Characterizing the heterogeneity of karst critical zone and its hydrological function: An integrated approach
Characterizing the heterogeneity of karst critical zone and its hydrological function: An integrated approach
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表征岩溶关键带的非均质性及其水文功能：一种综合方法
DOI：
10.1002/hyp.13232
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发表时间：
2018-09-15
影响因子：
3.2
通讯作者：
Tao, Min
中科院分区：
文献类型：
--
作者：
Chen, Xi;Zhang, Zhicai;Tao, Min
岩溶环境地下空间非均质性很强，碳酸盐岩的多相孔隙度和复杂的地貌特征导致水文过程在空间和时间上具有显著的变异性。这包括在不同位置进行各种流动(例如，快导管流动和慢压裂流动)的复杂交换。在这里，我们整合了各种最先进的方法，以了解这个受限程度较低的临界区环境的结构和功能。中国，利用地球物理、水文、示踪等手段，对贵州陈旗小流域驾驶舱岩溶临界区的水文功能进行了研究。利用电阻率层析成像(ERT)进行地球物理测量，推断了表层岩溶和下伏含水层渗透率的空间非均质性。谷底地区降水井的地下水位、坡度较大的泉水和集水口的流量对暴雨降雨补给和坡面水流表现出不同的水动力响应。利用水温和稳定水同位素(δD和δ18O)进行的示踪研究，可与对地下含水层渗透性的洞察结合起来使用，以解释地下水响应随地点和深度的变化，即来自暴雨的“新”水在多大程度上回灌并与岩溶含水层中“旧的”事件前的水混合。这种综合方法揭示了岩溶临界带的空间结构，并提供了跨空间和时间尺度的水文功能的概念性框架。
Spatial heterogeneity in the subsurface of karst environments is high, as evidenced by the multiphase porosity of carbonate rocks and complex landform features that result in marked variability of hydrological processes in space and time. This includes complex exchange of various flows (e.g., fast conduit flows and slow fracture flows) in different locations. Here, we integrate various “state‐of‐the‐art” methods to understand the structure and function of this poorly constrained critical zone environment. Geophysical, hydrometric, and tracer tools are used to characterize the hydrological functions of the cockpit karst critical zone in the small catchment of Chenqi, Guizhou Province, China. Geophysical surveys, using electrical resistivity tomography (ERT), inferred the spatial heterogeneity of permeability in the epikarst and underlying aquifer. Water tables in depression wells in valley bottom areas, as well as discharge from springs on steeper hillslopes and at the catchment outlet, showed different hydrodynamic responses to storm event rainwater recharge and hillslope flows. Tracer studies using water temperatures and stable water isotopes (δD and δ18O) could be used alongside insights into aquifer permeability from ERT surveys to explain site‐ and depth‐dependent variability in the groundwater response in terms of the degree to which “new” water from storm rainfall recharges and mixes with “old” pre‐event water in karst aquifers. This integrated approach reveals spatial structure in the karst critical zone and provides a conceptual framework of hydrological functions across spatial and temporal scales.