Remote Sensing Image's Interpretation Of Changes In The Qinghai-Tibet Plateau's Overlarge Lakes And Its Environmental Significance

Qinghai-Tibet Plateau has the complex geological features and many lakes with a vast territory. Lake is a product of uplift of the Qinghai-Tibet Plateau, the lake's development and evolution is important evidence of the Tibetan Plateau evolution of the geological environment. Qinghai Lake, Namuco and Selincuo are the three overlarge lakes located in the Tibetan Plateau. In the cause of different geological structure, glaciers, climate change and other environmental effects, this three large lakes'cause of formation , development, geomorphology, hydrology, biology and ecology exhibits different characteristics and types.In this paper, Qinghai Lake, Namuco and Selincuo which three large lakes are studied, mainly with the use of remote sensing data MSS and ETM of the Qinghai-Tibet Plateau, and based on the relevant information got from field investigations, combined with computer technology and remote sensing and geographic information systems technology and other methods. On the basis of the explore and identify the method and signs of interpretation of remote sensing images of the lake's changes in the Qinghai-Tibet Plateau, this paper analysis the characteristics and reasons of the three large lakes'changes , and then discusses the evolution of Qinghai-Tibet Plateau and the geological environment of its reflected.The main conclusion is as follows:1. Through numerous experiments, show that using principal component analysis and contrast expansion for the evolution of information extracting, will be more conducive to the identification and interpretation of the sediments, especially to extract lakeside's information achieved good results.2. The relevant features of Remote Sensing signs for the evolution of the lakes were to be established with the purpose of the study. These signs reflect the evolution of the lake directly, providing a scientific basis for the evolution of the lake.3. From several aspects, such as temperature and precipitation changes, inland rivers and outland river runoff changes, lake's changes of the drainage areas of the Tibetan Plateau in recent decades, to quantitative analysis the evolution of the three large lakes on the Qinghai-Tibet Plateau. Studies show that the water level of Qinghai Lake was declined, lakes area gradually become smaller, Namuco and Selincuo's situation just the opposite. A series of interactive characterizations happened in the lakes ecosystem correspondingly4. About climate change, in the 20th century's last 40 years, the Tibetan Plateau's average temperature rised, the existence of complex spatial variation of temperature in summer and winter are more obvious; the rate of temperature performance makes a notable change; the annual rainfall decline.5. Combined with the regional geological, tectonic setting, the ancient environment and ecological parameters of the three large lakes, and the geological environment evolutionary trend the lake since the late Pleistocene. Especially in the recent 30 years, the lake ecology geology environment evolution tendency, has in particular in the Qinghai-Tibet Plain different area, its regularity is obvious. Qinghai-Tibet Plain lake vicissitude is most remarkable in the Qiangtang area.6. Since the 1960s, the change of the climate, glaciers and other environmental factors in Qinghai-Tibet Plateau has obvious impact on the lake.