瓦里关地区大气降水化学特征及离子来源
Chemical Characteristics and Potential Sources of Precipitation in Waliguan Area
中文摘要：
基于瓦里关地区2011—2019年采集的604个降水样品，分析了降水的pH值、电导率及离子浓度特征，并应用因子分析、富集因子、相关分析及后向轨迹法，讨论了降水化学特征和离子来源。结果表明：1）瓦里关地区降水pH值变化范围为4.37～8.13，加权平均值为6.13；2）电导率变化范围为 2.47～153.2 μs/cm，加权平均值为14.87 μs/cm；3）离子总浓度变化范围为21.46～2027.55 μeq/L，加权平均总浓度为232.05 μeq/L，各离子加权平均浓度大小顺序为Ca2＋＞NH4＋＞SO42－＞NO3－＞Cl－＞Na＋＞Mg2＋＞F－＞K＋；Ca2＋是降水中主要的阳离子，其浓度为89.73 μeq/L，对离子总浓度的贡献率为39%，SO42－为降水中主要的阴离子，其浓度为38.34 μeq/L，对离子总浓度的贡献率为17%；瓦里关地区降水中各离子浓度除NH4＋外，均表现出冬春季偏高，夏春季较低的趋势；4）中和因子分析表明，Ca2＋、NH4＋对降水酸性的中和起主导作用；5）海盐示踪法和相关性分析显示，研究区降水离子主要来自陆源贡献，Na＋与Cl－基本来源于海源，a2＋、NO3－和SO42－基本由陆源贡献，海源和陆源对K＋、Mg2＋都有一定的贡献；6）后向轨迹分析显示，瓦里关地区降水离子浓度主要受西风源和局地源影响。
中文关键词：
瓦里关，降水化学，相关性分析，富集因子，后向轨迹
KeyWords：
Waliguan, precipitation chemistry, correlation analysis, enrichment factor, backward trajectory
Abstract：
Based on 604 precipitation samples collected from 2011 to 2019 in Waliguan Area, the pH, conductivity and ion concentration of precipitation were analyzed, and the chemical characteristics and ion sources were discussed by factor analysis, enrichment factor analysis, correlation analysis and backward trajectory method. The results show that: 1) The pH value of precipitation in Waliguan Area ranges from 4.37 to 8.13, with a weighted average of 6.13. 2) The conductivity varies from 2.47 to 153.2 μs/cm, with a weighted average of 14.87 μs/cm. 3) The total ion concentration varies from 21.46 to 2027.55 μeq/L, with a weighted average of 232.05 μeq/L; The weighted average concentration ion size order is Ca2＋＞NH4＋＞SO42－＞NO3－＞Cl－＞Na＋＞Mg2＋＞F－＞K＋. Ca2＋ is the main cation in precipitation, and its concentration of 89.73 μeq/L contributes 39% to the total ion concentration, while SO42－ is the main anion in precipitation, and its concentration of 38.34 μeq/L contributes 17% to the total ion concentration. Except NH4＋, the concentration of each ion in precipitation in Waliguan Area shows a trend of higher in winter and spring, and lower in summer and spring. 4) Neutralization factor analysis shows that Ca2＋ and NH4＋ play a leading role in the neutralization of precipitation acidity. 5) The sea salt tracer method and correlation analysis indicate that precipitation ions in the study area are mainly from terrestrial sources, Na＋ and Cl－ are mainly from marine sources, Ca2＋, NO3－ and SO42－ are mainly from terrestrial sources, and both marine and terrestrial sources contribute to K＋ and Mg2＋ to a certain extent. 6) Backward trajectory analysis shows that the precipitation ion concentration in Waliguan Area is mainly affected by the west wind source and local sources.