广义的沙漠等同于荒漠，都是指气候干燥，降水稀少，蒸发量大，植被贫乏 的地方；狭义的沙漠是荒漠的一种类型——沙质荒漠，地面上覆盖着由石英等细 小矿物颗粒组成的松散堆积物，在风的吹扬下形成大小、形态各异的沙丘，沙丘 之间面积不等的丘间地，构成了连绵起伏的浩瀚沙海。阿拉善沙漠包括巴丹吉林、 腾格里和乌兰布和三大沙漠。

　　In the broad sense, desert and barren sandy land are the same, both being places of dry climate, low rainfall, high evaporation and poor vegetation. In the narrow sense, however, desert is one particular type of barren sandy land whose surface is covered with unconsolidated deposits consisting of small mineral granules, like quartz. These substances are carried by the wind to form sand dunes with various profiles. With interdunal lands in between, the undulating dunes link together to form a great sea of sand. The Alxa Desert is made up of three deserts, Badain Jaran, Tengger and Ulan Buh Desert.