Reducing the ambiguity of karst aquifer models by pattern matching of flow and transport on catchment scale

Abstract. Assessing the hydraulic parameters of karst aquifers is a challenge due to their high degree of heterogeneity. The unknown parameter field generally leads to a high ambiguity for flow and transport calibration in numerical models of karst aquifers. In this study, a distributive numerical model was built for the simulation of groundwater flow and solute transport in a highly heterogeneous karst aquifer in south western Germany. Therefore, an interface for the simulation of solute transport in one-dimensional pipes was implemented into the software Comsol Multiphysics® and coupled to the three-dimensional solute transport interface for continuum domains. For reducing model ambiguity, the simulation was matched for steady-state conditions to the hydraulic head distribution in the model area, the spring discharge of several springs and the transport velocities of two tracer tests. Furthermore, other measured parameters such as the hydraulic conductivity of the fissured matrix and the maximal karst conduit volume were available for model calibration. Parameter studies were performed for several karst conduit geometries to analyse the influence of the respective geometric and hydraulic parameters and develop a calibration approach in a large-scale heterogeneous karst system. Results show that it is not only possible to derive a consistent flow and transport model for a 150 km2 karst area, but that the combined use of groundwater flow and transport parameters greatly reduces model ambiguity. The approach provides basic information about the conduit network not accessible for direct geometric measurements. The conduit network volume for the main karst spring in the study area could be narrowed down to approximately 100 000 m3.

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Reducing the ambiguity of karst aquifer models by pattern matching of flow and transport on catchment scale

Hydrology and Earth System Sciences ◽

10.5194/hess-19-893-2015 ◽

2015 ◽

Vol 19 (2) ◽

pp. 893-912 ◽

Cited By ~ 12

Author(s):

S. Oehlmann ◽

T. Geyer ◽

T. Licha ◽

M. Sauter

Keyword(s):

Groundwater Flow ◽

Solute Transport ◽

Karst Aquifer ◽

Karst Area ◽

Hydraulic Parameters ◽

Karst Aquifers ◽

Flow And Transport ◽

Model Ambiguity ◽

Karst Conduit ◽

Conduit Network

Abstract. Assessing the hydraulic parameters of karst aquifers is a challenge due to their high degree of heterogeneity. The unknown parameter field generally leads to a high ambiguity for flow and transport calibration in numerical models of karst aquifers. In this study, a distributed numerical model was built for the simulation of groundwater flow and solute transport in a highly heterogeneous karst aquifer in south-western Germany. Therefore, an interface for the simulation of solute transport in one-dimensional pipes was implemented into the software COMSOL Multiphysics® and coupled to the three-dimensional solute transport interface for continuum domains. For reducing model ambiguity, the simulation was matched for steady-state conditions to the hydraulic head distribution in the model area, the spring discharge of several springs and the transport velocities of two tracer tests. Furthermore, other measured parameters such as the hydraulic conductivity of the fissured matrix and the maximal karst conduit volume were available for model calibration. Parameter studies were performed for several karst conduit geometries to analyse the influence of the respective geometric and hydraulic parameters and develop a calibration approach in a large-scale heterogeneous karst system. Results show that it is possible not only to derive a consistent flow and transport model for a 150 km2 karst area but also to combine the use of groundwater flow and transport parameters thereby greatly reducing model ambiguity. The approach provides basic information about the conduit network not accessible for direct geometric measurements. The conduit network volume for the main karst spring in the study area could be narrowed down to approximately 100 000 m3.

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Numerical Simulation of Groundwater Flow and Solute Transport in a Karst Aquifer with Conduits

Groundwater - Contaminant and Resource Management ◽

10.5772/63766 ◽

2016 ◽

Cited By ~ 2

Author(s):

Bill X. Hu ◽

Zexuan Xu

Keyword(s):

Numerical Simulation ◽

Groundwater Flow ◽

Solute Transport ◽

Karst Aquifer

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Editorial of Special Issue “Advances in Groundwater Flow and Solute Transport: Pushing the Hidden Boundary”

Water ◽

10.3390/w11030457 ◽

2019 ◽

Vol 11 (3) ◽

pp. 457

Author(s):

Hongbin Zhan ◽

Quanrong Wang ◽

Zhang Wen

Keyword(s):

Numerical Methods ◽

Groundwater Flow ◽

Solute Transport ◽

Vadose Zone ◽

Regional Scale ◽

Chemical Transport ◽

Low Permeability ◽

Special Issue ◽

Flow And Transport ◽

Wide Range

The theme of this special issue is to explore the new territories beyond conventional subsurface flow and transport theories. We have selected 12 articles in this special issue and these articles cover a wide range of problems including (1) Non-Fickian chemical transport in various environments; (2) Non-Darcian flow; (3) Flow and transport in low-permeability media; (4) Vadose zone process; (5) Regional scale groundwater flow and groundwater-surface interaction; (6) Innovative numerical methods. The major contributions of these papers are summarized in this editorial.

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Laboratory analog and numerical study of groundwater flow and solute transport in a karst aquifer with conduit and matrix domains

Journal of Contaminant Hydrology ◽

10.1016/j.jconhyd.2009.08.004 ◽

2009 ◽

Vol 110 (1-2) ◽

pp. 34-44 ◽

Cited By ~ 38

Author(s):

Jonathan Faulkner ◽

Bill X. Hu ◽

Stephen Kish ◽

Fei Hua

Keyword(s):

Groundwater Flow ◽

Solute Transport ◽

Numerical Study ◽

Karst Aquifer ◽

Matrix Domains ◽

Laboratory Analog

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Assessing lateral flows and solute transport during floods in a conduit-flow-dominated karst system using the inverse problem for the advection–diffusion equation

Hydrology and Earth System Sciences ◽

10.5194/hess-21-3635-2017 ◽

2017 ◽

Vol 21 (7) ◽

pp. 3635-3653 ◽

Cited By ~ 15

Author(s):

Cybèle Cholet ◽

Jean-Baptiste Charlier ◽

Roger Moussa ◽

Marc Steinmann ◽

Sophie Denimal

Keyword(s):

Inverse Problem ◽

Solute Transport ◽

Unsaturated Zone ◽

Flood Routing ◽

Saturated Zone ◽

Karst System ◽

Advection Diffusion Equation ◽

Advection Diffusion ◽

Karst Conduit ◽

Conduit Network

Abstract. The aim of this study is to present a framework that provides new ways to characterize the spatio-temporal variability of lateral exchanges for water flow and solute transport in a karst conduit network during flood events, treating both the diffusive wave equation and the advection–diffusion equation with the same mathematical approach, assuming uniform lateral flow and solute transport. A solution to the inverse problem for the advection–diffusion equations is then applied to data from two successive gauging stations to simulate flows and solute exchange dynamics after recharge. The study site is the karst conduit network of the Fourbanne aquifer in the French Jura Mountains, which includes two reaches characterizing the network from sinkhole to cave stream to the spring. The model is applied, after separation of the base from the flood components, on discharge and total dissolved solids (TDSs) in order to assess lateral flows and solute concentrations and compare them to help identify water origin. The results showed various lateral contributions in space – between the two reaches located in the unsaturated zone (R1), and in the zone that is both unsaturated and saturated (R2) – as well as in time, according to hydrological conditions. Globally, the two reaches show a distinct response to flood routing, with important lateral inflows on R1 and large outflows on R2. By combining these results with solute exchanges and the analysis of flood routing parameters distribution, we showed that lateral inflows on R1 are the addition of diffuse infiltration (observed whatever the hydrological conditions) and localized infiltration in the secondary conduit network (tributaries) in the unsaturated zone, except in extreme dry periods. On R2, despite inflows on the base component, lateral outflows are observed during floods. This pattern was attributed to the concept of reversal flows of conduit–matrix exchanges, inducing a complex water mixing effect in the saturated zone. From our results we build the functional scheme of the karst system. It demonstrates the impact of the saturated zone on matrix–conduit exchanges in this shallow phreatic aquifer and highlights the important role of the unsaturated zone on storage and transfer functions of the system.

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