Evolution of the surface density of the gas (violet curves) and the dust (pink curves) in the three scenarios with grains of size 0.1 μm, 20 μm, and 100 μm, assuming α = 10^-3. The solid lines represent the initial conditions at t = 10⁴ yr, while the dotted, dashed, and dash-dotted lines show the evolved profiles at 0.1, 1, and 3 Myr, respectively. The effect of the inward radial drift of the dust relative to the gas becomes stronger with increasing grain size. Note that the surface density of the dust does not include the mass contribution of the ice mantles beyond the snowlines.