10 years of in-situ water quality parameters of the lakes on the Tibetan Plateau Published
Recently, Prof. ZHU Liping (corresponding author) and doctoral student LIU Chong (first author) at the Institute of Tibetan Plateau Research, Chinese Academy of Sciences, published an article entitled "In-situ water quality investigation of the lakes on the Tibetan Plateau" in Science Bulletin. The corresponding dataset, "In-situ water quality parameters of the lakes on the Tibetan Plateau (2009-2020) ", has been published on the National Tibetan Plateau/Third Pole Environment Data Center (http://data.tpdc.ac.cn/en/).
The lakes on the Tibetan Plateau account for 57% of the total lake area in China, which is a key component of the Asia water tower. There are 1424 lakes greater than 1 km2 on the TP, while the total lake area reached 5.0 × 104 ± 791.4 km2 in 2018. Most lakes on the TP are closed and are less disturbed by human activities than the other inland water bodies in China. Therefore, the lake water’s hydrochemical characteristics, through the influence of water profile thermal distribution, energy exchange with surface air moisture, and lake ecological conditions, are sensitive to climatic and environmental changes in the area. Due to the harsh environmental conditions of most lakes on the TP, the lack of actual measurement data of lake water quality parameters has seriously restricted the in-depth understanding of the spatial and temporal changes of lakes on the TP. This study, based on the hard investigation work over the past 10 years, provides the in-situ lake water parameters of 124 closed lakes, collected from 2009 to 2019, with a total lake area of 24,570 km2, occupying 53% of the total lake area of the TP. These in-situ water quality parameters include water temperature, salinity, pH, chlorophyll-a concentration, blue-green algae (BGA) concentration, turbidity, dissolved oxygen (DO), fluorescent dissolved organic matter (fDOM), and water clarity of Secchi Depth (SD).
Fig. 1. Spatial and numerical distribution of lake water quality parameters, including salinity (a1, b1), pH (a2, b2), water temperature (a3, b3), chlorophyll-a concentration (a4, b4), blue-green algae (BGA) concentration (a5, b5), fluorescent dissolved organic matter (fDOM) (a6, b6), turbidity (a7, b7), dissolved oxygen (DO) (a8, b8), and clarity of Secchi Depth (SD) (a9, b9). Histograms display the count of lakes in parameter gradients. Box plots display the average and median (solid point and vertical line in the box interior, respectively), distance between the 25th and 75th percentiles (box limits), and standard deviations (SD, whiskers). Hollow points indicate outliers (with values outside of standard deviation).
This research showed that the TP lake salinity varied widely from freshwater to salt lake water, and the majority are not freshwater at present. Most of the lakes showed an alkaline status, low eutrophication, low concentrations of phytoplankton and fDOM, low turbidity, and high clarity. Lake salinity and pH show obvious north-south differences, lake water temperature shows seasonal and altitude-dependent variations, while lake water transparency deepens with increasing lake area. This study first puts forward the measured water quality parameters of large-scale lakes on the TP, which provides rich basic data for the study of scale transformation and spatial and temporal changes of lake water environment parameters. This will promote further understanding of the regional water environment, aquatic ecology, and water resources during climatic changes on the TP, and help to understand the characteristics of water bodies throughout China.
This work was supported by the Strategic Priority Research Program of Chinese Academy of Sciences (XDA19020303), the National Natural Science Foundation of China (41831177), the Second Tibetan Plateau Scientific Expedition and Research (2019QZKK0202).
Liu,C., Zhu, L.P., Wang, J.B., Ju, J.T., Ma, Q.F., Qiao, B.J., Wang, Y., Xu, T., Chen, H., Kou, Q.Q., Zhang, R., & Kai, J.L. (2021). In-situ water quality investigation of the lakes on the Tibetan Plateau, Science Bulletin, ISSN2095-9273, https://doi.org/10.1016/j.scib.2021.04.024.
Data available at:
Reprinted from the website of the Institute of Tibetan Plateau Research, Chinese Academy of Sciences