贵州普定陈旗岩溶泉水化学响应研究

Study on the Hydrochemical Response of Chenqi Karst Spring in Puding of Guizhou Province

[目的]了解岩溶泉的水化学动态变化,并探讨降雨过程中岩溶作用的机理。[方法]采用仪器自动记录、现场滴定和样品的室内测试相结合的方法研究了陈旗岩溶泉的水化学动态变化。[结果]HCO3-及Ca2+是陈旗岩溶泉水中的主要阴阳离子,分别占到80%以上。陈旗岩溶泉的水化学类型为HCO3--Ca型。Ca2+和HCO3-的浓度和泉水的电导率存在良好的线性关系([Ca2+]=0.225 8 Cond+0.8076,R2=0.983 8;[HCO3-]=0.469 7 Cond+8.698 6,R2=0.999 3)。泉水的季节性变化和昼夜动态变化趋向于与温度同变(夏季白天pH值低,冬季晚上pH值高)。暴雨期间,其水化学变化以稀释效应为主。[结论]陈旗岩溶泉的水化学动态变化反映了该区岩溶作用的强弱,该研究为探究大气中CO2的库源关系及全球环境变化提供了一种新的方法。

[Objective] The purpose was to know about the hydrochemical dynamic variations of karst spring and discuss the mechanism of karstification during raining. [Method] The hydroehemical dynamic variations of Chenqi karst spring were studied by the method of combining automatic recording by instrument and spot titration with lab testing of samples. [Result] The main anion and cation in the water of Chenqi karst spring were HCO3^- and Ca^2＋, accounting for over 80% resp. The hydrochemical type of Chenqi karst spring was HCO3^--Ca. The content, of Ca〉 and HCO3^- had good linear relationship with the conductivity of the spring water （[Ca^2＋]=0.225 8 Cond＋0.807 6, R^2=0.983 8; [HCO3^-]=0.469 7 Cond＋ 8.698 6, R^2=0.999 3）. The seasonal variations and diumal dynamic varitions of the spring water tended to accord with that of temperature （pH value was low in the daytime in summer and high in the night in winter.）. During rainfall period, the chemical variations of the spring water majored in dilution effect. [Conclusion] The hydrochemical dynamic variations of Chenqi karst spring reflected the karstification intensity of the area. The study provided a new method for researching the sink-source relationship of CO2 in air and the variations of global environment.