The Largest Hot Desert in the World —The Sahara Desert 世界上最大的热沙漠 ——撒哈拉沙漠

The Sahara Desert is located in the northern part ofAfrica and covers about 9，600，000 square kilometers or32% of the continent. It is bounded in the east by the RedSea and it stretches west to the Atlantic Ocean. To thenorth， the Sahara Deserts northern boundary is theMediterranean Sea， while in the south it ends at theSahel， an area where the desert landscape transformsinto a semi-arid tropical savanna.

撒哈拉沙漠位于非洲北部，面積约960 万平方千米，占非洲大陆的32%。它东临红海，向西一直延伸到大西洋，北靠地中海，往南至萨赫勒终结。在萨赫勒，沙漠景观逐渐转变为半干旱热带稀树草原景象。

Since the Sahara Desert makes up 32% of the African continent， the Sahara is often cited as the worlds largest desert. This is not entirely true， however， as it is only the worlds largest hot desert. Based on the definition of a desert， as an area receiving less than 250 mm of precipitation per year， so the worlds largest desert is actually the continent of Antarctica.

由于撒哈拉沙漠占据了非洲大陆32%的面积，它常常被称为世界上最大的沙漠。然而，这种说法并不完全准确，因为它只是世界上最大的热沙漠。根据沙漠的定义——区域年降水量不足 250毫米的地区可以称为沙漠，所以南极洲大陆才是世界上最大的沙漠。

Although hot and extremely dry today， it is believed that the Sahara Desert has undergone various climatic shifts for the last few hundred thousand years . For example， during the last glaciation， it was larger than it is today because precipitation in the area was low. But from 8000 BC to 6000 BC，  precipitation  in the  desert increased because of the development of low pressure over ice sheets to its north. Once these ice sheets melted， however， the low pressure shifted and the northern Sahara dried out but the south continued to receive moisture due to the presence of a monsoon.

尽管如今沙漠的气候炎热干燥，但人们普遍认为撒哈拉沙漠在过去的几十万年里经历了各种气候变化。例如，在上一次冰川期，由于该区域降水量很低，它的范围比如今的更大。但从公元前8000年到公元前6000年，由于冰原低气压向北部发展，沙漠的降水量增加了。然而，一旦这些冰盖融化，低压就会转移，北撒哈拉地区也会干涸，但由于季风的存在，南部地区将继续受潮。

Most of the people living in the Sahara today do not live in cities; instead， they are nomads who move from region to regionthroughout the desert. Because of this， there are many different nationalities and languages in the region and Arabic is most widely spoken. For those who do live in cities or villages on fertile oases， crops and the mining of minerals like iron ore and copper are important industries that have allowed population to grow.

现在撒哈拉沙漠的居民都不是居住在城市中的，相反，他们不断从沙漠的一个区域迁移到另一个区域，过着游牧生活。因此，该地区存在许多不同民族和语言，其中使用最广泛的是阿拉伯语。对于那些生活在依靠绿洲建立的城市或村庄的人来说，农作物和矿产，例如铁矿石和铜矿等的开采是使人口得以增长的重要产业。

Word Study

stretch /stret?/ v.绵延;伸展;延续

Fields and hills stretched out as far as we could see.

precipitation /pr?'s?p?'te??n/ n.降水量（包括雨、雪、冰等）;沉淀

moisture /'m??st??r/ n.水汽;水分

nomad /'no?m?d/ n.游牧民;游牧生活