近35 a来新疆干旱区湖泊变化及原因分析

应用“3S”技术，以流域为单元，对新疆干旱区1975-2010年近35 a来湖泊的变化进行了研究。研究结果表明：湖泊总体呈数量多、规模小的特点，以天然湖泊为主，湖泊分布面积最大的流域为准噶尔内流区、分布数量最多的流域为塔里木内流区；35 a来湖泊的变化呈1975-2000年数量与面积增大、2000-2010年数量与面积减少的特征；天然湖泊与人工湖泊变化差异显著，天然湖泊数量与面积均呈先增加后减少的变化特征，而人工湖泊数量及面积均呈持续增加的变化特征；1975-2000年各流域湖泊面积均增大，2000-2010年除伊犁河内流区外，各流域湖泊面积均大幅度减小；影响新疆干旱区湖泊变化的主要气候因素是降水与气温，人类活动是流域间湖泊变化幅度与变化趋势差异的主要影响因素，也是影响天然湖泊与人工湖泊变化趋势差异的主要原因。

Lake change research and reasons analysis in Xinjiang arid regions during the past 35 years

Xinjiang is located in the hinterland of arid areas in the northwest China. Due to the hot summer and low precipitation，water shortage is an extremely serious problem in the region. Lake as an important water carrier in the arid region maintains the balance of the fragile eco-system and plays a vital role in the social-economic development. Therefore，the lake changes and the driving factors were widely concerned. By using “3S” （RS，GIS，GPS）technology and based on the research unit of catchment，this study investigated the changes of the lakes in the region over the period from 1975 to 2010. The paper selected MSS data in 1975，ETM data in 2000 and TM data in 2010 and extracted information of a single lake with an area greater than 0.25 km2 by using man-computer interactive interpretation method. The results showed that there were a large number of lakes distributed over the region but most of them were small scale lakes. The natural lakes were the dominant in the region. The Junggar Endorheic System had the largest lake area while the Tarim Endorheic System had the largest number of lakes. Overall，the number of the lakes and the area of the lakes both increased in the period from 1975 to 2000 and then both decreased in the next 10 years to 2010. There was an obvious difference between the natural lakes and the artificial lakes on the numbers and the areas. The number and the area of the artificial lakes in the region both kept increase over the study period which was different with the natural lakes. The lake areas increased in all catchments in Xinjiang from 1975 to 2000. However，the lake areas significantly decreased except the lakes in Ili River catchment. The precipitation and the temperature were the main climatic factors impacting the changes of the lakes. Human activities significantly influenced the changes and the trends of the lakes，which caused the differentiation in the lake changes between the natural and the artificial lakes. This study provided theoretical support to the water resources management and utilization on catchment unit.