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我国西北地区有许多绿洲,它们好似一个个绿色的岛屿,分布在荒漠之中。绿洲中地势平坦,土壤肥沃,水热资源丰富。据考古证明,新石器时代就有人类在这里生息,汉代以后又成为我国移民屯垦的重要地区和边防要地。但是,绿洲地处荒漠之中,生态条件非常脆弱,由于人类活动的影响,往往导致荒漠化发生,河流改道,绿洲面积缩小,许多古代城镇和居民点,有的被流沙淹埋,有的变成废墟。所以绿洲中城镇和居民点的形成与变迁,一方面反映历代王朝对这一地区的经营过程,另一方面也反映了绿洲的自然地理面貌在人类历史时期的变化情况。
There are many oases in the northwest of our country. They are like green islands distributed in the desert. Oasis in the flat, fertile soil, rich in water and heat resources. According to the archeology, there were some people living here in the Neolithic Age. Since then, the Han Dynasty has become an important area for settling mines in our country and a frontier defense area. However, the oasis is located in the desert and its ecological conditions are very fragile. Due to the influence of human activities, the desertification often takes place, the rivers are diverted and the area of the oasis is reduced. Many ancient towns and settlements are sometimes submerged by quicksand and some become ruins . Therefore, the formation and change of towns and settlements in the oasis reflect on the one hand the business process of the dynasties in this area and on the other hand reflect the changes of the natural geography of the oasis in the historical period of mankind.