青藏高原湖泊变化遥感监测及其对气候变化的响应研究进展

青藏高原位于中国西南部、亚洲中部,平均海拔高程大于4000 m,面积约300万km²,是“世界屋脊”,与周边地区一起常被称为地球的“第三极”。青藏高原分布着约1200个面积大于1 km²的湖泊,占中国湖泊数量与面积的一半;同时也是黄河、长江、恒河、印度河等大河的源头,被称为“亚洲水塔”。近几十年来,在全球变暖的背景下,青藏高原升温更加突出,其能量与水循环发生了显著变化,气候趋于暖湿化,冰川加速消融,湖面水位上升。湖泊是气候变化的重要指标,青藏高原湖泊分布密集、人为活动影响较小,多源遥感数据的广泛应用,为监测高原湖泊变化提供了难得的契机。本文依托国家自然科学基金青年项目“基于多源遥感的青藏高原内流区湖泊水量变化及水体相态转换研究(2000-2009年)”,主要研究进展为：初步查明了西藏高原的湖泊数量、面积及水位变化与时空格局,以及湖泊水量变化与水量平衡;探讨了湖泊变化对气候变化的响应。目前对青藏高原湖泊的变化及驱动因素虽有一些认识,但其定量的水量平衡及驱动机制还有待于进一步研究。这对了解世界第三极、一带一路国家和地区水资源状况与变化、生态文明和生态安全屏障建设具有重要的意义,同时也可为第三极国家公园的建立提供重要的科学基础。

Changes in lakes on the Tibetan Plateau observed from satellite data and their responses to climate variations

The Tibetan Plateau (TP) is located in the southwest of China and central Asia, with a mean elevation higher than 4000 m and area of 3×10⁶ km². It is named "the roof of the world". The TP and surrounding areas together is also called "the Third Pole". The TP has 1200 lakes greater than 1 km² in area, which accounts for approximately 50% of the total number and area of lakes in China. It is the sources of the Yellow River, the Yangtze River, the Indus, Ganges, Brahmaputra, Irrawaddy, Salween, and the Mekong, and therefor known as "Asia's water tower". In the past several decades, the TP experienced a faster warming than other regions in the world. The climate of the TP is also getting wetting. Lakes are indicators of climate change. The TP has the dense distribution of lakes with little disturbance of human activities. The utilization of multi-sensors’ data has provided a useful tool to monitor lake change in the remote TP. Several studies of lake changes have been conducted focusing on the following scientific questions: (1) how many lakes are on the TP and what are the spatial and temporal changes of the number, area, and abundance of these lakes? (2) the increased mass over the TP from glaciers or lakes? (3) under anthropogenic warming, how did the water and cryosphere cycles change on the two adjacent largest Plateaus in the world, the Tibetan and the Mongolian Plateaus, over the last four decades? and (4) how did the lake water storage and water balance change? These studies are of great significance to the understanding of the third pole of the world, the state of regional water resources and changes, and ecological civilization and ecological security construction. They also provide an important scientific basis for the planning of the third polar national park. The quantitative understanding of lake water balance and mechanisms and driving factors of lake change needs further work in the future.