Groundwater Velocity Research Articles

The Upwelling Water Flux Feeding Springs: Hydrogeological and Hydraulic Features

The upwelling groundwater flux has been investigated by deep piezometers in a spring area characterized by alluvial deposits covering a karst substratum in Southern Italy. The piezometers are of varying depth located in a flat area. They have been monitored for a long period (about 40 years), and when measured, a good relationship between spring discharge and hydraulic head was observed. The local upwelling groundwater flux has been deducted by the increasing of the hydraulic head in depth, which allows the estimation of ascendant hydraulic gradient and groundwater velocity during the dry and wet seasons. A specific analytical solution has been used to estimate the zone involved by the ascendant flow, and could also be used in other spring areas. Some physical and chemical characteristics of spring water have been collected, including the radon (222Rn) activity, to support the phenomenon of the ascendant flux. The man geological and hydrogeological features leading to ascendant flux in karst environments is also discussed for some areas of Southern Italy, where many springs are affected.

The impact of groundwater velocity fields on streamlines in an aquifer system with a discontinuous aquitard (Inner Mongolia, China)

Many numerical methods that simulate groundwater flow, particularly the continuous Galerkin finite element method, do not produce velocity information directly. Many algorithms have been proposed to improve the accuracy of velocity fields computed from hydraulic potentials. The differences in the streamlines generated from velocity fields obtained using different algorithms are presented in this report. The superconvergence method employed by FEFLOW, a popular commercial code, and some dual-mesh methods proposed in recent years are selected for comparison. The applications to depict hydrogeologic conditions using streamlines are used, and errors in streamlines are shown to lead to notable errors in boundary conditions, the locations of material interfaces, fluxes and conductivities. Furthermore, the effects of the procedures used in these two types of methods, including velocity integration and local conservation, are analyzed. The method of interpolating velocities across edges using fluxes is shown to be able to eliminate errors associated with refraction points that are not located along material interfaces and streamline ends at no-flow boundaries. Local conservation is shown to be a crucial property of velocity fields and can result in more accurate streamline densities. A case study involving both three-dimensional and two-dimensional cross-sectional models of a coal mine in Inner Mongolia, China, are used to support the conclusions presented.

Hydrogeological characterization of flow system in a karstic aquifer, Seymareh dam, Iran

In order to determine the characteristics of the flow system in a karstic aquifer, an extensive hydrogeological study includes dye tracing test was conducted. The aquifer suited left abutment of Seymareh Dam, in Ravandi Anticline and discharges by more than 50 springs in the southern flank. Flow system in the aquifer is mainly controlled by the reservoir of Seymareh Dam. Time variations of the spring discharge and water table in the observation wells were highly correlated with the reservoir water level. The average groundwater velocity ranges from 0.2 to more than 14 m/h based on the dye tracing test. The probable flow paths were differentiated in two groups including the flow paths in the northern and southern flanks of Ravandi Anticline. Types of groundwater flow in the proposed flow paths are determined as diffuse or conduit flow type considering groundwater velocity and shape of the breakthrough curves. An index is proposed for differentiation of diffuse and conduit flow system based on relationship of groundwater velocity and hydraulic gradient. Dominant geometry of the flow routs (e.g., conduit diameter and fracture aperture) is estimated for the groundwater flow paths toward the springs. Based on velocity variations and variance coefficient of the water table and discharge of springs on map view a major karst conduit was probably developed in the aquifer. This research emphasizes applying of an extensive hydrogeological study for characterization of flow system in the karst aquifer.

Transport of bacteriophage MS2 and PRD1 in saturated dune sand under suboxic conditions

Soil passage of (pretreated) surface water to remove pathogenic microorganisms is a highly efficient process under oxic conditions, reducing microorganism concentrations about 8 log10 within tens of meters. However, under anoxic conditions, it has been shown that removal of microorganisms can be limited very much. Setback distances for adequate protection of natural groundwater may, therefore, be too short if anoxic conditions apply. Because removal of microorganisms under suboxic conditions is unknown, this research investigated removal of bacteriophage MS2 and PRD1 by soil passage under suboxic conditions at field scale. At the field location (dune area), one injection well and six monitoring wells were installed at different depths along three suboxic flow lines, where oxygen concentrations ranged from 0.4 to 1.7 mg/l and nitrate concentrations ranged from 13 to 16 mg/L. PRD1 and MS2 were injected directly at the corresponding depths and their removal in each flow line was determined. The highest bacteriophage removal was observed in the top layer, with about 9 log removal of MS2, and 7 log removal of PRD1 after 16 meters of aquifer transport. Less removal was observed at 12 m below surface, probably due to a higher groundwater velocity in this coarser grained layer. MS2 was removed more effectively than PRD1 under all conditions. Due to short travel times, inactivation of the phages was limited and the reported log removal was mainly associated with attachment of phages to the aquifer matrix. This study shows that attachment of MS2 and PRD1 is similar for oxic and suboxic sandy aquifers, and, therefore, setback distances used for sandy aquifers under oxic and suboxic conditions provide a similar level of safety. Sticking efficiency and the attachment rate coefficient, as measures for virus attachment, were evaluated as a function of the physico-chemical conditions.

Application of new point measurement device to quantify groundwater-surface water interactions

The streambed point velocity probe (SBPVP) measures in situ groundwater velocities at the groundwater-surface water interface without reliance on hydraulic conductivity, porosity, or hydraulic gradient information. The tool operates on the basis of a mini-tracer test that occurs on the probe surface. The SBPVP was used in a meander of the Grindsted Å (stream), Denmark, to determine the distribution of flow through the streambed. These data were used to calculate the contaminant mass discharge of chlorinated ethenes into the stream. SBPVP data were compared with velocities estimated from hydraulic head and temperature gradient data collected at similar scales. Spatial relationships of water flow through the streambed were found to be similar by all three methods, and indicated a heterogeneous pattern of groundwater-surface water exchange. The magnitudes of estimated flow varied to a greater degree. It was found that pollutants enter the stream in localized regions of high flow which do not always correspond to the locations of highest pollutant concentration. The results show the combined influence of flow and concentration on contaminant discharge and illustrate the advantages of adopting a flux-based approach to risk assessment at the groundwater-surface water interface. Chlorinated ethene mass discharges, expressed in PCE equivalents, were determined to be up to 444 kg/yr (with SBPVP data) which compared well with independent estimates of mass discharge up to 438 kg/yr (with mini-piezometer data from the streambed) and up to 372 kg/yr crossing a control plane on the streambank (as determined in a previous, independent study).

Water Quality Assessment and Resource Potentials: the Case of Aba–Urban and its Environs, Niger Delta Basin

The quest for improved water supply to cater for the ever increasing population has given rise to the assessment of water quality and resource potentials in Aba-Urban and its environments. The area, which lies within the Niger Delta Basin is underlain by the Benin Formation that is highly aquiferous. Samples of sands and water were subjected to sedimentological and hydrochemical analysis, respectively. Result reveals that the aquifer is thick (over 100 m) and unconfined. The computed aquifer parameters indicate high yielding clean-sands with hydraulic conductivity values ranging from 1.13 × 10–4 to 5.70 × 10–3 m/s. The specific discharge is about 14.2 m/year while the average linear groundwater velocity is calculated to be 53.46 m/year. Hydrochemical investigations carried out on water samples from Aba River and the groundwater system revealed low dissolved geochemical constituents. Although, there is a slight increase from the north to the southern part along the flow path. In general, the groundwater is relatively enriched in Ca, Mg−HCO-3ions and is predominantly of bicarbonate constituents. However, in some places Cl− ions dominate over HCO-3ions. This is common where the water has come in contact with domestic sewage. This kind of contamination is also accompanied by elevated concentration of NO-3ions. Generally, the groundwater in most cases meets the standard for human consumption and is a better alternative to surface water. Consequently an increase exploitation of the prolific Benin aquifer through more hygienic and safe methods will surely be the best way of improving the domestic water supply situation in Aba City.

Condutividade hidráulica da formação rio claro a partir de ensaios granulométricos

A condutividade hidráulica (K) é um fator determinante em relação às características de um aquífero, permitindo (ou não) a transmissão de fluidos e influenciando, assim, na velocidade de fluxo em diferentes camadas geológicas. Dessa forma, constitui fator-chave na compreensão do fluxo de água e de contaminantes. Neste trabalho, a granulometria do Aquífero Rio Claro é utilizada para mais bem entender a distribuição de suas propriedades hidráulicas, em particular da condutividade hidráulica, obtida pelos métodos de Hazen, Shepherd e Krumbein & Monk. Os resultados foram comparados a testes de slug (Hvorslev) efetuados em poços existentes que exploram o aquífero. Verificou-se que a Formação Rio Claro apresenta grande variabilidade na relação areia/argila, sendo constituída por areias limpas, areias argilosas, até lentes silto-argilosas. A variabilidade granulométrica é grande próximo ao contato com a Formação Corumbataí, com mudanças marcantes nas quantidades de argila, silte e areia fina, além de contribuição expressiva de grânulos. Essa variabilidade litológica influencia na distribuição da condutividade hidráulica, cujos valores variam entre 8 x 10-3 cm/s e 2 x 10-3 cm/s em arenitos e são cerca de duas a três ordens de grandeza menores em lamitos. Os arenitos da Formação Rio Claro, apesar de espessuras restritas, possuem alta condutividade hidráulica, constituindo um ótimo reservatório de águas subterrâneas; porém, a presença de espessas lentes de argila pode atuar como barreiras hidráulicas. Desse modo, esta unidade aquífera tem o seu potencial de explotação subordinado à presença e continuidade espacial de camadas de arenitos com pouca matriz.

Contribution of spectral coherency analysis and tracer test to study leakage at the Doosti Dam reservoir, Iran and Turkmenistan

The Doosti Dam was built across the Harirood River on the border between Turkmenistan and Iran. During the reservoir impounding, leakage occurred as new springs through the sandstone layers of the Pesteleigh Aquifer and limy sandstone and limestone layers of the Neyzar–Kalat Aquifer, at the right abutment of the dam. To evaluate the grout curtain operation, a tracer test was carried out by injection of Uranine in a borehole located at the upstream of grout curtain in the Pesteleigh Aquifer. Tracer test results demonstrated a diffuse flow component through the grout curtain in the Pesteleigh Aquifer, but no tracer was detected at the main leakage point, SP1 Spring, emerged downstream of grout curtain from the Neyzar–Kalat Aquifer. Using the spectral coherency function, the lag time between changes in the water level of the injection borehole and water level in the tracer detected boreholes or discharge of the tracer detected springs was determined. Linear regression analyses indicated that the estimated lag time by the time series analysis was close to the first arrival time of the tracer. Therefore, the estimated velocities based on the lag time of time series could be considered close to the calculated velocities based on the first arrival time of the tracer. The estimated groundwater velocities based on the time series analysis ranged from 3.91 to 20.31 m h−1, showed that diffuse flow dominated pathways from the reservoir toward the downstream boreholes in the Neyzar–Kalat Aquifer, while conduit flow was present within the pathways toward the SP1 Spring. Regarding the reservoir volume, the negligible amount of leakage at the maximum water level of the reservoir confirmed well overall operation of the grout curtain at the dam site.

Estimating transverse dispersivity based on hydraulic conductivity

Abstract The modeling of depletion timeframe for a non-aqueous phase liquid (NAPL) layer is partially dependent on transverse vertical dispersivity. This paper provides guidance for estimating this parameter over the wide range of soil textures in which NAPL resides at contaminated sites. Transverse dispersivity is re-calculated for several previous NAPL dissolution studies based on a consistent methodology for estimating model input parameters. Through the compilation of a number of case studies from the literature including multiple NAPL dissolution experiments, the trend of transverse vertical dispersivity appears to be inversely proportional to the effective grain diameter when groundwater velocity (v) is below a critical threshold ( v c ). A novel regression equation is derived for estimating transverse dispersivity based on hydraulic conductivity when v v c and the NAPL length is on the order of meters. The critical velocity for NAPL pool dissolution appears to range from 3 to 5 m/d based on a limited number of studies with NAPL pool lengths of 1 m or more. The method derived by Klenk and Grathwohl (2002) is validated for estimating a correction factor for dispersivity when v > v c .

Analytical solution of two-dimensional advection–dispersion equation with spatio-temporal coefficients for point sources in an infinite medium using Green’s function method

In the present study analytical solutions of a two-dimensional advection–dispersion equation (ADE) with spatially and temporally dependent longitudinal and lateral components of the dispersion coefficient and velocity are obtained using Green’s Function Method (GFM). These solutions describe solute transport in infinite horizontal groundwater flow, assimilating the spatio-temporal dependence of transport properties, dependence of dispersion coefficient on velocity, and the particulate heterogeneity of the aquifer. The solution is obtained in the general form of temporal dependence and the source term, from which solutions for instantaneous and continuous point sources are derived. The spatial dependence of groundwater velocity is considered non-homogeneous linear, whereas the dispersion coefficient is considered proportional to the square of spatial dependence of velocity. An asymptotically increasing temporal function is considered to illustrate the proposed solutions. The solutions are validated with the existing solutions derived from the proposed solutions in three special cases. The effect of spatially/temporally dependent heterogeneity on the solute transport is also demonstrated. To use the GFM, the ADE with spatio-temporally dependent coefficients is reduced to a dispersion equation with constant coefficients in terms of new position variables introduced through properly developed coordinate transformation equations. Also, a new time variable is introduced through a known transformation.

Discussion of the pipe flow model to analyze the critical parameter of seepage erosion forming sinkholes in Liuzhou, China

On May 10th, 2012, 41 sinkholes collapsed the southern suburbs of Liuzhou, Guangxi Province, China, damaging 143 houses, eight factories buildings, and three commercial buildings. Lei (2013) revealed that groundwater dynamics, contributed to by the daily rainfall of 169.7 mm, led to soil particles running off (seepage erosion) resulting in the sinkholes. It is crucial to identify the critical parameters of seepage erosion that forms sinkholes. This paper analyzes critical parameters in the study site, establishes the pipe flow model of seepage erosion, and deduces parameter expression using its theories. We devised experimental equipment designed to simulate the process of seepage erosion and test the critical shear stress (τcr) of soil samples from the field. Additionally, we measured the diameter (d) of pores in the field soil using a scanning electron microscope, and calculated the critical groundwater velocity (Vcr). As the result, we found that the collapsed sinkholes in the study site were formed by groundwater with a velocity of 7.652 × 10−5 m/s (or 0.459 cm/min).

Contribution to the Ground Water Hydrology of the Quaternary Aquifer in West Ismailia Area, Egypt

Hydrologic conditions of the ground water of the Quaternary aquifer in west Ismailia area, Egypt, were characterized based on new hydrologic data collected in 2017. The Quaternary aquifer consists of alluvial deposits. The grain size distribution results indicate that the major part of the aquifer deposits is formed of medium to coarse grained sand with medium uniformity coefficients ranging between 2.5 and 10. They also reflect the heterogeneity, anisotropy and high productivity of the aquifer. The estimated aquifer parameters range from 29% to 41% for total porosity, from 18.71 m/day to 63.95 m/day for horizontal hydraulic conductivity, from 8.94 m/day to 61.6 m/day for vertical hydraulic conductivity, from 1.01 to 4.27 for anisotropy and from 1870 m2/day to 6549 m2/day for transmissivity. The ground water flows mainly from the north and northeast recharge sources (Ismailia and El Manaief canals) and from the south recharge area (Miocene aquifer), with an average hydraulic gradient of 0.00438. The recharge rate to the aquifer (from the southern area) and the Darcy’s velocity of ground water are estimated to be 447 × 106 m3/year and 0.203 m/day (on average), respectively. A great change in the hydrologic setting of the aquifer is occurred during the period of 1992-2017, where the groundwater flow has changed during that period. The aquifer contains fresh to saline water. An oxidizing (alkaline) environment is reported for the aquifer, as revealed from the relationship between the redox potential (185 - 836 mV) and pH (5.2 - 7.5 standard units). This indicated the capability of ground water to dissolve heavy metals associated to rock-forming minerals. A wide variation in the concentrations of total dissolved solids (320 - 7385 mg/l) and dissolved oxygen (2.13 - 8.4 mg/l) in the Quaternary aquifer is observed, reflecting the local variation of the environmental and geologic conditions and indicating the influence of different recharge sources.

Assessment of Groundwater Potential of Gandhinagar Region, Gujarat

ABSTRACT With burgeoning population, the groundwater demands of any area increased by many fold and therefore, it is essential to assess the groundwater potential to choose suitable sites for further groundwater development. Present study determines the groundwater potential of different parts of Gandhinagar region located at Gandhinagar district, Gujarat, India. Here, excluding city dwellers, all villagers are mostly dependent on groundwater for drinking and domestic purposes. With increasing population, there is a rise in daily human consumption and hence reduction in groundwater quantity. Various types of industries of Gandhinagar such as textile industries, food processing industries, ceramic industries etc. also require groundwater. Industrial discharges deteriorate the water quality of this region. Therefore, water level monitoring and quality assessment of groundwater in regular intervals is essential. The groundwater potential zoning is an indicator, which gives the overall idea about the groundwater condition. Overlay analysis in GIS using multiple criteria such as WQI, hydraulic conductivity, groundwater velocity, and depth to piezometric surface discloses that there are five groundwater potential zones in Gandhinagar region. This study reveals that majority of the study area is covered with medium potential zone. Different management plans such as treated surface water supply, reduction in tubewell operation time, development of rooftop rainwater harvesting system and artificial recharge system etc. are recommended for different potential zones for sustainable development of groundwater of Gandhinagar region.

Evaluation of the Potential for Dissolved Oxygen Ingress into Deep Sedimentary Basins during a Glaciation Event

Geochemical conditions in intracratonic sedimentary basins are currently reducing, even at relatively shallow depths. However, during glaciation-deglaciation events, glacial meltwater production may result in enhanced recharge (Bea et al., 2011; and Bea et al., 2016) potentially having high concentrations of dissolved oxygen (O2). In this study, the reactive transport code Par-MIN3P-THCm was used to perform an informed, illustrative set of simulations assessing the depth of penetration of low salinity, O2-rich, subglacial recharge. Simulation results indicate that the large-scale basin hydrostratigraphy, in combination with the presence of dense brines at depth, results in low groundwater velocities during glacial meltwater infiltration, restricting the vertical ingress of dilute recharge waters. Furthermore, several geochemical attenuation mechanisms exist for O2, which is consumed by reactions with reduced mineral phases and solid organic matter (SOM). The modeling showed that effective oxidative mineral dissolution rates and SOM oxidation rates between 5 × 10−15 and 6 × 10−13 mol dm−3 bulk s−1 were sufficient to restrict the depth of O2 ingress to less than 200 m. These effective rates are low and thus conservative, in comparison to rates reported in the literature. Additional simulations with more realistic, yet still conservative, parameters reaffirm the limited ability for O2 to penetrate into sedimentary basin rocks during a glaciation-deglaciation event.

Estimation of groundwater flow from temperature monitoring in a borehole heat exchanger during a thermal response test

To estimate the groundwater flow around a borehole heat exchanger (BHE), thermal properties of geological core samples were measured and a thermal response test (TRT) was performed in the Tsukuba upland, Japan. The thermal properties were measured at 57 points along a 50-m-long geological core, consisting predominantly of sand, silt, and clay, drilled near the BHE. In this TRT, the vertical temperature in the BHE was also monitored during and after the test. Results for the thermal properties of the core samples and from the monitoring indicated that groundwater flow enhanced thermal transfers, especially at shallow depths. The groundwater velocities around the BHE were estimated using a two-dimensional numerical model with monitoring data on temperature changes. According to the results, the estimated groundwater velocity was generally consistent with hydrogeological data from previous studies, except for the data collected at shallow depths consisting of a clay layer. The reasons for this discrepancy at shallow depths were predicted to be preferential flow and the occurrence of vertical flow through the BHE grout, induced by the hydrogeological conditions.

Numerical groundwater modelling in karst

Abstract The success of translating a conceptual site model for a karst site into a numerical groundwater model will depend on both the experience of the user and the capabilities and limitations of the selected computer program. Despite its numerous advantages, even MODFLOW – probably the most widely used, tested and verified modelling program currently available – has conceptual limitations that many karst hydrogeologists have to deal with on a routine basis while searching for an equivalent porous medium approach that may work. This includes assigning very high values of hydraulic conductivity to those model cells known, or suspected, to contain highly transmissive conduits, or assigning an unreasonable, very low effective porosity to the model cells with virtual ‘conduits’ to simulate high groundwater velocities. A new version of MODFLOW called MODFLOW-USG (UnStructured Grid) has been developed and released to the public domain. This new version retains full compatibility with previous versions of MODFLOW while taking advantage of unstructured grids and finite volume numerical solutions. It enables hydrogeologists to accurately translate even the most complex conceptual site models in karst into a numerical environment, thus eliminating the need for various surrogate modelling solutions based on an equivalent porous medium approach.

Contaminant back-diffusion from low-permeability layers as affected by groundwater velocity: A laboratory investigation by box model and image analysis

Low-permeability lenses represent potential sources of long-term release when filled from contaminant solute through direct contact with dissolved plumes. The redistribution of contaminant from low to high permeability aquifer zones (Back-Diffusion) was studied. Redistribution causes a long plume tail, commonly regarded as one of the main obstacles to effective groundwater remediation. Laboratory tests were performed to reproduce the redistribution process and to investigate the effect of pumping water on the remediation time of these contaminated low-permeability lenses. The test section used is representative of clay/silt lenses (k≈1∗10−10m/s/k≈1∗10−7m/s) in a sand aquifer (k≈1∗10−3m/s). Hence, an image analysis procedure was used to estimate the diffusive flux of contaminant released by these low-permeability zones. The proposed technique was validated performing a mass balance of a lens saturated by a known quantity of tracer. For each test, performed using a different groundwater velocity, the diffusive fluxes of contaminant released by lenses were compared and the remediation times of the low-permeability zones calculated. For each lens, the obtained remediation timeframes were used to define an analytical relation vs groundwater velocity and the coefficients of these relations were matched to grain size of the low-permeability lenses. Results show that an increase of the velocity field is not useful to diminish the total depletion times as the process mainly diffusive. This is significant when the remediation approach relies on pumping technology.

An In-Well Point Velocity Probe for the rapid determination of groundwater velocity at the centimeter-scale

The In-Well Point Velocity Probe (IWPVP) is a novel device designed for obtaining rapid, initial measurements of groundwater velocity at the centimeter-scale using a standard monitoring well to access the subsurface. IWPVP measurements of groundwater speed are quantified on the basis of a mini-tracer test that is conducted within the body of the probe. Information regarding horizontal flow directions is obtained from differential responses at detectors placed in the four quadrants of the probe. The viability of the IWPVP design was confirmed by (1) numerical modeling that accounted for laminar flow in the porous medium outside the well and turbulent flow inside the well (and probe), and (2) a series of laboratory tank experiments in which the probe was calibrated to quantify seepage rates in a medium-grain sand. Laboratory tests were completed in less than 20 min in all cases, when seepage velocity was between 50 and 400 cm/day. The magnitude of the groundwater velocity was determined with a precision of ±7% on average, and accuracy of ±11% for seepage velocities up to 400 cm/day. The flow direction was determined within ±15°. The IWPVP appears to be a viable tool for rapid assessment of groundwater velocity.

Time-lapse Mise-á-la-Masse measurements and modeling for tracer test monitoring in a shallow aquifer

The main goal of this study is to evaluate the reliability of the Mise-á-la-Masse (MALM) technique associated with saline tracer tests for the characterization of groundwater flow direction and velocity. The experimental site is located in the upper part of the Alento River alluvial plain (Campania Region, Southern Italy). In this paper we present the hydrogeological setting, the experimental setup and the relevant field results. Subsequently, we compare those data against the simulated results obtained with a 3D resistivity model of the test area, coupled with a model describing the Advection – Dispersion equation for continuous tracer injection. In particular, we calculate a series of 3D forward solutions starting from a reference model, all derived from electrical tomography results, but taking into consideration different values of mean flow velocity and directions. Each electrical resistivity 3D model is used to produce synthetic voltage maps for MALM surveys. Finally, the synthetic MALM voltage maps are compared with the ones measured in the field in order to assess the information content of the MALM dataset with respect to the groundwater field characteristics. The results demonstrate that the information content of the MALM data is sufficient to define important characteristics of the aquifer geometry and properties. This work shows how a combination of three-dimensional time-lapse modeling of flow, tracer transport and electrical current can substantially contribute towards a quantitative interpretation of MALM measurements during a saline tracer test. This approach can thus revive the use of MALM as a practical, low cost field technique for tracer test monitoring and aquifer hydrodynamic characterization.

Multilayer analytical model for vertical ground heat exchanger with groundwater flow

The vertical ground heat exchangers (GHE) are the most common application of the ground source heat pump (GSHP) systems. Due to ground heterogeneity and length of the boreholes, the heat exchangers cross usually several geological layers. However, in most of the current analytical models for GHEs, the restrictive assumption of ground homogeneity is considered. In this paper, a finite line-source model is proposed for GHEs that takes into account not only thermal conduction but also advection and dispersion mechanisms, induced by ground water flow, in a multilayer porous medium. Firstly, the anisotropy is added to the moving finite line-source (MFLS) model, and an existing composite model approach is modified. The temperature comparison with the numerical model results demonstrates the suitability of the approach. The proposed model provides faster solution than typical 3D numerical methods Furthermore, the homogeneous and multilayer assumptions are analyzed in dimensionless form to check the convenience of both of the approaches. The results demonstrate that, in case of high groundwater velocity in one layer, the thermal interaction with the neighboring layers decreases due to strong groundwater flow suppressing the thermal flux interaction. In that case, the prediction of homogeneous assumption is slightly sufficient in the middle of the layer. Otherwise, the multilayer approach is more appropriate in transient conditions, particularly, at the interface of layers.