【作者】 张鑫；

【导师】 张鑫；

【作者基本信息】 西北农林科技大学 ， 水文学及水资源， 2015， 硕士

【摘要】 湖泊作为自然界的特殊单元,它的形成与消失、扩张与收缩,以及其引起的变化,能真实的反映气候与环境的变化情况,是全球气候变化的指示器。而青藏高原被誉为“世界屋脊”,有“亚洲水塔”和“第三极”之称,其环境变化对全球变化具有敏感效应与强烈影响。青藏高原具有世界上数据量最多、海拔最高的高原湖群,这些湖泊大部分处于自然状态下,极少受人为扰动,因此青藏高原的湖泊面积、水位变化能够清晰的记录湖泊波动,这些波动与气候变化和冰川退缩之间存在着紧密的内在联系,所以分析近几十年来气候变暖背景下青藏高原典型湖泊动态变化,对理解全球变化的区域响应特征和规律有重要意义。而湖泊的变化主要受制于气象条件,如降水、蒸发、气温等等,以及河流自身的补给方式,它们之间的相互作用,共同影响湖泊,使湖面缩小与扩张。湖泊的变化对气候变化有敏感响应,不同气候区,响应的程度和变化特征存在差异。若要探索影响湖泊动态变化的原因,须从气候变化方面入手。但青藏高原人烟稀少,气象站点分布稀疏,有些湖泊还未设立监测站点,但卫星遥感技术的快速发展为该地区的研究提供了强有力的支持,可通过遥感手段解译青藏高原典型湖泊的动态变化,并分析湖泊变化与气候变化的响应机制。本文以纳木错流域、扎日南木错流域、塔若错流域、普莫雍错流域、玛旁雍错流域、佩枯错流域六个青藏高原中南部典型湖泊所在的流域为研究对象,利用多种遥感数据源,以获取研究区内1972-2012年湖泊的面积与水位序列,并分析湖泊面积、水位的变化特征。为了进一步分析影响湖泊变化的原因,本文还利用SEBS模型模拟了青藏高原2001-2010年的蒸散发变化,结合气温、降水数据,试从水量平衡的角度解释湖泊的动态变化。论文的主要研究成果和结论如下:(1)1972-2012年间,纳木错、普莫雍错、扎日南木错、塔若错的面积分别扩张了80.68 km2、6.62 km2、36.97km2、3.63 km2,玛旁雍错、佩枯错的面积缩小了5.36km2,9.46km2;纳木错与普莫雍错的面积在整个研究时段都呈增长趋势,玛旁雍错与佩枯错的面积呈现持续下降的趋势,而扎日南木错与塔若错的面积呈先减少后增加的变化趋势;研究还表明,2000年后湖泊的面积变化比2000年之前更剧烈。(2)研究区内湖泊的水位变化如下:纳木错(1995-2010)、普莫雍错(2003-2014)、扎日南木错(1992-2012)、塔若错(2003-2014)、玛旁雍错(2002-2010)、佩枯错(2003-2008)的水位的变化速率分别为0.274m/a、-0.011m/a、0.039m/a、0.089m/a、-0.135m/a,-0.169m/a;(3)1972-2012间,研究区各流域呈现出明显的升温趋势;纳木错流域、扎日南木错流域以及塔若错流域的降雨量呈上升趋势,而普莫雍错流域、玛旁雍错流域与佩枯错流域内的降水量呈下降趋势;2001-2010年间纳木错流域、普莫雍错流域、玛旁雍错流域以及佩枯错流域的蒸发量呈上升趋势,而扎日南木错流域、塔若错流域的蒸发量呈下降趋势。(4)由于补给方式主要是冻土与冰雪融水形成的径流,纳木错流域、普莫雍错流域的降水量与蒸发量都呈上升趋势,面积与水位持续上升;受湖面降水补给的扎日南木错流域与塔若错流域,降雨量呈上升趋势,蒸发量呈下降趋势,可能导致湖泊水位与面积上升;而位于边缘地带的玛旁雍错流域与塔若错流域,蒸发量与降水量呈下降趋势,冰雪融水等的河流补给较少可能是导致流域内湖泊水位与面积降低的原因。更多还原

【Abstract】 The lake, the special element of nature, is called the indicator of the global climate changes, and its expanding,contracting and disappearing can truly reflect the climate and environmental changes. Tibetan Plateau(TP), known as the ―Water Tower of Asia‖ and ―The Third Pole,‖ is highly relevant to global climate dynamics changes. TP has the largest number of alpine lakes in the world in nature state which have no influence of artificial disturbance, therefore, the changes of those lake and area levels could keep a clear record of lake variation in TP. Those variations are internal connected with climate changes and glacier retreat. To reveal the dynamic lake variation of the inland lake in TP, we would facilitate understanding of regional responses to climate changes under global warming in recent decades.The changes of lakes are mainly influenced by meteorological conditions, such as precipitation, evapotranspiration,temperature, and recharge types of basin. The different climate zones could cause the various changes of lakes. The meteorological station are of scarcity and uneven distribution in TP, and some lakes even have no stations. Rapidly development of remote sensing technologies provide powerful support for the research on TP, which opens a good way to further understanding the processes and extent of lake s and its response to global climate changes.This paper focuses six basins, Namco basin, Zhari Namco basin, Taro Co basin, Pumo Yumco basin, Mapang Yumco basin and Peiku Basin, which are all situated in south-central of TP, multi-source remote sensing data and products are sufficiently exploited to obtain the time- series of the six typical lakes area and level from 1972 to 2012, and analyzed the variation in recent 40 years. In addition, This paper also simulated TP evapotranspiration by SEBS from 2001 to 2010. The evapotranspiration results, combined with temperature and precipitation, are used to explain the dynamics changes from the aspect of water balance,and discuss the hydrologic environment changes and their relationship with climate changes. The main results are follows:(1) From 1972 to 2012, the four inland lakes(Namco, Pumo Yumco, Zhari Namco, Taro Co) have expanded by 80.68 km2、6.62 km2、36.97km2、3.63 km2 in lake area, respectively,while the two lakes(Mapang Yumco, Peiku Co,) have contracted by 5.36km2,9.46km2, On the whole, the lakes area of Namco and Pumo Yumco present increasing tendency, Mapang Yumco and Peiku Co decreasing, while the lakes area of Zhari Namco and Taro Co are decreased gradually and then increased;(2) In 1972-2012, The lake level change ratio of Namco(1995-2010), Pumo Yumco(2003-2014), Zhari Namco(1992-2014), Taro Co(2003-2014), Mapang Yumco(2002-2010), Peiku Co(2003-2008) are 0.274m/a、-0.011m/a、0.039m/a、0.089m/a、-0.135m/a,-0.169m/a, respectively;(3) In 40 years, the trend of temperature in each basin is remarkably increased; the trend of precipitation in Namco basin, Zhari Namco basin and Taro Co basin are increased, while Pumo Yumco basin, Peiku Co basin and Mapang Yumco basin are decreased, In 2001-2010, the evapotranspiration of Namco basin, Pumo Yumco basin,Peiku Co basin and Mapang Yumco basin went up, while Zhari Namco basin and Taro Co basin went down;(4) Because the discharge is mainly from the runoff formed by snow meltwater and permafrost, the rainfall and evapotranspiration of Namco basin, Pumo Yumco basin has grown, the same as the lake level and area; while the Zhari Namco basin and Taro Co basin are discharged by rainfall, the lake level and area are grown up; The main reason of Peiku Co basin and Mapang Yumco basin, located in south fringe of TP, may be the fewer discharge and rainfall, with the evapotranspiration increased更多还原