中文摘要：

青海是中国盐湖主要分布区之一,蕴藏着丰富的矿产资源。文章以RS和GIS技术为基础,从20世纪70年代、90年代、2000年前后、2008-2009年和2013-2014年五期Landsat遥感影像中提取了青海面积大于10 km2的所有盐湖（不包括干盐湖）,分析了其近40年来的变化趋势：总体上,盐湖总面积除在2000年前后有所减少外,基本上呈现增加的趋势;具体而言,2000年前后,萎缩的盐湖主要分布在柴达木盆地;其他时期均呈现全面扩张的趋势。在全球气候变暖的大背景下,通过分析青海地区11个气象台站的年平均气温、年降雨量和蒸发量数据,可知青海地区气候呈现了向暖湿方向转型的趋势,且2002年之后更为明显。最后,以青海省小柴旦湖为例,分析了湖泊淡化、矿产资源贫化对盐湖资源开发的影响,具体为：1资源开发成本升高、难度加大,甚至使一些处于工业开发临界品位的盐湖失去开发价值;2盐湖淡化条件下,锂等矿产资源有效提取技术亟待研发;3政府制定矿产资源开发政策时,需要对气候及盐湖的动态变化过程综合考虑。以上说明,青海地区的暖湿气候使盐湖大幅度淡化,给盐湖矿产资源开发带来了新的挑战。

英文摘要：

Qinghai is the main area with extensive distribution of salt lakes which are rich in mineral resources. The authors extracted information of all salt lakes each of which has an area larger than 10 km2 （excluding dry salt lakes） in Qinghai from Landsat of five periods, i.e. and from 2013 to 2014, based on RS and GIS, and the 1970＇ s, the 1990＇ s, around 2000, from 2008 to 2009 then analyzed dynamic changes of these salt lakes. On the whole, the total area of these salt lakes increased except in the period around 2000; more specifically, in the period around 2000, salt lakes whose areas decreased were mainly distributed in the Qaidam Basin, whereas in all other periods salt lakes tended to expand. In the background of the global climate warming, the authors analyzed annual mean temperature, annual rainfall and annual evaporation data from 11 meteorological stations of Qinghai, and have reached some conclusions based on the data obtained： in the past forty years, the climate in Qinghai has tended to change into warm wet, especially since 2002. Finally, with the Xiao Qaidam Lake as an example, the influence of lake desalination and mineral resources impoverishment on mineral resources exploitation was analyzed： （1） it has caused higher cost and more difficulties, even some salt lakes at the critical-grade level for industrial development will lose their exploitation value; （2） under the condition of salt lake desalination, effective extraction technologies of mineral resources such as lithium require development urgently; （3） such a situation may have some impact on the government＇ s policy-decision for mineral resources development, and the establishment of the pre-warning and monitoring system of salt lakes in Qinghai is necessary. Remote sensing with its unique advantages is effective in the investigation and evaluation of salt lake resources in Qinghai under the conditions of bad traffic, fragile ecological environment and high cost of surveying.