石羊河流域多水体酸根离子特征及影响因素

2014年7月~2015年6月在石羊河流域采集降水、地表水及地下水样品，使用离子色谱仪分析获取样品主要酸根离子含量，研究石羊河流域不同水体酸根离子特征、季节分异及其影响因素.结果显示：石羊河流域不同水体均呈弱碱性，酸根离子组成以SO₄^2-和HCO₃^-为优势离子，分别占酸根离子总量的38.68%和33.49%；不同季节水体酸根离子浓度差别较大，春季水体中酸根离子浓度最高，夏季最低，地下水季节变异小于地表水；地表水和地下水的酸根离子浓度都呈现出从上游到下游递增的规律，地表水酸根离子浓度大大低于地下水.碳酸盐的风化及蒸发岩溶解是酸根离子的主要来源，人类活动对石羊河流域水体已造成轻度污染.

Hydrochemical characteristics and control factors of acid anion in Shiyang River Basin

From July 2014 to June 2015, precipitation, surface water and groundwater samples were collected in Shiyang River Basin. The main acid ion contents in the samples were analyzed by ion chromatograph. The characteristics of acid ions in different water bodies of Shiyang River basin, seasonal differentiation and its influencing factors were studied. The results shown that all water samples were mildly alkaline and the acid radical ions consisted of SO₄^2- and HCO₃^- as dominant ions, which accounted for 38.68% and 33.49% of total anion, respectively. Obvious variations have been perceived during different seasons, which the highest anion content was in spring and the lowest value in summer. Seasonal variation of groundwater was smaller than that of surface water. The concentration of acid root ion in surface water is much lower than that of groundwater. The weathering of carbonate and the dissolution of evaporite were the main sources of acid ion. In addition, the human activities have caused mild pollution to the water body of the Shiyang River Basin.