[Water Environmental Characteristics and Water Quality Assessment of Lakes in Tibetan Plateau].

ABSTRACT

Lakes are an important water resource and biological habitat in the Tibetan Plateau. Owing to the combined influence of climate, topography, and other natural factors as well as human factors, the water environment of the lakes on the Tibetan Plateau is facing more and more severe problems and challenges. To clarify the present status, distribution pattern, main characteristic factors of water quality, and important factors affecting the water quality of lakes on the Tibetan Plateau, the water environment of 12 typical lakes on the Tibet Plateau was investigated in summer (July-August) and autumn (October-November) in 2020. The field sampling and laboratory test data comprehensive analysis showed that① several physical and chemical parameters of typical lakes on the Tibetan Plateau differed in spatiotemporal distribution. ② Salinity was the main characteristic of water quality in the typical lakes on the Tibetan Plateau. ③ The spatiotemporal distribution of lake eutrophication index showed little diversity and basically ranged from poor nutrition to moderate nutrition. The spatial and temporal distributions in the lake water quality index (WQI) were significantly different. The lake WQI grade decreased from "Moderate" to "Very poor" with the increase in salinity area, and the lake water quality in autumn was better than that in summer. ④ The spatiotemporal differences in lake water quality on the Tibetan Plateau were mainly controlled by precipitation, evapoconcentration, and human activities. This study will provide scientific basis for water environment protection and improvement of water ecosystems on the Tibetan Plateau.