An even-better view of the suspected water-ice distribution in Mars' upper surface. The previously posted article's graphics only showed the southern hemisphere.

As with the cosmic radiation exposure rates, the more interesting regions seem to have little going for them in terms of near-surface water-ice availability. Indeed, the areas in which one would expect to find some sort of hydrothermal activity (the comparatively young volcanoes of Tharsis) appear to be dry.

Of course, since this survey only concerns the upper three feet of the planet's surface, it doesn't preclude the existence of exploitable aquifers deep beneath the surface. It's no more valid to conclude from this data that Mars has too little water to support settlement than it would be to conclude from data on the hydrocarbon content of the upper three feet of Earth's surface that there is insufficient petroleum to support globe-spanning energy and petrochemical industries.

We just don't know. Yet.