中文摘要：

选取黄河源区1976-2014年Landsat系列卫星影像,解译了该区域1 km^2以上的42个湖泊水面.结果表明：除鄂陵湖外,扎陵湖和其他中小湖泊在过去的38 a间总体上存在稳定（1976-1994年）-萎缩（1994-2004年）-扩张（2004-2010年）-稳定（2010-2014年）四个阶段的变化过程,湖泊总面积2004年最小,2007年已经超过1976年.扎陵湖和鄂陵湖2004年面积仅较1994年萎缩了1.4%,萎缩幅度很小.2005年,扎陵湖水面已恢复到萎缩前的水平.鄂陵湖在2005年以后水位开始快速上升,2007年7月上升至海拔4 270 m以上,2008-2014年的平均水位达到海拔4 270.58 m,较1986-1999年的平均值（海拔4 268.25 m）上升了2.33 m,湖面较1994年扩张了30.0-45.2 km^2.中小湖泊面积1994-2004年从288.0 km^2萎缩到193.0 km^2,萎缩幅度33.0%,2004年是萎缩速度最快的一年,2005年即迎来了快速增长,这两年中小湖泊面积的年均变化率分别达到-14.5%·a^-1和32.9%·a^-1,变化速率远大于其他年份.1956-2014年的气候水文变化显示,58 a来研究区气温上升趋势显著,变化倾向率达到了0.32℃·（10a）-1.2003、2004和2005年蒸发能力、降水量、径流量开始依次显著增加,至2014年,平均较前分别偏多53.8 mm（6.9%）、57.4 mm（18.5%）和3.523×108m^3（52.7%）.湖泊面积对气候、水文变化以及人类活动的响应关系表明,作为特大型外流湖,扎陵湖、鄂陵湖受降水径流补给变化的影响相对较小,鄂陵湖2005年后的扩张是下游黄河源电站抬高水位所致.中小湖泊面积变化与降水、径流有密切的关系,近期扩张是由降水、径流显著增加引起.流域尺度上,气温上升、蒸发能力增强不是2005年以后湖泊扩张的直接原因.

英文摘要：

Based on the Landsat satellite imagines over the source regions of the YellowRiver from 1976 to2014,forty-two lakes,of which the area was larger than 1 km^2,have been interpreted. The results showed that Gyaring Lake and other forty medium and small lakes,except for the Eling Lake,wholly had appeared four changing processes： a steady stage（ 1976 to 1994）,a shrinking stage（ 1994 to 2004）,an expanding stage（ 2004 to 2010） and again a steady stage（ 2010 to 2014）,with a minimum in 2004 and a sharply expanding in2005; and in 2007 the area had exceeded that in 1976. Both the Gyaring Lake and the Eling Lake had shrunk by1. 4% with a smaller rate from 1994 to 2004. In 2005 the area of the Gyaring Lake had restored to that before the shrinking. The water level of the Eling Lake has risen rapidly after 2005,up to more than 4 270 m in July 2007.The average water level of the lake had reached 4 270. 58 m from 2008 to 2014,2. 33 m higher than the water level（ 4 268. 25 m） averaged from 1986 to 1999,with an expanded area of 30. 0 - 45. 2 km^2. The total area of the forty medium and small lakes had shrunk from 288. 0 km^2 to 193. 0 km^2,with a rate of 33. 0%,from 1994 to 2004,and a fastest shrinking year in 2004,followed by a rapidly expanding year in 2005. The annual mean changing rates of the lake area in the two years reached- 14. 5% ·a^-1and 32. 9% ·a^-1,which were the maximum rates among all the study years. Analyzing the meteorological and hydrological data of the study area from1956 to 2014 shows that air temperature had risen significantly during the 58 years,with an increasing rate of0. 32 ℃ ·（ 10a）- 1. Evaporation,precipitation and runoff had increased significantly since 2003,2004 and 2005 to 2014,respectively,with the increments of 53. 8 mm（ 6. 9%）,57. 4 mm（ 18. 5%） and 3. 523 × 108m3（ 52. 7%）. Analyzing the relations between lake area change and climate change,hydrology change and human activities indicates that there is relatively small effect of precipitation and runoff