唐古拉冬克玛底冰川流域pH值和电导率分析

Variations of pH Value and Electrical Conductivity in the Dongkemadi Basin,Tanggula Range

2005-05-11～2005-09-27,在青藏高原唐古拉段冬克玛底冰川流域对融水径流和草地径流分别进行采样.对样品的pH值和电导率进行了分析.结果表明,研究区环境受人类活动影响很小.借助电导率水量来源模型对冬克玛底河流量进行划分,暖季径流主要以冰川冰融水补给为主,占总流量的62%以上,其次是积雪融水和降雨补给,其中,第1、3阶段的积雪融水补给分别占31%和37%,第2阶段的降雨补给占17%左右;土壤冻结水消融对径流贡献很小,占2%以下.

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 orecioitation moralities variation trends of oH value and EC are following an orderd snow 〉 rainwater 〉 hailstone.