加速器质谱中心知识库

Conventional hydrochemical techniques and statistical analyses were applied to better understand the solute geochemistry and the hydrochemical process of shallow groundwater in the Qinghai Lake catchment. Shallow groundwater in the Qinghai Lake catchment is slightly alkaline, and is characterized by a high ion concentrations and low water temperature. The total dissolved solids (TDS) in most of the samples are < 1,000 mg/L, i.e. fresh water and depend mainly on the concentration of SO4 (2-), Cl- and Na+. Groundwater table is influenced directly by the residents' groundwater consumption. Most of the groundwaters in the Qinghai Lake catchment belong to the Ca2+(Na+) -HCO3 (-) type, while the Qinghai Lake, part of the Buha (BHR) and the Lake Side (LS) samples belong to the Na+-Cl- type. The groundwater is oversaturated with respect to aragonite, calcite and dolomite, but not to magnesite and gypsum. Solutes are mainly derived from strong evaporite dissolution in Daotang, BHR and LS samples and from strong carbonate weathering in Hargai and Shaliu samples. Carbonate weathering is stronger than evaporite dissolution with weak silicate weathering in the Qinghai Lake catchment. Carbonate weathering, ion exchange reaction and precipitation are the major hydrogeochemical processes responsible for the solutes in the groundwater in the Qinghai Lake catchment. Most of the shallow groundwaters are suitable for drinking. More attention should be paid to the potential pollution of nitrate, chloride and sulfide in shallow groundwater in the future.