Remote Sensing Study Of Qinghai Hoh Xil Lakes Change

Global warming is an observed increase in the average temperature of the Earth′satmosphere and oceans . Such a climate chang would most likely affect the lakesand wetlands through its effect on water levels in the lakes and ground—water systemfeeding the lakes . As a unique geographic body of the Earth ,Tibetan Plateau lakesecosystems may be sensitive indicators of climatic warming trends.To investigate thechanging, find the mechanisms of this control and its long—term dynamics , thesatellite remote sensing technology for monitoring the lakes of Tibetan Plateau isproposed.Satellite remote sensing has become as a powerful tool for earth scientists invarious invetigations. Remote sensing imagery provides converge of large areas withquantitative observational parameters such as spectual radiance and is thus apotentially rich data source for monitoring the changing lakes of Tibetan Plateau.Although there a few dozens of remote sensing satellite series in operations e.g.IKONOS, QUICKBIRD, SPOT, and LANDSAT etc.,it is not all suitable formonitoring the lakes changing of Tibetan Plateau . In this project ,the MSS data of late1970s and ETM data of afer 2000 are selectded depends on converges, resolution ,availability and the cost . LandSat satellite images are the only record of globalland—surface conditions for three decades at the appropriate resolution formonitoring the lake′s changes .As the pilot project of "Monitoring the changing lakes of Tibetan Plateau", thelakes in Hoh Xil region are investigated by the proposed methods . The Hoh Xilregion is located in the heartland of the Tibetan Plateau ,with an average altitude ofabout 5000m a.s.l., the Hoh Xil region is one of the higest regions of TibetanPlateau . The most part of this region has suffered little human impact. A large numberof lakes are extensively distributed in it , with a total area of about 3825 and a lakedegree about 0.05. There are also many kinds of lakes . Based on collecting MSSimages of 1970′s and TM/ETM images of 2000′s ,selected 35 lakes of more than10k ㎡ . Analyzed the affecting of the climate, glaciers, geomorphology to thechanging of lakes in the region ,we get many meaningful conclusions as follow: Inthe Northern and in the heartland of the Hoh Xil region ,the most lakes areshrinking ,especially the lakes that less water supply. In the Southern ,the area of lakesbecome larger or change little .The main reason maybe : the glaciers around theselakes are melting and water pouring into the lakes. The conclusion demonstrates thatthe changes we are seeing in Hoh Xil lakes in response to the warming climate arealso occurring in the whole Tibetan Plateau.