玉龙雪山地区不同海拔高度降水中常量无机离子特征分析

运用海盐示踪法计算了云南省丽江市玉龙雪山2005-07-26～2006-07-31不同海拔高度降水中常量无机离子非海洋来源的比例，计算结果显示Cl^-、Na⁺海洋源比重较高，平均海洋源比重分别为74.79％、73.53％. NO^-₃、SO^2-₄、K⁺ 、Mg²⁺ 、Ca²⁺主要是非海洋源，平均非海洋源所占的比重依次为100％、93.54％、97.29％、81.77％、99.66％. 统计图显示阳离子浓度的变化远远大于阴离子，阳离子浓度区间为0.51～5.26 mg/L，阴离子浓度区间为0.99～4.90 mg/L，由此推断阳离子来源构成比较复杂. 分析表明陆源离子，尤其是近源陆源离子对该地区降水的无机离子构成和离子浓度影响较大，2400～2950 m人类活动导致阴离子浓度较高，2950～4800 m降水的离子浓度受局地环流的影响较大，玉龙雪山地区基岩以石灰岩为主是造成降水中阳离子，尤其是Ca²⁺和Mg²⁺浓度较大的主要原因.

Characteristics of Constant Inorganic Ions in Precipitation at Different Altitudes Precipitation in Yulong Snow Mountain Area

According to the different altitudes precipitation samples in Yulong Snow Mountain area in Yunnan Province from July 26 2005 to July 31 2005, the precipitation chemical characteristics of different altitudes were analyzed with the sea salt iron tracer analysis method. Sea salt tracer analysis showed that Cl^-, Na⁺ had high proportion marine source, amounting 74.79% and 73.53% respectively while the other ions mainly were nonmarine sources. The average percentage of nonmarine sources of NO^-₃, SO^2-₄, K ⁺, Mg²⁺, Ca²⁺ were 100%, 93.54%, 97.29%, 81.77%, 99.66%. Statistics chart showed the changes of cation outweigh the anion greatly. The cation concentration ranged between 0.51-5.26 mg/L and anion concentration ranged between 0.99-4.90 mg/L, inferring the cation have more complicated sources. Further analysis showed terrestrial ions, especially near source terrestrial ion composition greatly impact the precipitation ion concentration. Human activities lead to higher anion concentration at alt. 2950-4800 m and precipitation ion concentration was correlated significantly with local atmospheric circulation. The most rock are limestone caused high precipitation cations in Yulong Snow Mountain, such as Ca²⁺ and Mg²⁺.