Variations of pH Value and Electrical Conductivity in the Dongkemadi Basin,Tanggula Range
唐古拉冬克玛底冰川流域pH值和电导率分析

Investigation of meltwater chemistry may provide information to understand the significance of glacier in estimating of water provenance.Most notably,the role of electrical conductivity(EC) variation in meltwater during glacier melting season has attracted considerable attention,since this may reflect the water flux.Analyses for pH and EC in 229 bulk meltwater samples have provided information about water provenance at Dongkemadi Glacier basin,an outlet tongue from the Tanggula Pass,Tibetan Plateau.The samples were collected at 14:00 from 12~(th) May to 27~(th) September in 2005 at site of controlled meltwater flux.The results document the following findings.First phase of runoff was mainly supplied by snow and glacier ice meltwater,31% and 65%,respectively,and the snow including fresh snow and winter deposited snow.Secondary phase of flux primarily was supplied by glacier ice meltwater and precipitation,but meltwater of frozen water in soil also has some contribute to flux,but only 2%.Third phase,ice bulk meltwater decreased and fresh snow meltwater increased.In different precipitation modalities variation trends of pH value and EC are following an orderd snow>rainwater>hailstone.