根据乌鲁木齐河源区2003—2004年度的大气降水样品、1号冰川一个完整年周期的连续雪坑样品及哈密庙儿沟平顶冰川和奎屯51号冰川雪坑样品的pH和电导率资料,系统探讨大气降水、表层雪、雪坑样品中pH和电导率的季节变化特征和沉积过程中pH和电导率的变化特点,以及不同冰川区雪坑中pH值和电导率的空间差异。结果表明:大气降水及表层雪中pH和电导率有着相似的季节变化趋势,主要受冰川所在区域大气中可溶性离子浓度和沉积后过程的影响;对1号冰川大气降水、表层雪和雪坑样品中pH和电导率的对比分析发现,从降水到表层雪,最后到雪坑样品的演化过程中,pH和电导率均呈减小趋势,而且pH和电导率的最高值均出现在春季;自西向东随着地理环境的变化,雪坑中样品的pH值呈升高趋势,哈密庙尔沟平顶冰川最大,乌鲁木齐河源1号冰川次之,奎屯哈希勒根51号冰川最小,但电导率却呈现出了不同的变化规律。
Analysis of pH and electrical conductivity in precipitation samples collected from April 2003 to April, 2004, surface snow and snowpits samples collected successively in a weekly basis from April 2003 to April, 2004 on the east branch of Glacier No. 1 at the headwaters of Urumqi River and three snowpits samples which collected at the Miaoergou Glacier in Hami, Glacier No. 1 at the headwaters of Urumuqi River and Haxilegen Glacier No. 51 in Kuitun. The pH and electrical conductivity in precipitation samples and surface snow show obvious seasonal variation, pH and electrical conductivity reach maximum in spring and summer, reach minimum in fall and winter, the value of pH and electrical conductivity in surface snow samples is less than that of the precipitation samples which are associated with the concentration of soluble ions in atmosphere of the study area. The study of precipitation/surface snow/snowpits elution process indicated that the pH and electrical conductivity displayed decreasing trend in general, but the values of pH and electrical conductivity in spring were higher than that in other seasons. However, a significant positive relationship preserves between the pH and conductivity values of the precipitation,surface snow and snowpits. This fact implies that the post-depositional processes do not shift the relationship between the pH and conductivity. The analysis of the three snowpits of the No. 1, No. 51 and Miaoergou reflects the spatial difference of pH and electrical conductivity that is influenced by regional Asian dust and anthropogenic. The average pH value in Miaoergou is greater than that in other two sites, just as the case of high dust concentration at this site.