Investigation of bathymetry and water quality of Lake Nam Co, the largest lake on the central Tibetan Plateau, China |
| |
Authors: | Junbo Wang Liping Zhu Gerhard Daut Jianting Ju Xiao Lin Yong Wang Xiaolin Zhen |
| |
Institution: | 1. Institute of Tibetan Plateau Research, Laboratory of Tibetan Environment Changes and Land Surface Processes, Chinese Academy of Sciences, No. 18 Shuangqing Road, Haidian District, 100085, Beijing, People’s Republic of China 2. Institut für Geographie, Friedrich-Schiller-Universit?t, Jena, Germany 3. Science in China Press, 100717, Beijing, People’s Republic of China
|
| |
Abstract: | Comprehensive field investigations have been conducted four times on Nam Co, central Tibet, from September 2005 to September
2008. Here, we present the preliminary results focusing on the bathymetric survey and water quality measurements. The isobathic
map shows that Nam Co is a high-altitude, deep lake where a flat and large basin lies in the central part with a water depth
of more than 90 m. Water depth data from the northwestern bank areas of Nam Co provide unquestionable evidence of rising water
levels in the last 3 decades because of the formation of two small islands that were still peninsulas in the 1970s. Water
quality measurements taken at 19 stations during three summer field campaigns (2006, 2007 and 2008) covering almost all of
the lake areas showed that the temperature, pH, dissolved oxygen and electric conductivity of surface water are on average
11.43°C, 9.21, 8.90 mg l−1 and 1,851 μS cm−1, respectively. The surface water shows no obvious spatial variability among all the stations. Vertical fluctuations of profiles,
however, display some differences in thermocline and related parameters, such as pH and dissolved oxygen. According to the
vertical variations of water quality parameters, the water column in relatively deep lake areas of Nam Co could be divided
into three layers with distinctly various features: the epilimnion is from the surface to about 18–20 m depth in which the
parameters are homogeneous with higher temperature and abundant sunlight; the metalimnion ranged from 20–60 m where a thermocline
develops; the deepest layer forms a cold and dark hypolimnion. |
| |
Keywords: | Bathymetric survey Water level rising Water quality Thermocline Nam Co Tibetan Plateau |
本文献已被 SpringerLink 等数据库收录! |
|