.