Left panel: comparison between the DK Cha Brackett decrement and a model assuming an expanding wind in LTE at T = 3500 K. The other parameters of the model are: r_i = 1 R_⊙, r_out = 5 R_⊙,  = 10¹³ cm^-3, V₀ = 20 km s^-1, V_max = 300 km s^-1 and α = 3 (see text for details). Right panel: comparison between the DK Cha Paschen decrement and the same model assuming an expanding wind in LTE at T = 3500 K and r_i = 3 R_⊙ (dashed-dot black line) and at T = 2000 K and r_i = 2 R_⊙ (continuous red line). The other model parameters are the same as in the Brackett decrement case. For comparison the weighted mean line ratios for the Paschen series on the CTTSs sample of Bary et al. (2008, open green squares) were also included.