| Although some major rivers, such as the Nile, cross desert areas, bringing a permanent supply of fresh water, most life must rely on ground water, which occasionally nears the surface at an oasis. On the south side of the Takla Makan Desert in western China, a series of large oases occur at the base of the Kunlun Shan Mountains where ground water is forced to the surface by a change in rock type. 
The large oases at the foot of the Kunlun Shan were stops on the ancient trade routes of the Silk Road. |
