By Source:China Tibet Online
2015-07-23
As a result of rising temperatures, the number of days with snowfall recorded by weather stations in Tibet between 1981 and 2014 has decreased, Chinatibetnews.com reported.
On average it has decreased by 4.7 days per year. The annual maximum snow depth has also followed this decreasing trend with an average drop of 0.47cm.
The Qinghai-Tibet Plateau is the source of some of Asia’s most famous rivers, including the Yangtze, Yellow, Yarlung Tsangpo, Lancang (Mekong), Indus, and Ganges rivers. It is known as “Asia’s Water Tower” because the water from these rivers helps maintain the livelihoods of hundreds of millions of people on the plateau and in the further downstream. As a result, the monitoring and protection of its water resources is of utmost importance.
Snow cover on the Qinghai-Tibet Plateau is also important for maintaining the ecological environment as it provides the rivers’ runoff with a natural delay and annual redistribution. Any change in this dynamic can directly affect the water resources of the plateau and downstream areas. Therefore, plateau monitoring and research was introduced, which not only plays an important role in the protection and use of the world’s unique water resources, but also has particular significance in relation to changes in the plateau’s ecological environment, handling climate change and the construction of ecological civilization.
Tibet Autonomous Region Weather Bureau’s remote sensing and monitoring data indicates that, from 2001 to 2014, average snow cover on the plateau was 190,000 square kilometers, accounting for 15.8 percent of the entire plateau. In the past 15 years, the average annual variation in snow cover showed a slight decrease. The seasonal variation showed that snow cover in autumn and winter was slightly on the rise; there was a slight decrease during spring; and the most noticeable decrease during summer.
Satellite remote sensing data from 2014 showed that snow covered 176,000 square kilometers of the plateau on average, 1.4 square kilometers smaller than the multi-year average.
