Hydrochemical Characteristics and Controlling Factors of the Mingyong River Water of the Meili Snow Mountains, China

The hydrochemical characteristics of rivers are affected by many natural factors, such as the nature of watershed bedrock, watershed environment, vegetation, and human activities. Examining the hydrochemistry of a river can provide insights into the baseline hydrological conditions, the geochemical environment, and the overall water quality of the river. In order to examine the hydrochemical characteristics and controlling factors of the water in the Mingyong River, a total of 154 water samples were gathered from the glacier meltwater, midstream, and downstream regions. Firstly, the findings revealed that the dominant cations are Ca 2+ and Mg 2+ , while the dominant anions are HCO 3 − and SO 4 2− . The mass concentration order of cations is Ca 2+ > Mg 2+ > Na + > K + , and for anions, it is HCO 3 − > SO 4 2− > NO 3 − > Cl − . The average concentration of TDS in the river water is 81.69 mg·L −1 , with an average EC of 163.63 μs·cm −1 and an average pH of 8.99. Temporal variations in ion concentrations exhibit significant disparities between the glacier melting and accumulation periods. High ion concentration values are primarily observed during the glacier accumulation period, while values decrease during the glacier melting period due to increased precipitation. The river water in the study region is categorized as (HCO 3 − + SO 4 2− )-(Ca 2+ + Mg 2+ ) type. Secondly, the Pearson correlation analysis indicates clear relationships between different parameters, indicating that the major ions were mostly influenced by materials from the Earth’s crust. The primary principal source of solutes in the water of the Mingyong River is rock weathering. The cations and anions present in the river water are derived from the breakdown of carbonate rocks and the dissolving of substances from silicate rocks. However, the influence of carbonate rocks is more significant compared to that of silicate rocks. Finally, the Mingyong River water is suitable for agricultural irrigation with minimal land salinization damage, making it appropriate for agricultural purposes but not suitable for people and animals to drink from directly.