【摘要】 近年来,由于气候条件的变化,青海湖水位呈下降趋势,水域面积逐年缩小。选用1986年至2005 年的美国Landsat-5卫星图像数据对青海湖地区进行长达20年的跟踪监测研究结果表明,2004年青海湖水域面积比1986年缩小了约80 km2,与1989年相比,水域面积缩小了129 km2;水域面积最大和最小的年份分别是 1989年和2001年,面积相差135 km2。在过去20年间,青海湖水域面积的变化有2个明显的特征,第一,整体上呈现出十分明显的下降趋势;第二,年度变化呈现了在整体下降的同时又有短期小幅回升的现象,回升时间不超过2年。湖岸线年度变化遥感监测资料表明,青海湖湖岸线的年度推进量在40-200 m之间。在与青海省及湖区同期气象资料的分析对比后发现,湖区水域面积与地表蒸发量、气温以及地表温度的年度变化呈负相关, 且变化的趋势有较好的一致性。更多还原

【Abstract】 The water level of Qinghai Lake descends and its water area reduces in recent years owing to the climate changing. In this paper, the remote sensing methods and Landsat - 5 image data from 1986 to 2005 were used for monitoring study on Qinghai Lake. It shows that, the water area in 2004 reduced about 80 km2 than that in 1986 and 129 km2 than that in 1989. The maximum and minimum water area appeared in 1989 and 2001 respectively, and the difference between them is 135 km . Studies show that there are two apparent features in the annual changing of the water area of Qinghai Lake: (1)The water level shows an obvious descending tendency in the last 20 years. (2)The annual changing of water level shows a decline on the whole and at the same time shows a small amplitude of ascending during a short period which is less than 2 years. Remote sensing studies also show that the annual lakeshore changing of Qinghai Lake is about 40 m to 200 m. Analysis on the climate data of the same time shows that there is a negative relation between the water area of the lake and the changes of the surface evaporating amount, temperature and surface temperature and their changing tendencies have a better coincidence.更多还原