塔里木河流域人工与天然绿洲转化过程与适宜比例初探

在我国内陆河流域,社会经济的迅速发展导致人工绿洲急剧扩大,天然绿洲日益萎缩,确定人工与天然绿洲适宜的面积比例对绿洲可持续发展具有重要意义。本文以塔里木河流域为研究对象,利用遥感影像数据将流域各子流域划分为不同绿洲分布模式,选取克里雅河流域、渭-库河流域和叶尔羌河流域为各模式典型流域,分析各流域近20年人工与天然绿洲的转化过程,利用生态环境状况指数法评价各流域过去20年的生态环境状况,确定各模式下人工与天然绿洲适宜面积适宜比例。结果表明:(1)塔里木河流域各子流域划分为内陆河沙漠区模式、冲洪积扇形模式和干流模式;(2)典型流域绿洲总面积近20年变化不明显,人工与天然绿洲面积比例呈增加趋势,人工绿洲侵占天然绿洲,人口增长、耕地扩张和社会经济发展成为研究区绿洲变化的主要驱动力;(3)三种模式人工与天然绿洲面积适宜比例分别为3:7~4:6、4:6~5:5和≤4:6。本研究不仅为研究区绿洲规模规划提供科学依据,也为相似内陆河流域人工与天然绿洲面积比例的确定提供借鉴。

Transformation Process and Appropriate Area Proportion of Artificial and Natural Oases in the Tarim River Basin

In inland river basins of China,rapid development of social economy leads to huge expansion of artificial oases and continuous shrinking of natural oases.It is significant to oasis sustainable development that the determination of the appropriate area proportion of artificial and natural oases.Therefore,in this paper,the Tarim River Basin was chosen as study area,and its nine sources streams and main stream were divided into different patterns based on remote sensing image data.The representative river basins of 3 patterns are the Keriya River Basin,the Wigan-Kuche River Basin and the Yarkant River Basin respectively.Then,this paper analyzed their transformation processes of artificial and natural oases and assessed the eco-environment conditions by the eco-environment condition index method over the past 20 years.Finally,the appropriate artificial and natural oases area proportion under the 3 patterns were determined.The results showed that:(1) Nine sources streams and main stream were divided into inland river desert area pattern,alluvial-proluvial fan pattern and main stream pattern;(2) The total oasis areas of the representative river basins had no clear change in recent 20 years,but the area proportion of artificial and natural oasis increased.The artificial oasis occupied the natural oasis.Population growth,cultivated land expansion and social and economic development were the main driving forces of oasis change;(3) The appropriate area proportion of artificial to natural oases in the 3 patterns were 3 ∶ 7～4 ∶ 6,4 ∶ 6～5 ∶ 5 and-≤ 4 ∶ 6,respectively.This study not only provided scientific basis for oasis scale planning in the study area,but also offered references for the determination of appropriate artificial and natural oases area proportion in similar inland river basins.