Effects of passive-storage conceptualization on modeling hydrological function and isotope dynamics in the flow system of a cockpit karst landscape
Effects of passive-storage conceptualization on modeling hydrological function and isotope dynamics in the flow system of a cockpit karst landscape
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DOI：
10.5194/hess-26-5515-2022
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发表时间：
2022-11
影响因子：
6.3
通讯作者：
Guang-lu Li;Xi Chen;Zhicai Zhang;Lichun Wang;C. Soulsby
中科院分区：
文献类型：
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作者：
Guang-lu Li;Xi Chen;Zhicai Zhang;Lichun Wang;C. Soulsby
抽象的。在耦合流-同位素模型中概念化被动储存可以改善许多自然系统（如集水区或河流）中示踪剂输运的混合和衰减效应的模拟。然而，将不同的概念化的被动存储在复杂的岩溶流系统的模型的有效性仍然知之甚少。在这项研究中，我们开发了一个耦合的流量同位素模型，概念化的“快流”和“慢流”过程中的非均质含水层，以及在驾驶舱岩溶景观的陡坡和低洼的凹陷单元之间的水文连接。该模型测试对比配置的被动存储在快速和缓慢的流系统，并优化使用多目标优化算法的基础上详细的观测数据的流量和同位素动力学在中国西南部的陈旗流域。结果表明，一至三个被动存储区分布在山坡快/慢流水库和/或凹陷慢流水库提供了最佳的模型结构在研究流域。这种优化可以有效地提高出口流量和同位素特征的模拟精度。此外，最佳示踪剂辅助模型反映了山坡和洼地单元的主要水流路径和连接，为主要水文成分（例如，在岩溶流系统陡坡单元中，快速流占总流量的80%以上。我们的耦合流同位素模型岩溶系统提供了一种新颖的，灵活的工具，更现实的流域概念化，可以很容易地转移到其他驾驶舱岩溶流域。
Abstract. Conceptualizing passive storage in coupled flow–isotope models can improve the simulation of mixing and attenuation effects on tracer transport in many natural systems, such as catchments or rivers. However, the effectiveness of incorporating different conceptualizations of passive storage in models of complex karst flow systems remains poorly understood. In this study, we developed a coupled flow–isotope model that conceptualizes both “fast-flow” and “slow-flow” processes in heterogeneous aquifers as well as hydrological connections between steep hillslopes and low-lying depression units in cockpit karst landscapes. The model tested contrasting configurations of passive storage in the fast- and slow-flow systems and was optimized using a multi-objective optimization algorithm based on detailed observational data of discharge and isotope dynamics in the Chenqi Catchment in southwestern China. Results show that one to three passive-storage zones distributed in hillslope fast-/slow-flow reservoirs and/or depression slow-flow reservoirs provided optimal model structures in the study catchment. This optimization can effectively improve the simulation accuracy for outlet discharge and isotope signatures. Additionally, the optimal tracer-aided model reflects dominant flow paths and connections of the hillslope and depression units, yielding reasonable source area apportionment for dominant hydrological components (e.g., more than ∼ 80 % of fast flow in the total discharge) and solute transport in the steep hillslope unit of karst flow systems. Our coupled flow–isotope model for karst systems provides a novel, flexible tool for more realistic catchment conceptualizations that can easily be transferred to other cockpit karst catchments.