Analysis of Water Chemistry Characteristics and Main Ion Controlling Factors of Lakes in the Nagqu Area of the Qinghai–Tibet Plateau in Summer

The Nagqu area is in the northern part of Qinghai–Tibet Plateau, and its average altitude above 4000 m. Due to area’s high altitude, there relatively little information about lakes. Therefore, supplement basic lakes area, this study collected surface water samples from 12 lakes, including Gangtang Co, Pusaier Guojialin Dagze Yangnapeng Bankog Dangqung Chaxiabu Angdar Bengze Guogen Yibug Caka July August 2020. Furthermore, factors controlling lake chemistry characteristics main ion sources were explored using Piper, Gibbs, ratio methods. results as follows: (1) had levels salt, alkalinity, mineralization, all except Co salt met Class V standard. (2) Daze initial stage succession, while others later stages succession. (3) Evaporation–crystallization was most important factor ions come dissolution evaporite.