1976-2009年青藏高原内陆湖泊变化的时空格局与过程

为了揭示近几十年来气候变化条件下青藏高原内陆现代湖泊的时空变化规律，在1976年、1990年、2000年和 2009年4个时段青藏高原内陆湖泊变化制图结果的基础上，重点分析流域内湖泊变化的时间过程和流域间湖泊变化的空间模式，并从气候要素变化、流域水源补给等方面探讨影响内陆湖泊变化的主要因素。结果表明：流域内湖泊总面积1970-1990年萎缩、1990-2009年扩张，1976-2009年呈现扩张的变化趋势，年均降水量和年均气温的变化趋势较好地解释了湖泊由萎缩到扩张的变化状况。从湖泊变化的空间格局来看，不同地域、不同流域的湖泊面积变化模式及其剧烈程度与流域内的水源补给方式有关，以雪冰融水补给的流域内湖泊总面积变化的剧烈程度远不及以冻融水补给为主的流域。因此，区域气候的变化是近几十年来高原内陆湖泊整体显著萎缩或扩张的主要原因，而流域水源补给的方式诠释了湖泊变化的区域差异。

Spatiotemporal Pattern and Process of Inland Lake Change in the Qinghai-Tibetan Plateau during the Period of 1976-2009

In this paper, the dynamic variation of the inland lakes in the Qinghai-Tibetan Plateau was investigated based on the mapping of the lakes in 4 years (1976, 1990, 2000 and 2009) and the Landsat time series images so as to reveal the spatiotemporal variation of the lakes in the plateau under climate change in recent decades. The temporal processes and spatial patterns of change of the lakes were analyzed at drainage basin scale, and the mechanism of inland lake change was discussed from the aspects of regional climate factors and recharge water sources of the lakes. The results showed that the inland lakes in the plateau were holistically in a shrinkage during the period of 1976-1990 but in an expansion during the period of 1990-2009, and the total lake area was expanded by 27.3% during the period of 1976-2009. Considering from the spatial patterns of lake change, the lakes recharged by groundwater were in a dramatic expansion or shrinkage, but those recharged by glacial melt water were stable or in a slight expansion. Recharge water sources of the endorheic basins affected strongly the lake change rate, the change of climate factors, such as precipitation, evaporation and air temperature, could be used to explain the shrinkage or expansion of the lakes. Therefore, regional climate change is the key factor causing the dramatic change of the inland lakes in the Qinghai-Tibetan plateau, and the recharge water sources could be regarded as the main factor affecting the regional difference of lake change.