Study On Tempal And Spatial Characteristics And Evolutio Mechanism Of Hydrochemistry In Tarim River Basin

Tarim River is the longest continental river in China which was known as “The Riverof Life”. It played an important role in to contain region social development andecological stability. The hydrochemical characteristic of water body of basin is the criticalfactor of water source utilizability. This paper aimed to research basin hydrochemicalcharacteristic, controlling factors and evolution mechanism by collecting and analyzingsurface water and groundwater samples within Tarim River basin. We got followingconclusion through reserch job:1) Four water types were finded by hierarchical cluster analyzing based onhydrochemical data. Ca-Mg-SO4-HCO3water type was located in Aksu River and upperreach of Tarim River; Na-Mg-SO4-HCO3was located in Hotan River; Mg-Ca-HCO3watertype was located in Kaidu River; Na-Mg-Cl-SO4water type was located in lower reach ofTarim River.2) Major rock weathering process of basin surface water contained dissolution ofsilicate, calcite, dolomite, gypsum, halite and epsomite.3) Seasonal fluctuations were shown on hydrochemistry of study area that highestTDS value in every March to June and lowest TDS value in every June to August. Majorions shown same trend with TDS that Na+and Cl-had best consistency.4) Nine kinds of groundwater types were appeared in study areas which wereexpressed as Na-Mg-Cl-SO4, Na-Cl-SO4, Na-Mg-Cl-HCO3, Na-Ca-Cl-SO4,Na-Mg-HCO3-Cl, Na-Cl, Na-Mg-Cl, Na-Cl-HCO3and Na-Mg-HCO3-SO4. Most watertypes were Na-Mg-Cl-SO4. Hydrochemical compositions of groundwater were differerntbetween sections’ different well.5) According to the Groundwater and river water mixing proportion of modelingresult we concluded that: samples of groundwater from MA, ME and G monitoringsections were got little recharging from river water and samples of groundwater from Cmonitoring section were got ample recharging from river water from November,2010toMarch,2011; samples of groundwater from MA, ME and G monitoring sections weregot clearly increased amount of recharging from river water from March to June,2011;samples from MA monitoring section were got a certain amount of recharging from riverwater from August to November,2011. 6) As a result of mineral migration simulation, halite dissolution was the majorprocess of hydrochemical evolution which was especially shown on high salinitygroundwater far from river of ME and C monitoring sections. Cation exchanges werewidespread about hydrochemical evolution process in study area groundwater whichmostly exchanged between Na+and Ca2+.