Study on the Spatial and Temporal Pattern of Qinghai Lake Area in the Past 50 Years

Lakes are not only the essential water resources for life, but also the sensitive indicators of climate change. The change of Lake area has a direct impact on the regulation of ecological environment. The area changes of shoreline were analyzed by using Multi-source Satellite Data and water identification model of Qinghai Lake in the past 50 years, the main conclusions are as follows: (1) The monitoring accuracy of Qinghai Lake area can significantly be improved by using multi-source high satellite data; (2) The experience threshold model based on the combination multi band with single band has a higher recognition accuracy of water when monitoring the area of the Qinghai Lake; (3) In recent 50 years, although the Qinghai Lake area of the stage showed an decreasing trend, since the beginning of twenty-first Century, the Qinghai Lake area increased, especially significantly in 2010, the Qinghai Lake area has been close to in 1995. But overall, still showed a decreasing trend; The analysis of area change in dry and wet season showed that the Qinghai Lake area were increased (R2 = 0.805 and 0.861, P < 0.01) in April and September from 2001 to 2015, since 2005, increasing trend is more obvious; What it is clear changes by the use of environmental mitigation satellite data in Qinghai Tibet Plateau the changes can be used to fine the monitoring area of Qinghai Lake monthly and seasonal occasion. (4) In the past 50 years, Qinghai Lake shoreline change has a large difference between North and south. Qinghai Lake on the west coast of Shi Nai Hai - Heather skin, Quanji river north of Hukou near the east coast of Salix River into the lake and the island Haiyan Bay, lake shoreline retreat is most obvious.