Title Hydrothermal processes of alpine tundra Lakes, Beiluhe Basin, Qinghai-Tibet Plateau
Author Lin Zhanju; Niu Fujun; Liu Hua; Lu Jiahao
Author Affil Lin Zhanju, Chinese Academy of Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, Lanzhou, China
Source Cold Regions Science and Technology, 65(3), p.446-455, . Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0165- 232X
Publication Date Mar. 2011
Notes In English. Based on Publisher- supplied data GeoRef Acc. No: 309953
Index Terms Alpine landscapes; alpine tundra; climate; hydrology; ice; ice cover; lakes; lake ice; limnology; melting; permafrost; permafrost hydrology; snow; solar radiation; taliks; temperature; tundra; China; Asia-- Tibetan Plateau; alpine environment; Asia; Beiluhe Basin; depth; Far East; hydrothermal conditions; lake-surface temperature; nearshore environment; terrestrial environment; Tibetan Plateau
Abstract Most of the alpine tundra lakes, of average size 8,500 m2, are widely spread in the Beiluhe Basin on the Qing-Tibet Plateau, where ice-rich permafrost exists. Approximately 70% of the lakes are elliptical in shape and 15% are elongated. About 80% of the lakes are unfrozen to the bottom throughout the year while a larger portion of it, about 60%, may be underlain by taliks that penetrate permafrost. The BLH-A Lake, a representative lake with 2-m deep water in the region, has been observed for about four years (from 2006 to 2009). Ice starts to cover on the lake-surface after mid-October, and its thickness increases to 60 to 70 cm by the end of cold season. The ice cover then starts to melt in later April and melts completely around mid-May. The lake-surface temperatures change sinusoidally with the air temperatures, but lagging about half a month. The water warms with the increase of the water depth, and the maximum annual temperature appears at depth of 1.5 m with a value of 14.3C on July 30, 2007. The lake- bottom temperatures are not isothermal at different depths for most time of a year. It may be related to the variable climate, little snow, and intensive solar radiation. The mean annual lake-bottom temperatures are about 5.5C in the deep pool with 2 m deep water and 4.3C in the shallow nearshore zone with 1 m deep water. The warm lake-bottom causes considerable disturbance to the permafrost. Surveyed data show that there is no permafrost under the lake when the mean annual lake-bottom temperature is over 5C.
URL http://hdl.handle.net/10.1016/j.coldregions.2010.10.013
Publication Type journal article
Record ID 65006899