Investigation and Analysis of the Water Environment Status of Qinghai Lake and Its Surrounding Wetlands

Abstract

Abstract:Qinghai Lake is the largest inland saltwater lake in China and also an important ecological security barrier in the northeastern Qinghai-Tibet Plateau. To reveal the characteristics of its water environment changes, this study set up sampling points in typical areas including the main lake area, estuary areas and surrounding sub-lakes of Qinghai Lake during the dry season (May) and wet season (August-September) in 2019 and 2024, respectively, to carry out synchronous collection and monitoring analysis of water quality samples, compare the differences of water environment in different periods and regions, and explore the input sources and influencing factors of nitrogen and phosphorus nutrients. The results showed that the physical and chemical conditions of the main lake area of Qinghai Lake were generally excellent, with indicators showing significant seasonal differentiation and the overall nutritional level being low. However, the total nitrogen content showed an increasing trend, and the problem of continuous input of nitrogen and phosphorus in the basin became prominent. The concentrations of nitrogen and phosphorus in the in-flowing rivers, surrounding sub-lakes and wetlands were generally higher than those in the main lake area, which were the main input sources of nitrogen and phosphorus nutrients in Qinghai Lake. The concentrations of nitrogen and phosphorus presented obvious seasonal characteristics: total phosphorus was higher in the dry season and total nitrogen was higher in the wet season, and their contents were affected by multiple factors such as surface runoff, human activities and biological activities. The results of this study can provide basic data and theoretical support for ecological protection, nitrogen and phosphorus pollution prevention and control, and scientific water resources management in the Qinghai Lake basin.