Analysis Of Temporal And Spatial Variation Characteristics Of The Typical Inland River On The Hydrochemical Characteristics In The Middle Of Tianshan Mountains

Water is a very important source of human life.Human survival and development cannot be separated from water resources.The focus of human attention is on the security of water resources.River water is the most widely used and freshwater resource for human beings.The study of river water chemistry has important guiding significance for clarifying the quality of water resources and rationally exploiting water resources.In recent years,the global climate has become warmer,and annual snow cover and glacial meltwater have increased in alpine and high-cold areas.The water chemistry of rivers that supply glacial meltwater will change.Under the background of global warming,it is of great practical significance to study the hydrochemical characteristics of the inland river basin in arid regions.In this study,a typical inland river,the Urumuqi River Basin,was selected as the research object in the middle Tianshan Mountain area.Six stations were established at different altitudes along the Urumqi River Basin,and water samples were collected continuously from 2011 to 2013.A total of 52 sets of data were obtained.The content of water chemical ion concentration was tested on the data,mainly four main cations in water:Ca²⁺,Na⁺,Mg²⁺,K⁺;four main anions:HCO₃^-,SO₄^2-,Cl^-,CO₃^2-.Combined with the meteorological and hydrological data of the basin in the same period,the author analyzed the chemical characteristics of surface water in the Urumqi River Basin using water chemistry analysis method and SPSS statistical software.According to the characteristics of time and space changes,the article conducts in-depth analysis.In this paper,the inter-ion correlations of surface waters are studied.The article studied the controlling factors of the water chemistry characteristics of the basin.In order to further determine the factors controlling the chemical characteristics of water,the paper combines the water chemistry features of groundwater,precipitation,and glacier melt water sourced in the same period to compare the content and concentration of various ions.The results show:?1?The surface water in the Urumqi River Basin has low TDS and good water quality.The average TDS is lower than the TDS mean value of surface water in the arid region of the world,and is lower than the TDS mean value of surface water in the semi-arid region,but it is higher than the average TDS value of the total river water in the world.?2?The pH of the water is slightly alkaline.The change in pH shows a significant seasonality.During the dry period,the pH is high and the pH during the wet period is low.?3?The main ions controlling the surface water are HCO₃^-,Ca²⁺,and SO₄^2-.In cations,Ca²⁺is dominates,accounting for 75%of the total cation content.Among the anions,HCO₃^-and SO₄^2-are dominant,and their specific gravity is 61%and 29%of the total anion,which together accounts for 90%of the total anion.The order of ion concentration in the Urumqi River Basin is HCO₃^->Ca²⁺>SO₄^2->Cl^->Na⁺>Mg²⁺>K⁺>CO₃^2-.?4?The water chemistry of the Urumqi River has a clear seasonal trend.The TDS values are high in the early snow melting season,late spring and early summer season,and autumn snow melting season.The TDS value is low in summer.The water chemistry of the Urumqi River shows a significant interannual variation:the TDS value of surface water is lower in rainy years,and the TDS value of surface water is higher in drought years.Different seasons control the main ions of the water body differently.During the dry season,the river is Ca²⁺-HCO₃^-type.During the wet season,because of precipitation,glacially diluted rivers,the ion concentration is low,showing Ca²⁺-HCO₃^--SO₄^2-type.?5?As the altitude decreases,the ion concentration TDS values sequentially increase from site 1 to site 6 ions.The reason is that the source of the river has a lot of glacial melt water and atmospHeric precipitation supplies with very low TDS.Most of the area is covered with moraine.The soil in this area is young,so there is less soluble salt.As the alpine soil freezes,it is difficult to accumulate soluble salts on the surface.The sudden increase in SO₄^2-concentration in river water from station 1 to station 2 is mainly due to the presence of a gypsum interlayer in the aquifer of this section of river water,which releases a large amount of sulfuric acid and chloric acid.?6?The analysis of surface water chemistry shows that the main influencing factors controlling the chemical process of surface water in the basin are interactive water and rock movements.