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干旱区已经引起全世界的普遍关注。绿洲和荒漠一起出现在全球的干旱区,分布十分广泛。其形成原因有二:一是由于受副热带高压的的控制,荒漠主要集中在北回归线和南回归线两侧的地带。此地带内形成了延绵数千公里的热带荒漠和副热带荒漠。其二,因受大地形、陆海分布和洋流的影响等非地带性因素的影响,荒漠还出现在大致南北纬35°至45°的地区。在这些广阔成带的荒漠里镶嵌着明珠般的绿洲,有些甚至是人类文明的摇篮。在绿洲基础上建立的绿洲
Arid zones have caused widespread concern around the world. Oasis and desert appear together in arid regions of the world and are widely distributed. The formation of two reasons: First, due to the subtropical high pressure control, the desert is mainly concentrated in the Tropic of Cancer and the Tropic of cancer on both sides of the strip. The belt has formed thousands of kilometers of stretches of tropical and subtropical deserts. Second, due to the influence of non-zonal factors, such as the large topography, the distribution of land and sea and the influence of ocean currents, the deserts also appear in the regions roughly 35 ° to 45 ° north and south latitudes. In these vast belt of the desert inlaid with a pearl oasis, and some even the cradle of human civilization. Oasis built on the oasis