Regions for outward migration in discs with different water-to-silicate ratios (Z_dust = 0.5%) and different times for planets in type-I-migration. Planets located inside of the solid lines migrate outwards, while planets outside the lines migrate inwards. As the disc evolves in time, the strong negative gradients in entropy indicated by radial decreases in H/r (Fig. 2) move towards the star and thus the regions of outward migration move inwards. The small ticks on the top of the plot correspond to the location of the ice line for the different simulations. A clear difference in the regions of outward migration for the different ice to silicate ratios is visible for early times, while the differences become smaller for late evolution times.