桂林硝盐洞滴水水文和水化学动态变化特征

Characteristics of hydrologic and hydrochemical regime of the dripping water in the Xiaoyan cave,Guilin

为认识裸露型岩溶包气带洞穴水文水化学动态变化特征,以桂林硝盐洞滴水为例,选取桂林硝盐洞3处滴水,对滴速、电导率、pH值、Ca2+、Mg2+、Sr2+进行监测,结果显示:(1)岩溶洞穴滴水的离子浓度与温度降水关系密切,高温多雨时节岩溶作用加快,洞穴滴水中Ca2+、Mg2+含量升高,同时强降雨会导致离子浓度产生很大波动;(2)滴水化学性质受到土壤、基岩顶板厚度、滴水量等的影响,土壤层越厚,滴水中Ca2+含量越高;(3)受"慢速补给"的滴水点,其滴水量与离子浓度呈正相关性,而受"快速补给"的滴水点,其滴水量与离子浓度呈负相关性;同时接受两种方式补给的滴水点,其滴水量和离子浓度变化剧烈,且呈良好的正相关性。

In order to know the dynamic characteristics of cavern hydrochemistry in bare karst aeration zone, three drip water points in the Xiaoyan cave are selected as the research site, and the dripping rate, conductiv- ity, pH, Ca2＋ , Mg2 , Sr＋ etc. are monitored. The results show that （1） ion concentration of the dripping water is of obvious relationship with temperature and precipitation, and high temperature and rainy weather will speed up karstification, make Ca2＋ , Mg2 content increase, heavy rain will bring about a great fluctua- tion in the concentration; （2） chemical properties are affected by soil and rock roof thickness as well as drip water yield, the thicker the soil layer, the higher the calcium ions content in the water＋ （3） the dripping wa- ter yield of the ＂slow recharge＂ dripping point shows a positive correlation with the ions content, but the dripping water yiel＇d of the ＂rapid recharge＂ dripping point shows a negative correlation with the ions con- tent, and when both ＂slow recharge＂ and ＂rapid recharge＂ dripping water exist at one point, the dripping water yield and ion content change violentlv,and the correlation is positive.