重庆芙蓉洞土壤渗透水-滴水的元素变化特征及其意义

Variation Characteristics of Elements in Soil Infiltrating Water-Drips around Furong Cave of Chongqing and Their Implications

通过对重庆芙蓉洞上覆表层岩溶泉水、土壤渗透水和洞穴滴水水化学特征的系统监测,发现3种水(泉水、土壤渗透水和滴水)元素的变化幅度在年内都有各自的变化范围,Ca2+、Mg2+、Sr2+和SO24-在土壤渗透水中年平均浓度分别为25.55,11.04,0.026,15.39mg/L,在表层岩溶泉水中分别为65.76,33.16,0.035,21.18mg/L,而在洞穴滴水中分别为64.37,37.87,0.044,11.38mg/L。3种水之间存在大致协调同步的季节变化规律:Ca2+、Mg2+、Sr2+浓度的变化呈枯水期变幅大、雨季变幅小的特征,SO24-浓度则因不同的点而存在一定差异。受土壤水热条件以及生物过程的季节性变化影响,土壤渗透水中各元素变化表现出一定的季节性。6个洞穴滴水中Ca2+、Mg2+和Sr2+浓度在冬季枯水期出现低值,MP2点的SO42-浓度随降雨的增加而逐渐增大。因此,不同滴水点运移的路径、时间和环境条件不同,导致对降水的季节响应也存在一定差异。

Through system monitoring to the hydrochemical characteristics about springs,infiltration waters and drips,it was found that there are different variation ranges among the three types of water in a year.The average concentration of Ca2＋,Mg2＋,Sr2＋ and SO2-4 were 25.55,11.04,0.026,15.39 mg/L in the soil infiltration of water;and 65.76,33.16,0.035,21.18 mg/L in spring water;while 64.37,37.87,0.044,11.38 mg/L in drips.The elements concentration of different kinds of water almost changed simultaneously and coordinately with the seasonal variation：The amplitude of concentration of Ca2＋,Mg2＋ and Sr2＋ would be larger in a dry season,while smaller in the rainy season.The amplitude of concentration of SO2-4 didn＇t have such characteristic.Affected by variations of the water and heat conditions about soil and also the variation of biological processes,the element content of soil waters showed some seasonal characteristic.The concentration of Ca2＋,Mg2＋ and Sr2＋ in drips were lower in the winter dry season,while the concentration of SO2-4 increased with the increases of rainfall.Thus different migration paths,time and environmental conditions of different drip points had lead to different response to precipitation.