Numerical investigation of the combined effect of forced and free thermal convection in synthetic groundwater basins

Szijártó, Márk; Galsa, Attila; Tóth, Ádám; Mádl-Szőnyi, Judit

doi:10.1016/j.jhydrol.2019.03.003

Cited by 28 publications

(11 citation statements)

References 55 publications

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“…During the calculations, Darcy's equation and the Fourier-Kirchhoff equation were coupled and solved without source/sink, the fluid was incompressible and isothermic, and gravitational acceleration and dynamic viscosity were kept as constant. The study was stationary because of the relatively shallow (thickness: ~ 300 m, length: 17 km) model domain and thus the temperature difference between the boundaries, presumably the water table variation (large hydraulic head gradient) is the main driving force of fluid flow demonstrated by Szijártó et al (2019). Consequently, only conduction and advection (forced convection) were taken into account.…”

Section: Numerical Simulationmentioning

confidence: 99%

Groundwater flow system understanding of the lukewarm springs in Kistapolca (South Hungary) and its relevance to hypogene cave formation

et al. 2020

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Springs have an important role both in groundwater flow system understanding and in maintaining groundwater-related ecosystems. The aim of the research of the lukewarm karst springs in Kistapolca is to understand the origin of the elevated temperature (22-24 °C), i.e., whether it is the result of mixing of cold and thermal waters or it represents the terminal area of intermediate flow systems. This question has also an important relevance to the evaluation of recent cave formation in the area. In case of mixing of different waters dissolution by mixing corrosion could take place. This scenario was proposed for the formation of the Beremend Cave, which is situated in the close vicinity of the springs, and which is the only known cave of the area, where the passages are partly filled by water. Therefore, several methods, including geophysical, geochemical and stable isotope measurements, evaluation of continuous-time series of water level change, temperature, and electrical conductivity data and hydraulic evaluation of vertical flow conditions by pressure-elevation profiles were combined in order to acquire information about the hydrogeological environment and flow conditions in the area. The results show that a higher order flow system derived from the Villány Hills feeds the springs in Kistapolca without significant local influence. In addition, the results related to the Beremend Cave indicate that cave formation by mixing corrosion is not an active process today in the area, the cave is rather influenced by local processes.

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Section: Numerical Simulationmentioning

confidence: 99%

Groundwater flow system understanding of the lukewarm springs in Kistapolca (South Hungary) and its relevance to hypogene cave formation

et al. 2020

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“…The results of the coupled flux and heat modeling analyses are consistent with previous studies in other areas of the world. Groundwater flow on the basin scale is controlled by numerous factors: the configuration of the water table [35][36][37][40][41][42], the effects of temperature on fluid density and viscosity in heterogeneous anisotropic media [37,43], the effect of hydraulic conductivity contrasts and temperature boundaries [44], the three-dimensional flow field with the variations and areal distribution of heat affected by relief on the water table and permeability variations [37,45], advective heat transfer [29,30,42,45,46], temperature distributions for paleoflow systems [47,48], the modeling of heat as a groundwater tracer [49] and of large-scale flow [38], and the significance of basin asymmetry and geothermal assessments [36,37,50], among many others.…”

Section: Discussionmentioning

confidence: 99%

“…The conceptual model of flow is based on the groundwater conditions in the IB described in the previous section and the following considerations: (1) the flow system is gravity driven; (2) on the basin scale, there is a dynamic equilibrium between inputs and outputs, so the flow system can approximate a steady-state flow field; (3) K is homogeneous in each hydrogeological unit with main directions aligned with the coordinate axis, though anisotropic; (4) on a regional scale, fractured media can be estimated by equivalent porous media; (5) the water table in the mountains cannot be consistently higher than the topography; (6) its elevation cannot be too low either because this would be inconsistent with the existence of some springs or due to the position of the historical water table; (7) the flow at the boundary cannot be greater than the existing precipitation ranges [20][21][22][23][24][25][26][27][28][29][30][31][32][33]; and (8) in the scenarios in which the numerical analysis of coupled flow-heat transport processes is carried out, the role of topography in heat transport is considered in addition to the above assumptions [34][35][36][37].…”

Section: Conceptual Model Of Flowmentioning

confidence: 99%

Numerical Analysis of the Groundwater Flow System and Heat Transport for Sustainable Water Management in a Regional Semi-Arid Basin in Central Mexico

Ortega-Guerrero

2022

Water

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The Independence Basin is located in a semi-arid region of Mexico, delimited predominantly by volcanic mountains. Around 30 m3/s of water are extracted from regional aquifers mainly for agro-export activities, causing declines in the water table of up to 10 m/a, increased temperature and dissolved elements that are harmful to health and the environment. Regional groundwater coupled flow and heat transport under current conditions were studied on a basin-wide scale (7000 km2) using a three-dimensional finite-element model under steady-state conditions to provide support for water management decisions and transient modeling. Isothermal, forced and free thermal convection under existing hydrological conditions prior to pumping are analyzed. The results show that the interaction of topography-driven groundwater flow and buoyancy-driven free thermal convection are consistent with historical hydrological records, the characteristics of the water table, and thermal anomalies observed in the basin. The simulated groundwater recharge is near 7 ± 0.25 m3/s, a balance broken since the 1980s by extensive pumping. The results show the importance of considering the groundwater temperature, its transient response in the evolution of groundwater extraction, and the upward migration of a thermal front through the fractured aquifer that has increased risks for health and sustainability.

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“…These systems typically consisted of local, intermediate, and regional groundwater flow systems and are thought to exist in many hydrogeological environments, including endorheic basins (Figure 1a), coastal aquifers ( Figure 1b) (Wilson, 2005), hyporheic zones (Boano et al, 2014), and river basins (Zlotnik et al, 2011). Groundwater flow systems mediate a variety of geological, geophysical, and biogeochemical processes in both shallow and deep underground environments (Garven, 1995;Person et al, 1996;Schwartz & Domenico, 1973;Stuyfzand, 1999;Szijártó et al, 2019;Tóth, 1999). Understanding such groundwater flow systems is of great practical relevance to ore mineralization (Garven et al, 1993(Garven et al, , 1999Garven & Freeze, 1984;Raffensperger & Garven, 1995), petroleum migration (Garven, 1989), sediment diagenesis (Lee & Bethke, 1994), heat transfer (Szijártó et al, 2019), hydrochemical patterns (Gupta et al, 2015;Jiang et al, 2014;Stuyfzand, 1999;Wang et al, 2015), etc.…”

Section: Introductionmentioning

confidence: 99%

“…Groundwater flow systems mediate a variety of geological, geophysical, and biogeochemical processes in both shallow and deep underground environments (Garven, 1995; Person et al, 1996; Schwartz & Domenico, 1973; Stuyfzand, 1999; Szijártó et al, 2019; Tóth, 1999). Understanding such groundwater flow systems is of great practical relevance to ore mineralization (Garven et al, 1993, 1999; Garven & Freeze, 1984; Raffensperger & Garven, 1995), petroleum migration (Garven, 1989), sediment diagenesis (Lee & Bethke, 1994), heat transfer (Szijártó et al, 2019), hydrochemical patterns (Gupta et al, 2015; Jiang et al, 2014; Stuyfzand, 1999; Wang et al, 2015), etc.…”

Section: Introductionmentioning

confidence: 99%

Effects of Downward Intrusion of Saline Water on Nested Groundwater Flow Systems

Zhang

Jiao

et al. 2020

Water Resources Research

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Nested groundwater flow systems (NGFS) are commonplace in various hydrogeological environments, including endorheic basins and coastal aquifers. The subsystems of the NGFS can be spatially separated by streamlines around the internal stagnation points. At the discharge zones of the topographic depressions, saline water often emerges due to high evaporation in endorheic drainage basins or the combined effects of evaporation and intermittent seawater submersion in coastal areas. To date, there are limited studies that have considered the impact of local-scale downward migration of saline plumes in the topographic depressions on the NGFS. In this study, the classic NGFS are revisited by considering saline water in their discharge zones. To quantify the effects of salinity in the discharge zones on the NGFS, scenarios of various salinities in the discharge zones are simulated. The displacements of the internal stagnation points are used to quantify the evolution of the NGFS in response to salinity changes in the discharge zones. The results show that, as the salinity in the discharge zones increases, the hydraulic gradient near the discharge zone can be significantly reduced, the internal stagnation points shift upward, and the local groundwater flow systems retreat upward so that their original spaces are replaced by intermediate or regional flow systems. The discharge zone is expanded, and the overall groundwater flow velocity magnitude of the entire system decreases with salinity. This study may shed light on the management of saline wetlands, for example, the control of groundwater salinization, evolution of saline groundwater basins, and seawater intrusion.

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Numerical investigation of the combined effect of forced and free thermal convection in synthetic groundwater basins

Cited by 28 publications

References 55 publications

Groundwater flow system understanding of the lukewarm springs in Kistapolca (South Hungary) and its relevance to hypogene cave formation

Groundwater flow system understanding of the lukewarm springs in Kistapolca (South Hungary) and its relevance to hypogene cave formation

Numerical Analysis of the Groundwater Flow System and Heat Transport for Sustainable Water Management in a Regional Semi-Arid Basin in Central Mexico

Effects of Downward Intrusion of Saline Water on Nested Groundwater Flow Systems

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