Chemical Characteristics Of Yili River And Analysis Of Its Influencing Factors

As an important part of the hydrological cycle,rivers have hydrochemical characteristics that can indicate the quality of river water environment,regional environmental chemical characteristics,and the migration and transformation laws of different water bodies to a certain extent.The Yili River is located in the western part of Xinjiang.It is an extremely rare reentrant river flowing from low latitudes to high latitudes.Its unique geographical location makes it different from other rivers.Analyzing the hydrochemical characteristics of the Yili River can better evaluate the water resources and understand the regional hydrological cycle process.This paper takes the spring and summer water of the Yili River in Xinjiang as the research object.Based on the analysis of the meteorological,hydrological,and geological data of the river basin,the main stream of the Yili River and its tributaries are collected and analyzed and tested,focusing on the water and hydrochemical characteristics of the Yili River.The influencing factors are analyzed and discussed.Get the following conclusions and understandings:(1)The hydrogen and oxygen isotopes of Yili River water are more concentrated in summer than in spring,and the degree of evaporation and fractionation of river water is significant under the action of high temperature.Both hydrogen and oxygen isotopes show the characteristics of being gradually depleted from south to north,and gradually enriched from east to west.Both the Tekes River and the Yili River show an"anti-elevation effect"in summer and spring.The Tekes River may be affected by both the latitude effect and evaporation,and the Yili River may be affected by the latitude effect and tributary replenishment,along the direction of river runoff.Hydrogen and oxygen isotopes are gradually depleted.By analyzing the relationship between the?D and?¹⁸O of the Yili River and the characteristics of the deuterium surplus,it is found that the Yili River mainly receives the replenishment of atmospheric precipitation and glacial melt water in spring,and mainly receives the replenishment of atmospheric precipitation in summer.(2)The water quality of the Yili River is good,and the p H is generally weakly alkaline.The average concentration of main ions in spring is higher than that in summer.It may be due to the large precipitation in summer,which will dilute the main ions in the river water;in addition,the rainfall in spring is relatively high.Less,the contact time with the surrounding environment during the runoff process of the water body increases,and the dissolved ions are more.The average concentration of NO₃^-in the water of the Yili River in summer is greater than that in spring,which may be due to the increase in rainfall in summer and the increase in surface runoff,bringing in more nitrate-containing substances produced by human activities.(3)The analysis of Gibbs diagram and Piper diagram shows that the water chemical composition of the Yili River in summer and spring is mainly affected by carbonate weathering.Ca²⁺and Mg²⁺mainly come from carbonate rocks,followed by the dissolution of evaporite minerals,Na⁺and K⁺mainly come from evaporites,followed by the dissolution of carbonate and silicate minerals,and the main sources of Cl^-and SO₄^2-Weathering and dissolving of evaporite.(4)The chemical composition of the Yili River water is affected by the source of recharge and human activities.Through the TDS and main ion changes of the Tekes River water and groundwater,it is concluded that the Tekes River mainly replenishes the groundwater from the river water in summer,and the groundwater contributes to the river water.The influence of chemical composition is small.Through the changes in the molar ratio of SO₄^2-to Ca²⁺and the molar ratio of NO₃^-to Ca²⁺to analyze the impact of human activities on the chemical composition of river water,it is concluded that the Tekes River,the Kunes River and the Karsh River are mainly affected by agricultural activities and domestic sewage in summer;Yili River is mainly affected by industrial and mining activities;In spring,the Tekes River,Kunes River,Karsh River and Yili River are mainly affected by industrial and mining activities.(5)Using the correlation analysis method to analyze the correlation between land use types and the chemical composition of river water,it is found that in the land use types of Yili area,waters and unused land in Yili area have a positive effect on the river water environment in summer.Farmland and construction Land use has a negative effect on the river water environment;grassland has a positive effect on the river water environment in spring,and farmland and construction land have a negative effect on the river water environment in spring.