摘要
利用多参数自动记录仪CTDP300对具有不同土地利用分布格局的贵州普定陈旗和灯盏河两个岩溶泉域的降雨量、泉水位、水温、pH值和电导率进行了一个完整水文年的连续监测,并依据化学平衡热力学原理进行计算,得到连续的水的CO2分压(PCO2)和方解石饱和指数(SIc)。结果表明这两个泉的这些水化学指标均呈现出明显的季节变化和暴雨动态变化。然而,两泉水的这些变化具有明显的差异:对于土壤分布较多和水田分布在排泄区的陈旗泉而言,HCO3-和PCO2较高,而pH和SIc值明显低于土壤分布较少且水田分布于补给区的灯盏河泉,且变幅较小。此外在暴雨后,陈旗泉pH升高、PCO2降低,而灯盏河泉pH降低、PCO2升高。这些反映了不同土地利用分布格局对岩溶水化学调节作用的差异。灯盏河泉Ca2+、SO2-4、Mg2+和EC较高主要是其流域中石膏和白云岩含量较多的缘故。这些发现说明,pH、电导率、HCO3-、Ca2+、SO42-、Mg2+、PCO2和SIc等岩溶水化学参数可以作为不同土地利用分布格局和环境变化的重要指标。
With the multi-parameter auto-recordable instrument CTDP300, high resolution rainfall, stage, temperature, pH and conductivity of Chenqi and Denzhanhe karst springs, which formed under different land use patterns at Puding, Guizhou province, China were monitored. A thermodynamic model was used to link the continuous data to monthly water quality data allo-wing the calculation of CO2 partial pressure （PCO2 ） and calcite saturation index （SIc） on a continuous basis. Marked seasonal and storm-scale variations were observed for pH, conductivity, PCO2 and Sic of the springs, indicating that both springs are dynamic and variable systems. However, there are differences in magnitudes and direction of the variations of these features between these two springs. The higher PCO2 and HCO3^- concentration and lower pH and SIC in Chenqi karst spring than those in r Denzhanhe spring tend to be related to the difference in land use patterns between Chenqi spring and Dengzhanhe spring catchment areas. In the Chenqi catchment area, there is larger soil cover and the paddy land locates in the discharge area, both of which produce and keep more CO2 in the soil-aquifer system, while in the Dengzhanhe catchment area, there is less soil cover, and the paddy land is mainly in the recharge area. Moreover, the pH increased and PCO2 decreased in Chenqi spring due to more carbonate rock breccias dissolution in soil, while the pH decreased and PCO2 increasea in Dengzhanhe spring. These findings show the differences in karst spring hydrochemical modulation by different land use patterns. In addition, the higher concentrations of Ca^2＋ , SO4^2- , Mg^2＋ and the eleetronic conductivity of Dengzhanhe spring are due to more gypsum and dolomite minerals in strata of Dengzhanhe karst spring catchment. All these indicate that the karst hydrochemical parameters, e. g. , pH, elec-tronic conductivity, HCO3^- , Ca^2＋ , SO4^2- , Mg^2＋ , PCO2 and SIc, can serve as indicators of different land use patterns and environmental changes.
出处
《地球与环境》
CAS
CSCD
北大核心
2009年第3期214-220,共7页
Earth and Environment
基金
中科院“百人计划”项目
中国科学院知识创新工程重要方向项目(kzcx2-yw-306)
国家自然科学基金项目(40872168)
国家社会公益项目(2005DIB3J067)资助
