Sand

Aside from the fact that it piles up in dunes, the sand in Journey acts an awful lot like water. It's known to pour in sandfalls, flow through "aqueducts", and ripple from a player's chirp. That detail, with the fact that many cloth creatures resemble aquatic things, implies that Rythulia is buried under a literal "ocean" of sand.

Snow
Mechanically speaking, Snow in Journey is basically white-colored sand.

In the beta
In the beta, sand would ripple in front of Wayfarers, and even "splash" in the Broken Bridge level. This made the analog to water even more obvious.