Qualitative evolution of the amount of water vapor in the atmosphere as a function of the total water inventory, assuming a synchronous rotation and a liquid water runoff activated, for three different scenarios: a quasi-flat topography, a basin at the substellar point, and a basin at the anti-stellar point. For high pCO₂, the range of water inventory for which the three scenarios diverge would flatten on a logarithmic scale because potentially high amount of water could be vaporized.