Role of epikarst in near-surface hydrological processes in a soil mantled subtropical dolomite karst slope: implications of field rainfall simulation experiments
Role of epikarst in near-surface hydrological processes in a soil mantled subtropical dolomite karst slope: implications of field rainfall simulation experiments
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表层岩溶在土幔亚热带白云岩岩溶斜坡近地表水文过程中的作用：野外降雨模拟实验的意义
DOI：
10.1002/hyp.10650
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发表时间：
2016-02-28
影响因子：
3.2
通讯作者：
Wang, Kelin
中科院分区：
文献类型：
--
作者：
Fu, Zhiyong;Chen, Hongsong;Wang, Kelin
表层岩溶对岩溶区产流有很强的控制作用，但在岩溶区表层岩溶对产流的控制作用尚不清楚。采用小区尺度降雨模拟试验，研究了不同降雨强度（低、高）和前期水分条件（干、湿）下表层岩溶对西南亚热带座舱岩溶区近地表水文过程的影响。开挖到表层岩溶下边界的沟槽允许识别整个土壤-表层岩溶体系结构系统中的流动路径，从而便于使用两阶段水文演变假设的概念模型进行水平衡计算。降雨量的70%以上通过浅层土壤垂直运移，并通过表层岩溶作用进行再分配，表现为土壤-表层岩溶界面的地下水流、表层岩溶表面的凹陷充填、表层岩溶的蓄水和深层渗流。表层岩溶水调蓄能力为表层岩溶面凹陷充填、表层岩溶持水、表层岩溶渗流和深层渗流之和，湿前期为58 mm，干前期为223 mm。土壤-表层岩溶系统的总径流量以饱和地下径流为主，表现出一个受表层岩溶储水量控制的阈值过程（在干旱前期条件下可储存多达181 mm的降雨水）。我们的研究证明，尽管表层岩溶相对不发达，覆盖的土壤地幔，它仍然产生了强烈的影响，近地表水文过程，因此应充分考虑在未来的模拟水补给和消耗动态在这个综合的土壤表层岩溶系统。版权所有（c）2015约翰威利父子有限公司
Epikarst exerts a strong control on run-off generation in karst regions, but it is still unclear in karst regions. Our study aimed to demonstrate the effect of epikarst on near-surface hydrological processes in a subtropical cockpit karst region of southwest China, using plot-scale rainfall simulation experiments with different rainfall intensities (low and high) and antecedent moisture conditions (dry and wet). A trench excavated to the epikarst lower boundary allowed identification of flow pathways in the entire soil-epikarst architecture system, thus facilitating the water balance calculations using a conceptual model with the assumption of a two-stage hydrological evolution. More than 70% of the total rainfall water moved vertically through the shallow soil layer and then was redistributed by the epikarst as subsurface flow occurring on the soil-epikarst interface, depression filling on epikarst surface, water held by epikarst and deep percolation. Epikarst water regulation capacity, defined as the sum of depression filling on epikarst surface, water held by epikarst, epikarst seepage flow and deep percolation, was 58mm (wet antecedent condition) and 223mm (dry antecedent condition). Total run-off from the soil-epikarst system was dominated by saturated subsurface flow showing a threshold process controlled by epikarst storage capacity (storing as much as 181mm of rainfall water under dry antecedent condition). Our study proved that despite the epikarst being relatively poorly developed and covered by a soil mantle, it still exerted a strong influence on near-surface hydrological processes and thus should be adequately considered in future modelling of water recharge and depletion dynamics in this integrated soil-epikarst system. Copyright (c) 2015 John Wiley & Sons, Ltd.