Hydrochemical Characteristics Of Major Rivers In The Western Tianshan Mountains,Xinjiang

Xinjiang is located in the hinterland of the Eurasian continent.It has a vast territory and a complex and changeable climate.Most rivers come from mountainous areas.The geological structure and geographical environment are very different,and there is little rainfall.It is a typical inland arid area in China.The problem of water resources and water environment is a serious problem in the rapid development of society.Studying the stable isotopes of hydrogen and oxygen and water chemistry characteristics of water bodies can reveal the current status of water environment and water cycle in the river basin,which is of great significance for the reasonable protection and adoption of water resources.This paper mainly analyzes the composition of constant ions by two main rivers in the west of Tianshan(Ili River and Bortala River).The mathematical statistic method,water chemistry diagram and other methods were used to discuss the characteristics of water chemistry,hydrogen and oxygen isotopes and their influencing factors,and to study the variation law along the way.On this basis,the irrigation suitability of the two rivers provides a scientific basis for the assessment of the water environment in the western section of the Tianshan Mountains.The results of this study show that:(1)The pH value of Ili River water in the study area is 7.85⁸.14,with an average value of 8.01.The pH value of the Bortala River water ranges from 8.21 to9.46,with an average value of 8.55.The water bodies of Ili River and Bortala River are weakly alkaline,and the main anions and cations are HCO₃^-and Ca²⁺.The cation content of the two rivers in the study area was Ca²⁺>Na⁺>Mg²⁺>K⁺,and the anion content was HCO₃^->SO₄^2->Cl^-.Piper chart classification shows that the chemical types of the two rivers are HCO₃^-—Ca²⁺—Mg²⁺.(2)The size of TDS in the water samples of Ili River and Bortala River is mainly determined by the concentration of HCO₃^-and Ca²⁺in the water.HCO₃^-and Ca²⁺are the main control ions of river water quality.River water chemistry is mainly controlled by rock weathering.Carbonate weathering obviously affects the water chemical composition and characteristics of the study area.(3)Make spatial distribution maps of the constant ions,pH,conductivity and TDS components in the waters of Ili River and Bortala River to analyze the changes along the way.The content of water chemical components in the water of the Ili River gradually increased with the elevation.The content of water chemical components in the water of Bortala River gradually increased from upstream to downstream.(4)According to the?D and?¹⁸O sample data collected in the river water of the Ili and Bortala rivers,the equation of the waterline(SWL)of the Ili river is obtained:?D=6.85?¹⁸O-17.49(R²=0.67).The distances are 6.85 and 17.49‰.Bortala River Waterline(SWL)equation:?D=3.29?¹⁸O-57.3(R²=0.48),its slope and intercept are 3.29 and 57.3‰,respectively.The correlation between the hydrogen and oxygen isotopes in the water of the Ili and Bortala rivers and the latitude and longitude reflects the continental effect of the distribution of hydrogen and oxygen isotopes in the waters of the Ili and Bortala rivers.(5)According to drawing USSL diagram and Wilcox diagram,it can be seen that the variation range of Ili River EC is 197.9⁵73.5?S·cm^-1,with an average value of 407.3?S·cm^-1.The EC of Bortala River varies from137.4¹232?S·cm^-1,with an average value of 374.9?S·cm^-1.The sample points are in the C1 and C2areas.93%of the water samples from the Ili River and Bortala River fell in the good area.The adaptability of water irrigation in Ili River and Bortala River is evaluated as suitable for irrigation.From the results of the study,it is concluded that the macro ions in the water bodies of the Ili River and Bortala River are mainly affected by the weathering of rocks.The adaptability of water irrigation in Ili River and Bortala River is evaluated as suitable for irrigation.The research results are of great significance to the assessment of the water environment in the western section of the Tianshan Mountains and the sustainable use of water resources.