新疆人工灌溉绿洲的形成和发展演变

新疆人工灌溉绿洲形成的自然条件取决于水文、地貌、土壤和植被,并与社会经济因素和生产活动方式、生产发展水平及人口增长密切相关.塔里木盆地的古绿洲多分布在河流中下游三角洲上;老绿洲多在冲积扇中下部和冲积平原;新绿洲则多在老绿洲的外围和边缘.吐鲁番盆地在依靠火焰山泉水灌溉时,绿洲在火焰山以南;18世纪以后,绿洲主要分布在依靠坎儿井灌溉的地方;20世纪50年代后,实行渠、库、井联合灌溉,绿洲原地不断扩大.天山北麓平原,绿洲最初在交通和军事据点,后发展成一条河一小块绿洲.1949年后由于农垦事业的发展,才将小块绿洲扩大连接成绿洲带.伊犁河谷,起初依靠山溪小河灌溉,绿洲只是小块分布在伊宁和霍城.此后,引伊犁河水,开发的土地多在河谷平原的阶地上,整个伊犁河谷成为新疆最大的绿洲之一.

Formation, Development and Evolution of the Artificially-irrigated Oases in Xinjiang

The natural conditions of forming artificially-irrigated oases in Xinjiang depend upon the hydrological conditions,landforms,soils and vegetation,and the social and economic factors are related to the patterns of productive activities,productive development level and population growth.However,Xinjiang is vast,and the formation and spatiotemporal evolution of the oases are different from the different regions in Xinjiang due to the difference in natural conditions and social development level.In the Tarim Basin,the paleo-oases are generally distributed on the deltas in the middle and lower reaches of rivers,the old oases are generally distributed in the central and lower parts of alluvial-diluvial fans and the alluvial plains,and the new oases are generally distributed in the peripheral regions of the old oases.In the Turpan Basin,the oases were distributed in the regions south from the Flame Mountain when they were irrigated with spring water from the Flame Mountain;the oases were mainly distributed in the regions where the lands could be irrigated with karezes after the 18th century;the oases dominated by fruit-tree forests and graperies have been continuously enlarged in situ after the canal-reservoir-well combined irrigation is implemented since the 1950s.In the plains on northern piedmont of the Tianshan Mountains,the oases were originally distributed along the traffic routes and in the regions where the martial beachheads were distributed,then the small oases were developed along the rivers,and these small oases have been enlarged and connected to be as the oasis zones because of the development of reclamation since 1949.In the Yili River valley,the small oases were originally distributed in Yining and Huocheng regions only,and they were irrigated with stream water from the streams and small rivers;and then the reclaimed lands are mainly distributed on terraces in the valleys after leading in stream water from the Kax River and Yili River.Agriculture has been rapidly developed since 1949,and the whole Yili River valley has become as one of the largest oases in Xinjiang.