If you're including a Storch, your ground surface, I imagine any way, would have to be sturdy enough to support an aircraft landing and taking off. Much like this photo seen here (for discussion purposes only)
Its more packed sand and rock rather than soft, sprawling sand dunes such as this
For a seen I created in a desert like environment, I used celluclay mixed with some real dirt for added texture. Then painted it with artist oils and added some real stones and cat litter for larger rocks and variations in the ground surface...
You can add some vegetation to break up the monotony by getting some fake plants from a craft store or another vendor, like Woodland Scenics may have something you like.