Nomads adapt to life.  They move around all over the desert.  When needing to stay over night they will set up a tent.  Their always on the move so portable tents will make it easier to settle.

Oasis's in Saudi Arabia provide not only shade but also nutrition. For people and animals that have been walking for miles water will help keep them alive.  Oasis's also provide vegitation for the area.  Usually not much vegitation grows in desesrts so the trees or plants that grow around the oasis will  provide much relaxing shade.

Camels were prime recourses for travel.  The nice water is a typical oasis.