The Groundwater Source Discussion Of Gurinai Lake Area Of Alxa In Inner Mongolia

Gurinai Lake area is located in the Alxa of Inner Mongolia Autonomous Region of China,the west of which is Heihe River,the second largest inland river in China,and the east of which is Badain Jaran Desert,one of the four largest desert of china;belongs to the most dry area of Northwest China.It's climate is dry,the annual precipitation is less than 50 mm,the evaporation is as high as 2000 mm.There are lake ripples,dense springs,flourishing reeds in Gurinai Lake area.The groundwater,buried very shallow,is very moor.A lot of Chinese and foreign scientists are attracted by Its abundant source.On the basis of field section,outcrop observation,water sampling,and relevant software for hydrochemical data processing,the paper is contrast with the water chemistry and isotopes characteristics of the Heihe River and the Badain Jaran Desert,discusses the source of groundwater in the study area.Hydrochemical and isotopic data analyses indicate that:The TDS of Gurinai Lake area is 1143⁵2619mg/L.Along the Gurinai lake area from east to west,the TDS degree becomes smaller,from salt water to brackish water.The anions in water samples are mainly chloride and sulfate ions in the lake region,change into bicarbonate ions from West Lake.Cations have been dominated by sodium ions.The water chemistry type changed from Cl·SO₄-Na to HCO₃·CO₃-Na,and finally turned into HCO₃·SO₄·Cl-Na.Gurinai Lake area isotope D values ranged from-54‰ to-20.4‰,and 18 O values ranged from-2.7‰ to 2‰.The TDS of the Heihe River is 524⁹827mg/L.In the upper reaches of Gobi area,the cations in groundwater are dominated by calcium ions.The dominant anion is bicarbonate ions.The hydrochemical type is HCO₃·SO₄-Ca·Mg.Ejina is the evaporation severe region,the lower reaches of the high water table.Cations are dominated by sodium ions and anions are dominated by chlorine ions.The isotope D values ranged from-46‰ to-11.8‰,and 18 O values ranged from-2 ‰ to 1.3‰.Comparison of the chemical and isotopic characteristics of Gurinai lake,Heihe River and The Badain Jaran Desert water indicate: There is relation between The Gurinai Lake area groundwater and The Heihe River.There is a graben fault zone between the Heihe River and the Gurinai Lake area.The fault zone is the ancient river channel of the Heihe River.Gurinai Lake area groundwater mainly originates from the Heihe River by lateral recharge graben fault of Shao Ma camp in Dingxin,middle reaches of the Heihe River.The regional aquifer is controlled by the water conductive fault.