Journal articles on the topic 'Hydrogeological and transport modeling'

To see the other types of publications on this topic, follow the link: Hydrogeological and transport modeling.

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Hydrogeological and transport modeling.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Shabani, Babak, Peng Lu, Ryan Kammer, and Chen Zhu. "Effects of Hydrogeological Heterogeneity on CO2 Migration and Mineral Trapping: 3D Reactive Transport Modeling of Geological CO2 Storage in the Mt. Simon Sandstone, Indiana, USA." Energies 15, no. 6 (March 16, 2022): 2171. http://dx.doi.org/10.3390/en15062171.

Full text
Abstract:
We used three-dimensional (3D), high-resolution simulations facilitated by parallel computation to assess the effect of hydrogeological heterogeneity in the Mt. Simon Sandstone on CO2 plume evolution and storage and geochemical reactions in a portion of the Illinois Basin, Indiana. Two scenarios were selected to investigate the effects of the hydrogeological heterogeneity in 3D reactive transport simulations: a heterogeneous case with variable porosity and permeability, and a homogenous case with constant porosity and permeability. The initial pressure, temperature, and mineralogical distributions are consistently applied in both the heterogeneous case and the homogeneous case. Results indicate that including hydrogeological heterogeneity in 3D reservoir simulations for geological CO2 storage significantly impacts modeling results for plume migration patterns, CO2-water-mineral interaction, reservoir quality, and CO2 plume containment. In particular, results indicate that (1) the CO2 plume reached the top of the Mt. Simon Sandstone in the homogeneous case, but was restrained to the lower third of the formation when hydrogeologic heterogeneity was considered; (2) the dominant trapping mechanism in the heterogeneous case was mineral trapping (43%), while it was solubility trapping (47%) in the homogeneous case (at 10,000 years); (3) incorporating reservoir heterogeneity in the model leads to a higher likelihood of long-term containment.
APA, Harvard, Vancouver, ISO, and other styles
2

Stoyanov, Nikolay. "Mass-transport modeling of a fast-moving contaminant in the subsurface area of industrial sites." Engineering Geology and Hydrogeology 32, no. 1 (2018): 13–22. http://dx.doi.org/10.52321/igh.32.1.13.

Full text
Abstract:
The conditions for spreading of a fast-moving contaminant in the subsurface were studied at an industrial site where large amounts of contaminated water had been discharged over a relatively long period of time. The site is located in the eastern part of the town of Karlovo in Southern Bulgaria. Several hydrogeological units were distinguished in the near-surface following the application of hydrogeological methods and techniques, including investigative drilling, slug tests and laboratory tracer tests. Two-dimensional (2D) mathematical models were used to simulate the mass-transport of a fast-moving contaminant in the unsaturated and saturated zones. A deterministic modelling approach was applied in simulating the established hydrogeological units. Each unit was represented as a two-dimensional object with distinct boundaries and properties. The models were set up using VS2DTI software simulating convective mass transport, reversible elimination (sorption/ desorption), hydrodynamic dispersion, molecular diffusion and mixing. The models were used for predicting the contaminant migration from a continuous source on the surface to a depth of 15-20 m. Different model solutions were used to assess the protective effect of the man-made cover and subsurface geology at the industrial site.
APA, Harvard, Vancouver, ISO, and other styles
3

Hajrah, Ardy Arsyad, and Achmad Zubair. "Modeling of Contaminant Transport and Groundwater Flow of Tamangapa Landfill in Makassar Indonesia." Applied Mechanics and Materials 567 (June 2014): 92–97. http://dx.doi.org/10.4028/www.scientific.net/amm.567.92.

Full text
Abstract:
This paper aims to analyze the groundwater flow direction of Tamangapa landfill and to predict the contaminant in the groundwater over the period of 20 years, accounted for the year of 2000 until 2020. To understand the natural condition of the landfill, geological and hydrogeological survey were undertaken, consisting of geological survey, geomorphology and geo-resistivity surveys. Hydrogeological survey comprises groundwater level measurement, chemical analysis of leachate and groundwater samples which were later used as input data for numerical model. Based on the result of groundwater flow models, the direction of groundwater is found to be flowing from the north to the south. The minimum concentration for manganese (Mn) is 1.519 mg/l and 2.701 mg/l for iron (Fe). Over the period of 2020, Fe concentration increases significantly, reaching the level of 56.427 mg/l, Mn concentration for 299.5594 mg/l. It can be suggested that the groundwater quality of Tamangapa landfill has already exceeded the standard for water quality, leading to potential severe impact to local people around the landfill. Keywords: Landfill, modflow, groundwater, leachate, contaminant.
APA, Harvard, Vancouver, ISO, and other styles
4

Balint, Alexandru. "Geological and hydrogeological characterization of the landfill areas located around Bucharest city in the context of environmental management." MATEC Web of Conferences 342 (2021): 03015. http://dx.doi.org/10.1051/matecconf/202134203015.

Full text
Abstract:
The process of risk assessment and investigation of potentially contaminated soil and groundwater is highly dependent on a proper understanding of the geological and hydrogeological conditions of the investigated site. The current paper aims at identifying the general geological and hydrogeological conditions of the landfill areas around Bucharest city based on interpretations of the data available in research articles, books, public reports, and geological and hydrogeological maps. Several soil samples were collected, and laboratory analyses were conducted to validate the initial expectations in terms of physical properties of the underlying strata. Results were presented as cross-sections and piezometric maps suitable for developing tridimensional models, conceptual site models and contaminant fate and transport modeling with sufficient accuracy for environmental urban planning. The research provides a quick method which may be used when assessing the general geological and hydrogeological conditions of various sites in environmental studies. The vulnerability of the Romanian legislation in data management and decision-making was also highlighted, therefore a series of recommendations to improve the data availability and quality were provided.
APA, Harvard, Vancouver, ISO, and other styles
5

Hermans, Thomas, Pascal Goderniaux, Damien Jougnot, Jan H. Fleckenstein, Philip Brunner, Frédéric Nguyen, Niklas Linde, et al. "Advancing measurements and representations of subsurface heterogeneity and dynamic processes: towards 4D hydrogeology." Hydrology and Earth System Sciences 27, no. 1 (January 12, 2023): 255–87. http://dx.doi.org/10.5194/hess-27-255-2023.

Full text
Abstract:
Abstract. Essentially all hydrogeological processes are strongly influenced by the subsurface spatial heterogeneity and the temporal variation of environmental conditions, hydraulic properties, and solute concentrations. This spatial and temporal variability generally leads to effective behaviors and emerging phenomena that cannot be predicted from conventional approaches based on homogeneous assumptions and models. However, it is not always clear when, why, how, and at what scale the 4D (3D + time) nature of the subsurface needs to be considered in hydrogeological monitoring, modeling, and applications. In this paper, we discuss the interest and potential for the monitoring and characterization of spatial and temporal variability, including 4D imaging, in a series of hydrogeological processes: (1) groundwater fluxes, (2) solute transport and reaction, (3) vadose zone dynamics, and (4) surface–subsurface water interactions. We first identify the main challenges related to the coupling of spatial and temporal fluctuations for these processes. We then highlight recent innovations that have led to significant breakthroughs in high-resolution space–time imaging and modeling the characterization, monitoring, and modeling of these spatial and temporal fluctuations. We finally propose a classification of processes and applications at different scales according to their need and potential for high-resolution space–time imaging. We thus advocate a more systematic characterization of the dynamic and 3D nature of the subsurface for a series of critical processes and emerging applications. This calls for the validation of 4D imaging techniques at highly instrumented observatories and the harmonization of open databases to share hydrogeological data sets in their 4D components.
APA, Harvard, Vancouver, ISO, and other styles
6

Iversen, Bo V., Peter van der Keur, and Henrik Vosgerau. "Hydrogeological Relationships of Sandy Deposits: Modeling of Two-Dimensional Unsaturated Water and Pesticide Transport." Journal of Environmental Quality 37, no. 5 (September 2008): 1909–17. http://dx.doi.org/10.2134/jeq2006.0200.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Székely, Ferenc, József Deák, Péter Szűcs, László Kompár, Balázs Zákányi, and Mihály Molnár. "Verification of Radiocarbon Transport Predicted by Numerical Modeling in the Porous Formation of NE Hungary Considering Paleo-Hydrogeology." Radiocarbon 62, no. 1 (July 24, 2019): 219–33. http://dx.doi.org/10.1017/rdc.2019.84.

Full text
Abstract:
ABSTRACTVerification of a groundwater flow model by radiocarbon (14C) data are presented taking into consideration the paleo-hydrogeological changes. Northeastern area of the Great Hungarian Plain was a deep-lying flat area, and its central part (Nyírség) has been uplifted in the last 15,000 years. These geological events have drastically changed the hydrogeological conditions of Nyírség. The groundwater flow system is composed of the Quaternary-Pliocene-Upper Pannonian clastic sediments. Groundwater flow modeling has been performed to define the main lateral and vertical flow directions and velocities controlling the propagation of the environmental radioactive tracer 14C. Solute-transport modeling was used to calculate the 14C activity. The recent steady-state groundwater flow velocity was reduced to a reasonable value characterizing the average flow velocity over the 15 ka simulation period using “trial and error” method. The best fit between the simulated and measured 14C data was achieved by assuming 0.4 flow velocity reduction factor. Results indicate that the present steady-state flow model with this flow velocity reduction factor is capable of reproducing the observed 14C data taking into account the effect of the significant uplift of the part of the land surface in the last 15 ka in NE Hungary.
APA, Harvard, Vancouver, ISO, and other styles
8

Patel, Sharad. "Advances in Inverse Groundwater Modeling: A Comprehensive Review." International Journal of Current Microbiology and Applied Sciences 12, no. 12 (December 10, 2023): 83–100. http://dx.doi.org/10.20546/ijcmas.2023.1212.012.

Full text
Abstract:
The management and sustainable use of groundwater resources are critical components in addressing global water challenges. In this context, inverse groundwater modeling has emerged as a powerful tool for characterizing subsurface properties, optimizing resource utilization, and mitigating the impacts of anthropogenic activities on aquifers. This review paper provides a comprehensive and up-to-date survey of the advancements in inverse groundwater modeling techniques, methodologies, and applications. The paper begins by presenting an overview of the fundamental principles underlying inverse modeling, elucidating the mathematical frameworks and numerical algorithms employed in estimating subsurface parameters. It explores various geophysical and hydrogeological data types commonly utilized in inverse modeling, such as hydraulic head measurements, and geophysical surveys. The integration of multiple data sources for enhancing model reliability and reducing uncertainty is also discussed. Furthermore, the review highlights recent developments in regularization techniques, sensitivity analysis, and uncertainty quantification within the context of inverse groundwater modeling. Case studies from diverse hydrogeological settings illustrate the practical applications of these methodologies in real-world scenarios, showcasing their efficacy in addressing complex groundwater management challenges, including contaminant transport, aquifer recharge, and sustainable resource exploitation. The review concludes by outlining current research gaps and future directions in the field of inverse groundwater modeling, emphasizing the need for interdisciplinary collaboration, data integration, and advanced computational approaches. This synthesis of contemporary knowledge serves as a valuable resource for researchers, practitioners, and policymakers engaged in groundwater management and environmental sustainability.
APA, Harvard, Vancouver, ISO, and other styles
9

Bui, Minh Tuan, Jinmei Lu, and Linmei Nie. "A Review of Hydrological Models Applied in the Permafrost-Dominated Arctic Region." Geosciences 10, no. 10 (October 6, 2020): 401. http://dx.doi.org/10.3390/geosciences10100401.

Full text
Abstract:
The Arctic region is the most sensitive region to climate change. Hydrological models are fundamental tools for climate change impact assessment. However, due to the extreme weather conditions, specific hydrological process, and data acquisition challenges in the Arctic, it is crucial to select suitable hydrological model(s) for this region. In this paper, a comprehensive review and comparison of different models is conducted based on recently available studies. The functionality, limitations, and suitability of the potential hydrological models for the Arctic hydrological process are analyzed, including: (1) The surface hydrological models Topoflow, DMHS (deterministic modeling hydrological system), HBV (Hydrologiska Byråns Vattenbalansavdelning), SWAT (soil and water assessment tool), WaSiM (water balance simulation model), ECOMAG (ecological model for applied geophysics), and CRHM (cold regions hydrological model); and (2) the cryo-hydrogeological models ATS (arctic terrestrial simulator), CryoGrid 3, GEOtop, SUTRA-ICE (ice variant of the existing saturated/unsaturated transport model), and PFLOTRAN-ICE (ice variant of the existing massively parallel subsurface flow and reactive transport model). The review finds that Topoflow, HBV, SWAT, ECOMAG, and CRHM are suitable for studying surface hydrology rather than other processes in permafrost environments, whereas DMHS, WaSiM, and the cryo-hydrogeological models have higher capacities for subsurface hydrology, since they take into account the three phase changes of water in the near-surface soil. Of the cryo-hydrogeological models reviewed here, GEOtop, SUTRA-ICE, and PFLOTRAN-ICE are found to be suitable for small-scale catchments, whereas ATS and CryoGrid 3 are potentially suitable for large-scale catchments. Especially, ATS and GEOtop are the first tools that couple surface/subsurface permafrost thermal hydrology. If the accuracy of simulating the active layer dynamics is targeted, DMHS, ATS, GEOtop, and PFLOTRAN-ICE are potential tools compared to the other models. Further, data acquisition is a challenging task for cryo-hydrogeological models due to the complex boundary conditions when compared to the surface hydrological models HBV, SWAT, and CRHM, and the cryo-hydrogeological models are more difficult for non-expert users and more expensive to run compared to other models.
APA, Harvard, Vancouver, ISO, and other styles
10

Vallner, L., and A. Porman. "Groundwater flow and transport model of the Estonian Artesian Basin and its hydrological developments." Hydrology Research 47, no. 4 (February 8, 2016): 814–34. http://dx.doi.org/10.2166/nh.2016.104.

Full text
Abstract:
The sophisticated research and management problems of the Estonian water environment are considered by means of holistic modelling. The model elaborated is based on the computer code Visual MODFLOW Classic. The model encompasses the entire Estonian Artesian Basin (EAB) and the border districts of Russia and Latvia. It involves all main aquifers and aquitards on an area of 88,000 km2. The main hydrogeological and hydrological characteristics of the study area, including the time-dependent three-dimensional distribution of groundwater heads, the direction, velocity and rate of subsurface fluxes, itemised water budgets, volumes of hydrogeological units, and durations of groundwater exchange have been determined by modelling. The palaeohydrological situation during the last continental glaciation of the EAB was reconstructed and the principal problems of the sustainable management of water environment were elucidated. The model has been used to simulate the local and cumulative rates of the base flow.
APA, Harvard, Vancouver, ISO, and other styles
11

Molinero, Jorge, Juan R. Raposo, Juan M. Galíndez, David Arcos, and Jordi Guimerá. "Coupled hydrogeological and reactive transport modelling of the Simpevarp area (Sweden)." Applied Geochemistry 23, no. 7 (July 2008): 1957–81. http://dx.doi.org/10.1016/j.apgeochem.2008.02.020.

Full text
APA, Harvard, Vancouver, ISO, and other styles
12

Hałaj, Elżbieta. "Finite element modeling of geothermal source of heat pump in long-term operation." E3S Web of Conferences 154 (2020): 04003. http://dx.doi.org/10.1051/e3sconf/202015404003.

Full text
Abstract:
Heat pumps become more and more popular heat source. They can be an alternative choice for obsolete coal fired boilers which are emissive and not ecological. During heat pump installation designing process, especially for heat pumps with higher heating capacity (for example those suppling larger buildings), a simulation of heat balance of ground heat source must be provided. A 3D heat transport model and groundwater flow in the geothermal heat source for heat pump (GSHP) installation was developed in FEFLOW according to Finite Element Modelling Method. The model consists of 25 borehole heat exchangers, arranged with spacing recommended by heat pump branch guidelines. The model consists of both a homogeneous, non-layered domain and a layered domain, which reflected differences in thermal properties of the ground and hydrogeological factors. The initial temperature distribution in the ground was simulating according to conditions typical for Europe in steady state heat flow. Optimal mesh refinement for nodes around borehole heat exchangers were calculated according to Nillert method. The aim of this work is to present influence of geological, hydrogeological factors and borehole arrangement in the energy balance and long term sustainability of the ground source. The thermal changes in the subsurface have been determined for a long term operation (30 years of operation period). Some thermal energy storage applications have also been considered.
APA, Harvard, Vancouver, ISO, and other styles
13

Sieczka, Anna, Filip Bujakowski, and Eugeniusz Koda. "Modelling groundwater flow and nitrate transport: a case study of an area used for precision agriculture in the middle part of the Vistula River valley, Poland." Geologos 24, no. 3 (December 1, 2018): 225–35. http://dx.doi.org/10.2478/logos-2018-0023.

Full text
Abstract:
Abstract The present paper discusses studies related to the preparation of a hydrogeological model of groundwater flow and nitrate transport in an area where a precision farming system is applied. Components of water balance were determined using the UnSat Suite Plus software (HELP model), while the average infiltration rate calculated for the study area equalled 20 per cent. The Visual MODFLOW software was used for the purpose of modelling in the saturated zone. Hydrogeological parameters of the model layers, inclusive of hydraulic conductivity, were defined on the basis of results of column tests that were carried out under laboratory conditions (column experiment). Related to the dose of mineral nitrogen used in precision fertilisation (80 kg N/ha), scenarios of the spread of nitrates in the soil-water environment were worked out. The absolute residual mean error calculated for nitrate concentrations obtained from laboratory and modelling studies equalled 0.188 mg/L, the standard error of the estimate equalling 0.116 mg/L. Results obtained were shown graphically in the form of hydroisohypse maps and nitrate isolines. Conclusions were drawn regarding the possibility of using numerical modelling techniques in predicting transport and fate of nitrates from fertilisers applied in precision agriculture systems.
APA, Harvard, Vancouver, ISO, and other styles
14

Wu, Xiange, Tiantian Ye, Chunsheng Xie, Kun Li, Chang Liu, Zhihui Yang, Rui Han, Honghua Wu, and Zhenxing Wang. "Experimental and Modeling Study on Cr(VI) Migration from Slag into Soil and Groundwater." Processes 10, no. 11 (October 31, 2022): 2235. http://dx.doi.org/10.3390/pr10112235.

Full text
Abstract:
The transport and prediction of hexavalent chromium (Cr(VI)) contamination in “slag–soil–groundwater” is one with many uncertainties. Based on the column experiments, a migration model for Cr(VI) in the slag–soil–groundwater system was investigated. The hydraulic conductivity (Kt), distribution coefficient (Kd), retardation factor (Rd), and other hydraulic parameters were estimated in a laboratory. Combining these hydraulic parameters with available geological and hydrogeological data for the study area, the groundwater flow and Cr(VI) migration model were developed for assessing groundwater contamination. Subsequently, a Cr(VI) migration model was developed to simulate the transport of Cr(VI) in the slag–soil–groundwater system and predict the effect of three different control programs for groundwater contamination. The results showed that the differences in the measured and predicted groundwater head values were all less than 3 m. The maximum and minimum differences in Cr(VI) between the measured and simulated values were 1.158 and 0.001 mg/L, respectively. Moreover, the harmless treatment of Cr(VI) slag considerably improved the quality of groundwater in the surrounding areas. The results of this study provided a reliable mathematical model for transport process analysis and prediction of Cr(VI) contamination in a slag–soil–groundwater system.
APA, Harvard, Vancouver, ISO, and other styles
15

Huysmans, Marijke, and Alain Dassargues. "Hydrogeological modeling of radionuclide transport in low permeability media: a comparison between Boom Clay and Ypresian Clay." Environmental Geology 50, no. 1 (February 14, 2006): 122–31. http://dx.doi.org/10.1007/s00254-006-0191-7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
16

Mohanadhas, Berlin, and Suresh Kumar Govindarajan. "Modeling the sensitivity of hydrogeological parameters associated with leaching of uranium transport in an unsaturated porous medium." Environmental Engineering Research 23, no. 4 (May 11, 2018): 462–73. http://dx.doi.org/10.4491/eer.2017.113.

Full text
APA, Harvard, Vancouver, ISO, and other styles
17

Radha, Rashmi, and Mritunjay Kumar Singh. "Axial Groundwater Contaminant Dispersion Modeling for a Finite Heterogeneous Porous Medium." Water 15, no. 14 (July 24, 2023): 2676. http://dx.doi.org/10.3390/w15142676.

Full text
Abstract:
In this study, a two-dimensional contaminant transport model with time-varying axial input sources subject to non-linear sorption, decay, and production is numerically solved to find the concentration distribution profile in a heterogeneous, finite soil medium. The axial input sources are assigned on the coordinate axes of the soil medium, with background sources varying sinusoidally with space. The groundwater velocities are considered space-dependent in the longitudinal and transversal directions. Various forms of axial input sources are considered to study their transport patterns in the medium. The alternating direction implicit (ADI) and Crank-Nicolson (CN) methods are applied to approximate the two-dimensional governing equation, and the obtained algebraic system of equations in each case is further solved by MATLAB scripts. Both approximate solutions are illustrated graphically for various hydrological input data. The influence of various hydrogeological input parameters, such as the medium’s porosity, density, sorption conditions, dispersion coefficients, etc., on the contaminant distribution is analyzed. Further, the influence of constant and varying velocity parameters on groundwater contaminant transport is studied. The stability of the proposed model is tested using the Peclet and Courant numbers. Substantial similarity is observed when the approximate solution obtained using the CN method is compared with the finite element method in a special case. The proposed approximate solution is compared with the existing numerical solutions, and an overall agreement of 98–99% is observed between them. Finally, the stability analysis reveals that the model is stable and robust.
APA, Harvard, Vancouver, ISO, and other styles
18

Rambourg, Dimitri, Raphaël Di Chiara, and Philippe Ackerer. "Three-dimensional hydrogeological parametrization using sparse piezometric data." Hydrology and Earth System Sciences 26, no. 23 (December 8, 2022): 6147–62. http://dx.doi.org/10.5194/hess-26-6147-2022.

Full text
Abstract:
Abstract. When modelling contamination transport in the subsurface and aquifers, it is crucial to assess the heterogeneities of the porous medium, including the vertical distribution of the aquifer parameter. This issue is generally addressed thanks to geophysical investigations. As an alternative, a method is proposed using estimated hydraulic parameters from a 2D calibrated flow model (solely reliant on piezometric series) as parametrization constraints for a 3D hydrogeological model. The methodology is tested via a synthetic model, ensuring full knowledge and control of its structure. The synthetic aquifer is composed of five lithofacies, distributed according to a sedimentary pattern, and functions in an unconfined regime. The level of heterogeneity for hydraulic conductivity spans 3 orders of magnitude. It provides the piezometric chronicles used to inverse 2D flow parameter fields and the lithological logs used to interpolate the 3D lithological model. Finally, the parameters of each facies (hydraulic conductivity and porosity) are obtained through an optimization loop, which minimizes the difference between the 2D calibrated transmissivity and the transmissivity computed with the estimated 3D facies parameters. The method estimates values close to the known parameters, even with sparse piezometric and lithological data sampling. The maximal discrepancy is 45 % of the known value for the hydraulic conductivity and 6 % for the porosity (mean error 26 % and 3 %, respectively). Although the methodology does not prevent interpolation errors, it succeeds in reconstructing flow and transport dynamics close to the control data. Due to the inherent limitations of the 2D inversion approach, the method only applies to the saturated zone at this point.
APA, Harvard, Vancouver, ISO, and other styles
19

Ma, Hai Yi, Shu Ping Yi, Guo Cheng Ren, and Xue Ling Hu. "Analysis of Uncertainties Affecting Numerical Transport Models for a Potential Radioactive Waste Disposal Site." Advanced Materials Research 955-959 (June 2014): 1607–14. http://dx.doi.org/10.4028/www.scientific.net/amr.955-959.1607.

Full text
Abstract:
Numerical models have been commonly used to study solute transport behaviours both in laboratory-and field-scale cases. However, numerical interpretation and predictions of solute transport are complicated by various uncertainties and therefore can be misleading and lead to incorrect understanding of solute transport behaviours in hydrogeological systems. Such uncertainties have been discussed with a case study of radionuclides transport at a potential site for disposal of Low-and Intermediate-Level radioactive Wastes (LILW) in southern China. Firstly, pre-modelling assumptions cause uncertainties for model performance and have a significant influence on the model output. Therefore, such assumptions and related factors should be thoroughly considered and minimized in laboratory experiments or investigated in the field. Secondly, difference in the calculated plumes caused by uncertainties in the development of conceptual models suggests that the hydrogeological conceptual model should be developed based on intrinsic understanding of the transport problems and relevant data collection. Thirdly, relative sensitivity (RS) has been calculated to analyse the parameter uncertainties. Results indicate that the uncertainties are tracer-, parameter-and time-dependent. Therefore, model uncertainties arising from parameters should be considered for each specific parameter with the specific period. Finally, prediction scenarios are associated with uncertainties in the model prediction stage. Results suggest that the uncertainties in scenarios of future transport conditions should be recognized prior to model prediction. This study illustrates some of the uncertainties that might affect numerical transport models and therefore will be a useful reference for application of solute transport models to assessment of contamination risks from a LILW disposal site.
APA, Harvard, Vancouver, ISO, and other styles
20

Zhou, Jiang, Bing Song, Lei Yu, Wenyi Xie, Xiaohui Lu, Dengdeng Jiang, Lingya Kong, Shaopo Deng, and Min Song. "Numerical Research on Migration Law of Typical Chlorinated Organic Matter in Shallow Groundwater of Yangtze Delta Region." Water 15, no. 7 (April 3, 2023): 1381. http://dx.doi.org/10.3390/w15071381.

Full text
Abstract:
With the reform of China’s urbanization increasing in popularity, the security issues posed by urban groundwater, especially groundwater in industrial areas, have attracted scholars’ attention. This research aimed to predict and quantify the migration process of contaminants in a microconfined aquifer by conducting a groundwater contamination investigation in an abandoned chemical plant in the Jiangsu Province of China. First, data such as regional hydrogeological parameters and types of contaminants were obtained via hydrogeological drilling, groundwater well monitoring, pumping tests, and laboratory permeability tests, which helped identify the most serious pollution factor: chloroform. Then, a groundwater flow model was built using the Groundwater Modeling System (GMS) and verified using the general-purpose parameter estimation (PEST) package. In addition, based on the three-dimensional multi-species model for transport (MT3DMS) in GMS, a transport model was established. The results illustrate that the plume range of chloroform diffuses with water flow, but, because of its slow diffusion rate and inability to degrade naturally, the concentration of the contaminant has remained several times higher than the safety standard for a long time. The contaminant spread vertically to the soil layer above the microconfined aquifer under pressure, resulting in direct pollution. In addition, the contaminant in the microconfined aquifer is anticipated to migrate down to the clay layer and become enriched. However, the first confined aquifer has not been seriously polluted in the past 20 years. Finally, a sensitivity analysis of the parameters shows that groundwater contamination in the Yangtze delta region is greatly affected by precipitation recharge and hydraulic conductivity.
APA, Harvard, Vancouver, ISO, and other styles
21

Tronicke, Jens, Peter Dietrich, Uwe Wahlig, and Erwin Appel. "Integrating surface georadar and crosshole radar tomography: A validation experiment in braided stream deposits." GEOPHYSICS 67, no. 5 (September 2002): 1516–23. http://dx.doi.org/10.1190/1.1512747.

Full text
Abstract:
We have used a combination of surface ground‐penetrating radar (GPR) profiling, crosshole radar tomography, and natural gamma‐ray logging to characterize a gravelly braided stream deposit. In a gravel pit, we conducted a survey using 300‐MHz surface GPR, 250‐MHz crosshole radar, and densely sampled gamma‐ray logging at single‐borehole locations. After excavation, we validated the geophysical results by comparison with the sedimentological and hydrogeological information obtained from the corresponding outcrop wall. We found the visual lithofacies boundaries agreed very well with the images provided by applied geophysical techniques. Our results illustrate how GPR reflector images are improved using tomographic velocity information. In addition, the structural interpretation of tomographic velocity fields is guided by the GPR reflector images in combination with natural gamma‐ray logging results. Groundwater flow and transport modeling was also performed on different subsurface models. The hydrogeological response of parameter distributions derived from a digitized outcrop image are compared with the response of a parameter field derived from the combined geophysical data and with the response of a simple block interpolation between the boreholes. Comparison of cumulative particle arrival times (breakthrough curves) indicates that the characterization of an appropriate real aquifer would benefit from incorporating high‐resolution geophysical data into the analysis.
APA, Harvard, Vancouver, ISO, and other styles
22

Razafindratsima, Stephen, Olivier Péron, Anne Piscitelli, Claire Gégout, Vincent Schneider, Florent Barbecot, Eric Giffaut, Jean-Charles Robinet, Pierre Le Cointe, and Gilles Montavon. "Transport properties of iodide in a sandy aquifer: Hydrogeological modelling and field tracer tests." Journal of Hydrology 520 (January 2015): 61–68. http://dx.doi.org/10.1016/j.jhydrol.2014.11.021.

Full text
APA, Harvard, Vancouver, ISO, and other styles
23

Olariu, Andra, and Marin Palcu. "The origin of ammonium in carbonated mineral waters and its underground transport to one production well in Middle Ciuc Depression from Eastern Carpathians." SIMI 2019, SIMI 2019 (September 20, 2019): 259–78. http://dx.doi.org/10.21698/simi.2019.fp34.

Full text
Abstract:
In many cases in Romania, the mineral waters (in the Neogene Volcanic area of the Eastern Carpathians), especially the carbonate waters, have ammonium in concentration over 0.5 mg/l. The main issue regarding the presence of ammonium is identifying if the concentration is due to the anthropogenic pollution or it is of endogenic origin. The geological, hydrogeological and hydrochemical data analysis resulted in a conceptual model of the aquifer’s spatial position, groundwater movement and mineralization, and ammonium occurrence. The geological and tectonic aspects, aquifer’s recharging, groundwater flow direction, absence of surface pollution sources and correlation of hydrochemical data, all indicate the underground origin of ammonium. The aquifer is generated in pliocene - quaternary granular deposits. In the basement of these granular deposits, in the fracture areas, the groundwater is mixed with carbon dioxide and ammonium emissions, produced in the volcanic chambers. The surface data correlation and the hydrochemical data analysis resulted in the confirmation of the deep ammonium origin. After groundwater flow modeling and ammonium transport simulation, the ammonium plume size and preferential transport directions have been finally elucidated.
APA, Harvard, Vancouver, ISO, and other styles
24

Vergnes, Jean-Pierre, Nicolas Roux, Florence Habets, Philippe Ackerer, Nadia Amraoui, François Besson, Yvan Caballero, et al. "The AquiFR hydrometeorological modelling platform as a tool for improving groundwater resource monitoring over France: evaluation over a 60-year period." Hydrology and Earth System Sciences 24, no. 2 (February 13, 2020): 633–54. http://dx.doi.org/10.5194/hess-24-633-2020.

Full text
Abstract:
Abstract. The new AquiFR hydrometeorological modelling platform was developed to provide short-to-long-term forecasts for groundwater resource management in France. This study aims to describe and assess this new tool over a long period of 60 years. This platform gathers in a single numerical tool several hydrogeological models covering much of the French metropolitan area. A total of 11 aquifer systems are simulated through spatially distributed models using either the MARTHE (Modélisation d'Aquifères avec un maillage Rectangulaire, Transport et HydrodynamiquE; Modelling Aquifers with Rectangular cells, Transport and Hydrodynamics) groundwater modelling software programme or the EauDyssée hydrogeological platform. A total of 23 karstic systems are simulated by a lumped reservoir approach using the EROS (Ensemble de Rivières Organisés en Sous-bassins; set of rivers organized in sub-basins) software programme. AquiFR computes the groundwater level, the groundwater–surface-water exchanges and the river flows. A simulation covering a 60-year period from 1958 to 2018 is achieved in order to evaluate the performance of this platform. The 8 km resolution SAFRAN (Système d'Analyse Fournissant des Renseignements Adaptés à la Nivologie) meteorological analysis provides the atmospheric variables needed by the SURFEX (SURFace EXternalisée) land surface model in order to compute surface runoff and groundwater recharge used by the hydrogeological models. The assessment is based on more than 600 piezometers and more than 300 gauging stations corresponding to simulated rivers and outlets of karstic systems. For the simulated piezometric heads, 42 % and 60 % of the absolute biases are lower than 2 and 4 m respectively. The standardized piezometric level index (SPLI) was computed to assess the ability of AquiFR to identify extreme events such as groundwater floods or droughts in the long-term simulation over a set of piezometers used for groundwater resource management. A total of 56 % of the Nash–Sutcliffe efficiency (NSE; Ef) coefficient calculations between the observed and simulated SPLI time series are greater than 0.5. The quality of the results makes it possible to consider using the platform for real-time monitoring and seasonal forecasts of groundwater resources as well as for climate change impact assessments.
APA, Harvard, Vancouver, ISO, and other styles
25

Kahnt, René, Heinz Konietzky, Thomas Nagel, Olaf Kolditz, Andreas Jockel, Christian B. Silbermann, Friederike Tiedke, et al. "AREHS: effects of changing boundary conditions on the development of hydrogeological systems: numerical long-term modelling considering thermal–hydraulic–mechanical(–chemical) coupled effects." Safety of Nuclear Waste Disposal 1 (November 10, 2021): 175–77. http://dx.doi.org/10.5194/sand-1-175-2021.

Full text
Abstract:
Abstract. Within the framework of the “Gesetz zur Suche und Auswahl eines Standortes für ein Endlager für hochradioaktive Abfälle” (Repository Site Selection Act – StandAG), the geoscientific and planning requirements and criteria for the site selection for a repository for high-active nuclear waste are specified. This includes, among others, the modelling of hydrogeological scenarios such as how future cold and warm periods and associated glaciation events can change the (petro-)physical properties specified in the StandAG as well as the natural hydrogeological properties of the overall system through, for example, reactivation of faults or changes in hydraulic gradients and consequently flow directions. The main objective of the AREHS (Effects of Changing Boundary Conditions on the Development of Hydrogeological Systems) project, funded by BASE (Federal Office for the Safety of Nuclear Waste Management; FKZ 4719F10402), is to model the effects of changing external boundary conditions on the hydrogeologically relevant parameters and effects (e.g. hydraulic permeability, porosity, migration pathways, fluid availability, hydraulic gradients) of a generic geological repository in Germany in all three potential host rocks (clay, salt and crystalline rocks) and its surrounding hydrogeological setting (Table 1). Special attention is paid to the cyclic mechanical loading and unloading due to glaciation events and the resulting stress changes (M), as well as induced temperature effects (T) due to permafrost and warm periods. As such processes can cause changes in the coupled far-field regime with groundwater flow and groundwater supply (H), as well as fluid transport due to thermal (T) and chemical (C) gradients, and reactivate faults/fractures (M) and thus create new/additional pathways, they are particularly relevant to the integrity of a repository over a period of 1 million years and must be properly captured with coupled THM(C) modelling. Before a model is set up for the different host rocks, a detailed assessment of relevant processes has been conducted based on NEA-2019 FEP catalogue (NEA, 2019) for high-level waste repositories. The modelling is performed using generic 3D models of typical host rock formations satisfying the StandAG criteria. Although the models for salt and clay rock have been adapted from generic models from recent research projects, for crystalline rock a new generic model had to be developed (Fig. 1) considering discontinuities of different scales that have to be incorporated into the THM(C) models explicitly as DFN (Discrete Fracture Network) networks. This is done by coupling two numerical codes: DFN-lab and 3DEC. A central phase in the overall modelling process is the benchmarking of the models with data from existing models and with field-scale studies. This is done separately for all three host rocks. In addition to extending the modelling capacities for glaciation processes and verifying by corresponding benchmarking tests (analytical solutions and literature comparisons), automated workflows have been developed to generate OpenGeoSys models from GOCAD structure models. Script-based automated workflows improve software quality for site investigation, especially in a sense of modularization as well as reproducibility. The generic workflow concept is currently being tested for the literature-based benchmarks and will, therefore, support a persistent and sustainable benchmarking procedure in the future.
APA, Harvard, Vancouver, ISO, and other styles
26

Manek, E. G., D. P. E. Putra, and H. Hendrayana. "Mass transport modelling of total organic carbon in groundwater to determine the location of petroleum fuel pollutant sources in the area of Jlagran, Yogyakarta City, Indonesia." IOP Conference Series: Earth and Environmental Science 851, no. 1 (October 1, 2021): 012024. http://dx.doi.org/10.1088/1755-1315/851/1/012024.

Full text
Abstract:
Abstract Hydrocarbon pollution in the Jlagran area’s groundwater, Yogyakarta City, has been going on for more than 20 years. So far, the pollution source has been inferred from a leak in the diesel fuel storage tank from near Train Station. This study aims to prove the claim that the source of hydrocarbon pollutants comes from the location of the fuel storage tank or not. This research was conducted by collecting data on hydrogeological aspects and total organic carbon (TOC) concentration in groundwater, followed by modeling flow and mass transport using Visual Modlfow MT3DMS. The modeling results show that the contamination plume distribution in groundwater at the recent time cannot be caused by only one point source, namely the fuel oil storage tank’s location, but also may come from the train maintenance area. It is estimated on this area that the disposal of train maintenance waste of hydrocarbon as a result of poor practices for at least two decades has been developing a residual hydrocarbon zone in the unsaturated zone, and now potentially seeped into the aquifer and also contribute as a source of hydrocarbon pollutant to groundwater.
APA, Harvard, Vancouver, ISO, and other styles
27

Bugai, D., A. Skalskyy, S. Dzhepo, Yu Kubko, V. Kashparov, N. Van Meir, D. Stammose, C. Simonucci, and A. Martin-Garin. "Radionuclide migration at experimental polygon at Red Forest waste site in Chernobyl zone. Part 2: Hydrogeological characterization and groundwater transport modeling." Applied Geochemistry 27, no. 7 (July 2012): 1359–74. http://dx.doi.org/10.1016/j.apgeochem.2011.09.028.

Full text
APA, Harvard, Vancouver, ISO, and other styles
28

Akmatov, D. Zh, A. A. Tikhonov, and D. Z. Kappushev. "Numerical modeling of geomechanical processes in construction of the Moscow Metro running tunnels." Mining Industry Journal (Gornay Promishlennost), no. 1/2022 (March 15, 2022): 133–37. http://dx.doi.org/10.30686/1609-9192-2022-1-133-137.

Full text
Abstract:
The largest megalopolis and the main business center of the country, the city of Moscow, is actively expanding from year to year. In this context, the Russian capital is faced with the challenge of developing and expanding its transport infrastructure. According to the 2021 construction plan of the Moscow Metro the total length of the lines will exceed 450 km, and the Big Circle Line will become one of the longest in the world. During the construction of new metro stations specialists face difficult engineering, geological and hydrogeological conditions. Reducing the risks and preventing accidents during underground construction is relying on accounting of all the levels of the excavation and construction works. The article presents a comprehensive analysis of the factors that affect the choice and justification of underground construction technologies. The paper presents the objectives of geomechanical monitoring and measures for geomechanical safety of excavations. Numerical modeling of geomechanical processes during the construction of the running tunnels was made using the Map3D Software. The simulation considered a tunnel of circular cross-section passing through a non-uniform rock mass. The diameter of the cross-section was accepted to be 6 m with the depth of the driving tunnel varying from 15 to 35 m.
APA, Harvard, Vancouver, ISO, and other styles
29

Świdziński, Waldemar. "Modeling groundwater flow and salinity evolution near TSF Żelazny Most. Part I – groundwater flow." E3S Web of Conferences 54 (2018): 00036. http://dx.doi.org/10.1051/e3sconf/20185400036.

Full text
Abstract:
Tailings which are by-product of the extraction of various metals (copper, gold, silver, molybdenum, etc.) are often stored in so called Tailings Storage Facilities (TSF), where they are deposited as a soil-water mixture by spigotting. In many cases the water discharged together with tailings to the TSF is rich in salts and other chemical compounds imposing negative pressure to the groundwater environment. Even in the case of total or partial lining of such facilities and well-developed drainage systems to control leaching, some portion of contaminated water often seeps either through the surrounding dams or the bed into adjacent groundwater bodies. Numerical models can be very helpful tools to assess the extent of the contamination and particularly to predict its potential development in the future. This paper and the companion one describe such a numerical model developed for Żelazny Most Tailings Storage Facility (south-west Poland), one of the world’s largest tailings sites. In the first part general information about the facility is provided and a 3D hydrogeological numerical model of the structure is described. Groundwater flow pattern near the facility obtained from numerical simulations is confronted with the measurements from a comprehensively developed monitoring system. Part II will be focused on the modelling of chloride transport in groundwater.
APA, Harvard, Vancouver, ISO, and other styles
30

Behroozmand, Ahmad Ali, Pietro Teatini, Jesper Bjergsted Pedersen, Esben Auken, Omar Tosatto, and Anders Vest Christiansen. "Anthropogenic wetlands due to over-irrigation of desert areas: a challenging hydrogeological investigation with extensive geophysical input from TEM and MRS measurements." Hydrology and Earth System Sciences 21, no. 3 (March 10, 2017): 1527–45. http://dx.doi.org/10.5194/hess-21-1527-2017.

Full text
Abstract:
Abstract. During the last century, many large irrigation projects were carried out in arid lands worldwide. Despite a tremendous increase in food production, a common problem when characterizing these zones is land degradation in the form of waterlogging. A clear example of this phenomenon is in the Nubariya depression in the Western Desert of Egypt. Following the reclamation of desert lands for agricultural production, an artificial brackish and contaminated pond started to develop in the late 1990s, which at present extends for about 2.5 km2. The available data provide evidence of a simultaneous general deterioration of the groundwater system. An extensive hydrogeophysical investigation was carried out in this challenging environment using magnetic resonance sounding (MRS) and ground-based time-domain electromagnetic (TEM) techniques with the following main objectives: (1) understanding the hydrological evolution of the area; (2) characterizing the hydrogeological setting; and (3) developing scenarios for artificial aquifer remediation and recharge. The integrated interpretation of the geophysical surveys provided a hydrogeological picture of the upper 100 m sedimentary setting in terms of both lithological distribution and groundwater quality. The information is then used to set up (1) a regional groundwater flow and (2) a local density-dependent flow and transport numerical model to reproduce the evolution of the aquifer system and develop a few scenarios for artificial aquifer recharge using the treated water provided by a nearby wastewater treatment plant. The research outcomes point to the hydrological challenges that emerge for the effective management of water resources in reclaimed desert areas, and they highlight the effectiveness of using advanced geophysical and modeling methodologies.
APA, Harvard, Vancouver, ISO, and other styles
31

Demichele, Francesco, Fabian Micallef, Ivan Portoghese, Julian Alexander Mamo, Manuel Sapiano, Michael Schembri, and Christoph Schüth. "Determining Aquifer Hydrogeological Parameters in Coastal Aquifers from Tidal Attenuation Analysis, Case Study: The Malta Mean Sea Level Aquifer System." Water 15, no. 1 (January 1, 2023): 177. http://dx.doi.org/10.3390/w15010177.

Full text
Abstract:
The coastal and carbonate Mean Sea Level Aquifer (MSLA) of Malta is characterised by high anisotropy and heterogeneity, which together make evaluating the aquifer system parameters a challenging task. In this paper, we present an approach for the determination of the hydrogeological parameters of this coastal aquifer based on tidal-induced groundwater fluctuations that can be applied in other similar contexts. This work presents an analysis of data undertaken on monitoring boreholes located in the Malta MSLA exhibiting tidal-induced groundwater fluctuations. This allowed us to determine the values of three main hydrogeological parameters: hydraulic diffusivity, transmissivity and hydraulic conductivity. These will subsequently be used as an input for groundwater flow and reactive transport modelling purposes. In this study, a methodology based on the fast Fourier transform (FFT) is proposed to improve the applicability of the Jacob–Ferris method to the observed groundwater level and sea level fluctuations. The FFT reproduced signals allowed us to isolate the component induced by sea tides, thus eliminating short- and long-term variations of the water table induced by other disruptive factors. Results showed high variability of hydrogeological parameters within a short distance, reflecting the high anisotropy and heterogeneity of the aquifer system. The transmissivity values derived from the Jacob–Ferris method are complemented with results derived from the pumping tests with the aim of estimating the spatial distribution of the aquifer transmissivity for the study area. The spatial variability of transmissivity values is analysed by means of geostatistics tools for estimating uncertainty, correlation and variation in space through the use of semi-variograms.
APA, Harvard, Vancouver, ISO, and other styles
32

Karmakar, Shyamal, Alexandru Tatomir, Sandra Oehlmann, Markus Giese, and Martin Sauter. "Numerical Benchmark Studies on Flow and Solute Transport in Geological Reservoirs." Water 14, no. 8 (April 17, 2022): 1310. http://dx.doi.org/10.3390/w14081310.

Full text
Abstract:
Predicting and characterising groundwater flow and solute transport in engineering and hydrogeological applications, such as dimensioning tracer experiments, rely primarily on numerical modelling techniques. During software selection for numerical modelling, the accuracy of the results, financial costs of the simulation software, and computational resources should be considered. This study evaluates numerical modelling approaches and outlines the advantages and disadvantages of several simulators in terms of predictability, temporal control, and computational efficiency conducted in a single user and single computational resource set-up. A set of well-established flow and transport modelling simulators, such as MODFLOW/MT3DMS, FEFLOW, COMSOL Multiphysics, and DuMuX were tested and compared. These numerical simulators are based on three numerical discretisation schemes, i.e., finite difference (FD), finite element (FE), and finite volume (FV). The influence of dispersivity, potentially an artefact of numerical modelling (numerical dispersion), was investigated in parametric studies, and results are compared with analytical solutions. At the same time, relative errors were assessed for a complex field scale example. This comparative study reveals that the FE-based simulators COMSOL and FEFLOW show higher accuracy for a specific range of dispersivities under forced gradient conditions than DuMuX and MODFLOW/MT3DMS. FEFLOW performs better than COMSOL in regard to computational time both in single-core and multi-core computing. Overall computational time is lowest for the FD-based simulator MODFLOW/MT3DMS while the number of mesh elements is low (here < 12,800 elements). However, for finer discretisation, FE software FEFLOW performs faster.
APA, Harvard, Vancouver, ISO, and other styles
33

Casasso, Alessandro, Natalia Ferrantello, Simone Pescarmona, Carlo Bianco, and Rajandrea Sethi. "Can Borehole Heat Exchangers Trigger Cross-Contamination between Aquifers?" Water 12, no. 4 (April 20, 2020): 1174. http://dx.doi.org/10.3390/w12041174.

Full text
Abstract:
Borehole heat exchangers (BHEs) commonly reach depths of several tens of meters and cross different aquifers. Concerns have been raised about the possibility of boreholes to act as preferential pathways for contaminant transport among aquifers (cross-contamination). This article employs numerical modelling of contaminant transport in the subsurface to address these concerns. A common hydrogeological setup is simulated, composed of three layers: A shallow contaminated and a deep uncontaminated aquifer separated by an aquitard, all crossed by a permeable borehole. The hydraulic conductivity of the borehole and, to a lesser extent, the vertical hydraulic gradient between the aquifers are the key factors of cross-contamination. Results of the numerical simulations highlight that, despite the severe conditions hypothesized in our modelling study, the cross-contamination due to the borehole is negligible when filled with a slightly permeable material such as a geothermal grout properly mixed and injected. A good agreement was found with analytical formulas used for estimating the flow rate leaking through the borehole and for studying the propagation of leaked contaminant into the deep aquifer.
APA, Harvard, Vancouver, ISO, and other styles
34

Zhu, Henghua, Jianwei Zhou, Chao Jia, Sheng Yang, Jing Wu, Lizhi Yang, Zhengrun Wei, Hongwei Liu, and Zhizheng Liu. "Control Effects of Hydraulic Interception Wells on Groundwater Pollutant Transport in the Dawu Water Source Area." Water 11, no. 8 (August 11, 2019): 1663. http://dx.doi.org/10.3390/w11081663.

Full text
Abstract:
Based on the comprehensive analysis of hydrogeological data of the Dawu water source in Zibo city, the Modflow module in Groundwater Modeling System is used to carry out three-dimensional geological modeling of the Dawu water source, and the flow field model and solute transport model of the Dawu water source are established. Aiming at the problem of groundwater pollution in the key polluted area of the Hougao region—the Dawu water source—the pollutant transport model is established to explore the process of pollution transport. There are many types of groundwater pollutants in the Hougao area. Among them, ammonia nitrogen, chloride, petroleum, and benzene exceed the standard most seriously. In order to facilitate the research, we selected typical pollutants for in-depth study. The ammonia nitrogen is used as the control index of domestic and industrial waste water in the policy documents of pollution emission. It can show the specific situation of industrial waste water and domestic waste water pollution changing with time. Thus, the ammonia nitrogen with a higher exceeding standard is selected as the pollution factor in this simulation. Pollutant transport under the conditions of strong pumping and stop pumping is simulated. It is found that the pollutant is effectively controlled due to the pumping and discharging effects under the action of strong pumping, from 4 to 5 times exceeding the standard to slightly exceeding the standard. However, there is still a trend of migration to the eastern water supply area. After the pumping is stopped, the pollutant quickly migrates to the Xixia centralized water supply area, causing serious pollution to the water supply area. Finally, four other hydraulic interception wells are set up in the 500 m east of Hougao’s four wells to further control the pollutant transport. When hydraulic interception wells and strong pumping wells are used together, the scope of ammonia nitrogen pollution is basically controlled near the interception wells, and it does not continue to spread to the eastern water supply area. The maximum monitoring value of pollution is 0.11 mg/L, which is controlled within the standard limit of three types of groundwater, and the pollutant control effect is the best, providing certain reference for similar pollution control work.
APA, Harvard, Vancouver, ISO, and other styles
35

Mirlas, Vladimir, Vitaly Kulagin, Aida Ismagulova, and Yaakov Anker. "MODFLOW and HYDRUS Modeling of Groundwater Supply Prospect Assessment for Distant Pastures in the Aksu River Middle Reaches." Sustainability 14, no. 24 (December 14, 2022): 16783. http://dx.doi.org/10.3390/su142416783.

Full text
Abstract:
As in many regions across the world, southeastern Kazakhstan is subjected to ongoing water-resource depletion. The livestock sector is already a major natural water resource consumer, with groundwater use becoming its water supply strategy. Remote pasture infrastructure development requires new water resources to allow pasture area circulation. The distant pastures in the middle reach of the Aksu River consist of three pastures, with a total area of 32,450 ha and a permissible number of 3245 livestock heads. The HYDRUS-1D water transport model and MODFLOW groundwater-flow model simulated complex water infrastructure prospect hydrogeological scenarios to allow the consumption of 302.4 m3 per day for livestock keeping on pasturelands. During pumping for livestock watering, projected production well drawdowns were quantitatively evaluated. The findings show that the projected pumping flow rate equals 288 m3/day during the water consumption season and 95 m3/day outside the water consumption season. While the production wells on pastures No. 2 and No. 3 can be considered reliable, on pasture No. 1, an additional production well is needed. To maintain the production wells’ drawdowns to less than 6 m, a projected pumping flow rate reduction to 216 m3/day and 70 m3/day, respectively, is required.
APA, Harvard, Vancouver, ISO, and other styles
36

Tatomir, Alexandru, Dejian Zhou, Huhao Gao, Alexandru-Nicolae Dimache, Iulian Iancu, and Martin Sauter. "Modelling of kinetic interface sensitive tracers reactive transport in 2D two-phase flow heterogeneous porous media." E3S Web of Conferences 85 (2019): 07003. http://dx.doi.org/10.1051/e3sconf/20198507003.

Full text
Abstract:
Fluid-fluid interfacial area plays an important role for mass- and energy-transfer processes across the interface which is relevant in several hydrogeological and engineering applications, e.g. enhanced oil-gas recovery, CO2 storage in geological formations, unconventional geothermal systems, contaminant removal, etc. Kinetic interface sensitive tracers were designed to determine the size of the interface between two fluids by undergoing hydrolysis at the fluid-fluid interface. This study investigates by means of numerical modelling the influence of heterogeneity on the KIS tracer breakthrough curves in six idealized scenarios (S1-S6). It is an extension of the previous work conducted in “one-dimensional” column experiments by Tatomir et al. (2018) [1]. The changes in interfacial area are created by inclusion of heterogeneities at the Darcy-scale. The results show that KIS tracers can be used in two-dimensional experimental setup and can provide information about the size and dynamic evolution of interfacial area. Therefore, this is a first step for the dimensioning of an experimental flume.
APA, Harvard, Vancouver, ISO, and other styles
37

Zimmermann, J., C. Dierkes, P. Göbel, C. Klinger, H. Stubbe, and W. G. Coldewey. "Metal concentrations in soil and seepage water due to infiltration of roof runoff by long term numerical modelling." Water Science and Technology 51, no. 2 (January 1, 2005): 11–19. http://dx.doi.org/10.2166/wst.2005.0027.

Full text
Abstract:
The qualitative effects of stormwater infiltration on soil and seepage water are investigated with long term numerical modelling. The retention behaviour of different soils and materials used in infiltration devices is determined with batch and column tests. Results of the laboratory tests are adsorption isotherms which represent input data for numerical transport modelling. The long term simulations are performed with combinations of different solutions (types of roof runoff) and infiltration devices (swale and trench) under different hydrogeological conditions. The presented results contain the infiltration of low polluted roof runoff, runoff from a roof with zinc sheets and from a roof with copper sheets concerning the heavy metals zinc, copper and lead. The increase of concentrations in the infiltration body is high. For the infiltrated water, the results show a migration to groundwater only for the low adsorbing soil.
APA, Harvard, Vancouver, ISO, and other styles
38

Srisuk, K., V. Sribooniue, C. Buaphan, L. Archvichai, W. Youngme, P. Satarak, and S. Jaruchaikul. "Numerical modeling of saline water transport in the lower Nam Kam Basin, Amphoe That Phanom, Changwat Nakhon Phanom, Thailand." Water Science and Technology 44, no. 7 (October 1, 2001): 157. http://dx.doi.org/10.2166/wst.2001.0414.

Full text
Abstract:
The objective of the project is to establish a conceptual groundwater model over the lower Nam Kam Basin in order to apply a numerical technique for the prediction of the impact of saline water transport due to the proposed weir across the Nam Kam River. Hydrogeological investigations including mapping, drilling, piezometer installations and monitoring were systematically conducted during 1997 to 1998. Brackish groundwater is saturated under the area with a depth of 30-60 m. Groundwater regionally flows from the south (the Phu Phan Range) to the north and discharges to the Nam Kam River. Another direction is from the northern region to the southern region, discharging to the central region. A two-dimensional model was constructed along the principal gradient in the NW-SE direction. There are several local recharge and discharge areas across the Nam Kam floodplain. A local groundwater flow is active within the depth of 2 m to 30 m below the ground surface within the sand and gravel unit. Simulations were calibrated with hydraulic heads and salinity of groundwater in the piezometers. It is found that the recharge and evapotranspiration rates are 1% to 40% of the rainfall and 10% to 15% of a pan evaporation, respectively. The ranges of horizontal hydraulic conductivity to vertical hydraulic conductivity are 0.1 to 0.01. The possible longitudinal dispersivity values of the hydrostratigraphic units are 20 m to 500 m, but the transverse dispersivity is less than the longitude by one order of magnitude. The comparison of calculated heads and measured heads give a root mean square error of less than 1 m. The different salinity concentrations are still in a range of 2000 - 5000 mg/l. Ten year simulation of saline water transport indicates that the reservoir ponding with water level at +140.5 m above mean sea level may divert groundwater flow and discharging to the northern boundary of the reservoir at Ban Don Kao.
APA, Harvard, Vancouver, ISO, and other styles
39

Abbate, Andrea, Leonardo Mancusi, Francesco Apadula, Antonella Frigerio, Monica Papini, and Laura Longoni. "CRHyME (Climatic Rainfall Hydrogeological Modelling Experiment): a new model for geo-hydrological hazard assessment at the basin scale." Natural Hazards and Earth System Sciences 24, no. 2 (February 14, 2024): 501–37. http://dx.doi.org/10.5194/nhess-24-501-2024.

Full text
Abstract:
Abstract. This work presents the new model called CRHyME (Climatic Rainfall Hydrogeological Modelling Experiment), a tool for geo-hydrological hazard evaluation. CRHyME is a physically based and spatially distributed model written in the Python language that represents an extension of the classic hydrological models working at the basin scale. CRHyME's main focus consists of simulating rainfall-induced geo-hydrological instabilities such as shallow landslides, debris flows, catchment erosion and sediment transport into a river. These phenomena are conventionally decoupled from a hydrological routine, while in CRHyME they are simultaneously and quantitatively evaluated within the same code through a multi-hazard approach. CRHyME is applied within some case studies across northern Italy. Among these, the Caldone catchment, a well-monitored basin of 27 km2 located near the city of Lecco (Lombardy), was considered for the calibration of solid-transport routine testing, as well as the spatial-scale dependence related to digital terrain resolution. CRHyME was applied across larger basins of the Valtellina (Alps) and Emilia (Apennines) areas (∼2600 km2) which have experienced severe geo-hydrological episodes triggered by heavy precipitation in the recent past. CRHyME's validation has been assessed through NSE (Nash–Sutcliffe efficiency) and RMSE (root mean square error) hydrological-error metrics, while for landslides the ROC (receiver operating characteristic) methodology was applied. CRHyME has been able to reconstruct the river discharge at the reference hydrometric stations located at the outlets of the basins to estimate the sediment yield at some hydropower reservoirs chosen as a reference and to individuate the location and the triggering conditions of shallow landslides and debris flows. The good performance of CRHyME was reached, assuring the stability of the code and a rather fast computation and maintaining the numerical conservativity of water and sediment balances. CRHyME has shown itself to be a suitable tool for the quantification of the geo-hydrological process and thus useful for civil-protection multi-hazard assessment.
APA, Harvard, Vancouver, ISO, and other styles
40

Valstar, J. R., and N. Goorden. "Far-field transport modelling for a repository in the Boom Clay in the Netherlands." Netherlands Journal of Geosciences 95, no. 3 (May 25, 2016): 337–47. http://dx.doi.org/10.1017/njg.2016.13.

Full text
Abstract:
AbstractA groundwater model was set up to study far-field transport for the potential of a radioactive waste repository the Boom Clay in the Netherlands. The existing national groundwater model, the Netherlands Hydrological Instrument, was extended in the vertical direction to include geological formation up to and beyond the Boom Clay. As the amount of hydrogeological data in the deeper subsurface is limited, simplifications in the model schematisation were necessary. Moreover, nationwide data about the tops and bottoms of many of the deeper geological formations and their members are lacking and required interpolation. Finally, values for hydrogeological parameters, such as porosity and hydraulic conductivity, are also lacking for the deeper formations. These values were estimated using relationships with depth and lithology. Moreover, no quantitative data about heterogeneity within the deeper geological formations or its members were available.In the Dutch research programme on the geological disposal of radioactive waste (OPERA), the post-closure safety of a generic repository is assessed in either Boom Clay or rock salt. Disposal of Dutch radioactive waste is not foreseen in the next decades and a choice of host rock has not been made. In the early, conceptual phase of the radioactive waste disposal process in the Netherlands no potential repository locations were selected and a groundwater flow model for the entire Netherlands was build. As a starting point a geological disposal facility is assumed to be present at a depth of at least 500 m within a Boom Clay formation of 100 m in order to be able to make an assessment of post-closure safety with this geological formation in a disposal concept. With these assumptions, a general idea of potential flow patterns has been obtained and broken down into pathline trajectories. These trajectories were calculated to achieve input for the potential transport of radioactive isotopes (radionuclides) from this waste in the Netherlands after the closure of a disposal facility in Boom Clay.The groundwater flow patterns in the deeper subsurface strongly resemble the larger scale flow patterns in the shallow subsurface, with flow from infiltration areas in the east and the south of the Netherlands towards to seepage areas of the polders in the west and the northern part of the country or towards the river valleys of the Rhine and IJssel. Groundwater flow velocities, however, are much lower in the deeper part of the model and consequently travel times are much larger. The conservative travel times from the pathlines range from a few 1000 years to more than 10,000,000 years depending on the location for the repository. Longer travel times are obtained for locations with a downward groundwater flow in the Boom Clay.Because of the simplifications in the model schematisation and the uncertainty in the model parameters, the present results should only be considered as a first indication. Moreover, the model could not be validated due to a lack of validation data. However, the insight gained with the model may help to design a data collection strategy for dedicated model validation, such as measuring the hydraulic gradient over the Boom Clay to validate downward flow in the Boom Clay to obtain the necessary data for a post-closure safety assessment.
APA, Harvard, Vancouver, ISO, and other styles
41

King, Jude, Tobias Mulder, Gualbert Oude Essink, and Marc F. P. Bierkens. "Joint estimation of groundwater salinity and hydrogeological parameters using variable-density groundwater flow, salt transport modelling and airborne electromagnetic surveys." Advances in Water Resources 160 (February 2022): 104118. http://dx.doi.org/10.1016/j.advwatres.2021.104118.

Full text
APA, Harvard, Vancouver, ISO, and other styles
42

Dimkic, Milan, Srdjan Kovacevic, Milenko Pusic, and Milan Dotlic. "Modeling of sorption and degradation of selected pharmaceuticals: Case study of Belgrade groundwater source." Annales g?ologiques de la Peninsule balkanique, no. 78 (2017): 47–59. http://dx.doi.org/10.2298/gabp1778047d.

Full text
Abstract:
The application of a mathematical model that analyzes the transport of selected pharmaceuticals from the Sava River to a corresponding radial collector well at Belgrade?s groundwater source is assessed. The occurrence of the selected pharmaceuticals in surface water and the corresponding well was monitored from 2009 to 2015. The pharmaceuticals selected for the present study are carbamazepine, trimethoprim, and metamizole metabolites 4-AAA and 4-FAA. Transport is analyzed based on experimental data (sorption isotherms) and a field tracer experiment that includes injection of the selected pharmaceuticals. The analysis shows that sorption of carbamazepine is relatively low and that this pharmaceutical does not degrade under the studied conditions, so it is not possible to accurately determine the degradation half-life. Trimethoprim is detected in the Sava River with an average concentration 8.5 ng/L, but there is no positive detection in well Rb-16. The average concentration of 4-AAA in the surface water is 34 ng/L and of 4-FAA 13 ng/L. The average concentrations of 4-FAAand 4-AAA in the groundwater are in the range from 1 and 1.85 ng/L. The objective of the research is to use an existing hydrogeologic model and apply a transport model to determine the minimum degradation half-life of the investigated pharmaceuticals.
APA, Harvard, Vancouver, ISO, and other styles
43

Steiakakis, Emmanouil, Dionysios Vavadakis, and Ourania Mourkakou. "Groundwater Vulnerability and Delineation of Protection Zones in the Discharge Area of a Karstic Aquifer—Application in Agyia’s Karst System (Crete, Greece)." Water 15, no. 2 (January 5, 2023): 231. http://dx.doi.org/10.3390/w15020231.

Full text
Abstract:
This work represents a contribution to the protection techniques of karst aquifers against groundwater pollution. The paper sets out the methodology being introduced for the protection of the karstic system that gives rise to five (5) major groups of springs and supplies fourteen (14) pumping wells near Agyia Chania (Crete, Greece). Starting from a geological and hydrogeological survey of the area, the work presents a vulnerability assessment of the karstic aquifer based on the application of three index-based methods (EPIK, PRESK and DRISTPI). The protection zones for the discharge area of the aquifer were delineated through an integrated geomorphological approach and groundwater flow modeling. At first, the risk of polluting substances migration from ground surface to groundwater was considered based on the spatial distribution of vulnerability. Following this, the vulnerability was evaluated in the saturated zone, where the attenuation mechanisms of contaminants were reducing due to the raised flow velocity. The groundwater flow and contaminant transport processes was considered using the MODFLOW code. Next, the data from the vulnerability mapping and the groundwater flow simulation were merged into an integrated assessment to delimit the protection zones for the water abstraction points. The vulnerability assessment outlines zones of high vulnerability in the SE part of the area, far away from the discharge zone of the aquifer and the water abstraction points. These zones are associated with an intensive infiltration process via carbonate formations. Protection Zone I was delineated 20 m around the water abstraction points, and it should be excluded from any anthropogenic activity. Protection Zone II coves part of the very high and high vulnerability zones defined by the DRISTPI method (located upwards of the water abstraction points), as well as an area downwards of springs and wells, where the flow path lines which demonstrate the subsurface travelling time of 50 days are projected to the ground surface. Protection Zone III extends outside Zone Ι and Zone ΙΙ, up to the limits of the hydrogeological or hydrological basin, whichever is larger. It includes the entire capture zone (i.e., the surface and underground catchment area) that feeds the water abstraction points. In this manner the protection zones include the entire contributing area to water abstraction points, not just the ground surface recharge zone.
APA, Harvard, Vancouver, ISO, and other styles
44

Chabab, Elena, Michael Kühn, and Thomas Kempka. "Upwelling mechanisms of deep saline waters via Quaternary erosion windows considering varying hydrogeological boundary conditions." Advances in Geosciences 58 (November 14, 2022): 47–54. http://dx.doi.org/10.5194/adgeo-58-47-2022.

Full text
Abstract:
Abstract. Intrusion of deep saline waters into freshwater aquifers does not only endanger the regional drinking water supply, but also rivers and stagnant waters and their fauna are threatened by salinisation. The upwelling of highly mineralised saline waters in large parts of the North German Basin is favoured by the presence of Elsterian glacial erosion windows in the Lower Oligocene Rupelian Clay, the most important hydraulic confining unit in this region. Lower precipitation rates and decreasing groundwater levels as a consequence of global climate change, but also anthropogenic interventions, such as increasing extraction rates or the use of the deep geologic subsurface as a reservoir, decrease the pressure potential in the freshwater column and may possibly accelerate this primarily geogenic salinisation process in the coming years. Density-driven flow and transport modelling was performed in the scope of the present study to investigate the upwelling mechanisms of deep saline waters across Quaternary window sediments in the Rupelian. Simulation results show that the interactions between the groundwater recharge rate and anthropogenic interventions such as extraction rates of drinking water wells or the utilisation of the deep subsurface, have a significant influence on the groundwater pressure potential in the freshwater aquifer and associated saltwater upwelling. In all scenarios, salinisation is most severe in the sediments of the erosion windows. Hydraulically conductive faults also intensify salinisation if located nearside erosion windows or induce a more distributed or localised salinisation in aquifers with drinking water relevance in areas that do not intersect with erosion windows. A decline in groundwater recharge thereby significantly favours upward saltwater migration. The simulation scenarios further show that a decrease in groundwater recharge also results in freshwater salinisation occurring up to 10 years earlier, which underlines the need for waterworks to initiate effective countermeasures quickly and in time.
APA, Harvard, Vancouver, ISO, and other styles
45

Slater, Lee D., and Stewart K. Sandberg. "Resistivity and induced polarization monitoring of salt transport under natural hydraulic gradients." GEOPHYSICS 65, no. 2 (March 2000): 408–20. http://dx.doi.org/10.1190/1.1444735.

Full text
Abstract:
We demonstrate the use of resistivity/induced polarization (IP) monitoring of salt transport under natural hydraulic loads. Electrical monitoring of saline tracer transport during forced injection has been demonstrated previously. Detection of tracer transport under natural hydraulic loading is difficult because neither the hydraulic load nor the tracer resistivity can be controlled. In one study, we identify the electrical response to salt transport in a dynamic beach environment. Resistivity/IP imaging resolved the structure of the saltwater‐freshwater interface and evidence for tide‐induced groundwater transport. Resistivity increases in the near surface and at depth, upbeach of the high‐tide mark, accompanied by tidal transgression. We attribute this to desaturation and decreasing salinity in the near surface and to decreasing salinity at depth, despite tidal transgression. Monitoring of groundwater levels indicates a phase lag between the tide level and groundwater level, supporting the electrical data. IP was insensitive to groundwater salinity variation. In a second study, we identify the electrical response to recharge‐induced salt transport from a road‐salt storage facility. Conductivity and IP models for monitoring lines, located on the basis of an EM31 survey, resolved the subsurface salt distribution. IP modeling resolved the sediment‐bedrock interface. Modeling of monthly conductivity differences revealed conductivity increases and decreases at the locations of salt contamination, which correlate with the recharge pattern. We attribute near‐surface conductivity increases after heavy rainfall to increasing saturation and ion dissolution. Corresponding conductivity decreases at depth are attributed to flushing of the bedrock with freshwater. Essentially, the opposite response was observed during a quiet monitoring period following heavy recharge. Near‐surface IP changes are consistent with this interpretation. Salt transport occurring under natural hydraulic conditions was monitored with resistivity imaging. IP improved characterization of the hydrogeologic framework but was of limited value in monitoring salt transport in these environments.
APA, Harvard, Vancouver, ISO, and other styles
46

Faybishenko, Boris. "A Concept of Fuzzy Dual Permeability of Fractured Porous Media." Water 15, no. 21 (October 27, 2023): 3752. http://dx.doi.org/10.3390/w15213752.

Full text
Abstract:
The interpretation of the results of hydrogeological field observations and the modeling of fractured porous subsurface media is often conducted using dual-porosity and/or dual-permeability concepts. These concepts, however, do not consider the effects of spatial and temporal variations and uncertainties, or fuzziness, in the evaluation of the subsurface flow characteristics of fractured porous media. The goal of the paper is to introduce a concept of fuzzy dual permeability of fractured porous media based on the fuzzy system analysis of the results of ponded infiltration tests in fractured basalt. The author revisited the results of the tests conducted in areas close to the Idaho National Laboratory (INL), Idaho, USA: small-scale (approximately 0.5 m2) ponded tests at the Hell’s Half Acre site, mesoscale (56 m2) ponded tests at the Box Canyon site, and a large-scale infiltration test (31,416 m2) at the Radioactive Waste Management Complex at INL. Methods of fuzzy clustering and fuzzy regression were applied to describe the time-depth waterfront penetration and to characterize the phenomena of rapid flow through a predominantly fractured component and slow flow through a predominantly porous matrix component. The concept of fuzzy dual permeability is presented using a series of fuzzy membership functions of the waterfront propagation with depth and time. To describe the time variation of the flux, a fuzzy Horton’s model is presented. The developed concept can be used for the uncertainty quantification in flow and transport in geologic media.
APA, Harvard, Vancouver, ISO, and other styles
47

Kim, J. W., J. Kim, H. Choi, and F. W. Schwartz. "Modeling the fate and transport of organic and nitrogen species in soil aquifer treatment process." Water Science and Technology 50, no. 2 (July 1, 2004): 255–61. http://dx.doi.org/10.2166/wst.2004.0138.

Full text
Abstract:
Soil aquifer treatment (SAT) is a promising technique for wastewater reclamation and reuse. This treatment strategy takes advantage of physicochemical and biological processes in the subsurface. The model employed in this study is based on MODFLOW-SURFACT (HydroGeoLogic, Inc.), a three-dimensional model for variably saturated flow and reactive mass transport. The model accounts for reactions including the nitrification of ammonium, the denitrification of nitrate, and the oxidation of organic carbon. Concentration of dissolved oxygen and biomasses involved in aerobic and anaerobic biological reactions forms the basis for estimates of nonlinear reaction rates formulated using a multiple-Monod expression. Illustrative simulations were conducted in a two-dimensional cross-sectional domain, with unsaturated and saturated zones. They examine the effects that site and operational conditions have on the performance of a SAT system. The parameters and conditions of concern included length of the wet/dry cycle, ground surface condition, and infiltration rate. From the simulations, we found that organic carbon was effectively removed in all cases. The availability of oxygen was a key factor in predicting the production and removal of nitrate. Overall, the model successfully described the fate and transport of the key constituents during the wet/dry operational periods in both unsaturated and saturated subsurface.
APA, Harvard, Vancouver, ISO, and other styles
48

Rücker, Carsten. "Open Source Software Library for Thermo-Hydro-Mechanical Coupled Processes in Python." Safety of Nuclear Waste Disposal 1 (November 10, 2021): 185–86. http://dx.doi.org/10.5194/sand-1-185-2021.

Full text
Abstract:
Abstract. This contributed poster shows the current state of development of a finite element implementation as part of an open source software library (OSSL) for the simulation of thermo-hydro-mechanical (THM) coupled processes. The reliable handling of numerical methods is fundamental for the understanding of scientific interrelationships and thus, a crucial prerequisite for modeling THM scenarios, as well as for the understanding and evaluation of preliminary safety investigations during the site selection process for the storage of high-level radioactive waste. There are several motivations for developing an in-house OSSL, which will allow us to: Build capacity and maintenance within BASE (Federal Office for the Safety of Nuclear Waste Management) regarding issues of the numerical modeling of safety-relevant aspects on the long-term safety analyses specified by the German legislator in the site selection process. Develop a collection of known benchmarks and evaluation examples for the comparison of different software tools, applying a uniform interface to simplify the use of the available highly specialized open source codes. Diversify the testing possibilities regarding the preliminary safety investigations by means of our own, independent modeling software. Document basic THM scenarios for internal or, if necessary, public technical training, e.g., density-driven fluid flow (Fig. 1), convergence in salt, temperature propagation in the repository area, crack development, diffusive or advective mass transport. Ensure transparency and, in principle, might allow for appropriately proven-quality (validated) and documented simulation tools for the public regarding questions about the preliminary safety investigations during the site selection process. The development of the OSSL is mainly based on the scripting language Python, which allows the necessary flexibility for the diverse fields of application and at the same time enables maximum transparency for all aspects of the source code. To ensure the high quality of the software, state of the art development tools are used (e.g., version control, automated tests, and documentation generation). Figure 1 shows our preliminary simulation results of the so-called Elder problem (Elder, 1967), a popular standard benchmark for thermo-hydrogeological coupling in which fluid motion in a porous medium is driven by buoyancy forces.
APA, Harvard, Vancouver, ISO, and other styles
49

Fabbri, Paolo, Carlo Gaetan, Luca Sartore, and Nico Dalla Libera. "Subsoil Reconstruction in Geostatistics beyond Kriging: A Case Study in Veneto (NE Italy)." Hydrology 7, no. 1 (March 7, 2020): 15. http://dx.doi.org/10.3390/hydrology7010015.

Full text
Abstract:
The reconstruction of hydro-stratigraphic units in subsoil (a general term indicating all the materials below ground level) plays an important role in the assessment of soil heterogeneity, which is a keystone in groundwater flow and transport modeling. A geostatistical approach appears to be a good way to reconstruct subsoil, and now other methods besides the classical indicator (co)kriging are available as alternative approximations of the conditional probabilities. Some of these techniques take specifically into account categorical variables as lithologies, but they are computationally prohibitive. Moreover, the stage before subsoil prediction/simulation can be very informative from a hydro-stratigraphic point of view, as the detailed transiogram analysis of this paper demonstrates. In this context, an application of the spMC package for the R software is presented by using a test site located within the Venetian alluvial plain (NE Italy). First, a detailed transiogram analysis was conducted, and then a maximum entropy approach, based on transition probabilities, named Markovian-type Categorical Prediction (MCP), was applied to approximate the posterior conditional probabilities. The study highlights some advantages of the presented approach in term of hydrogeological knowledge and computational efficiency. The spMC package couples transiogram analysis with a maximum entropy approach by taking advantage of High-Performance Computing (HPC) techniques. These characteristics make the spMC package useful for simulating hydro-stratigraphic units in subsoil, despite the use of a large number of lithologies (categories). The results obtained by spMC package suggest that this software should be considered a good candidate for simulating subsoil lithological distributions, especially of limited areas.
APA, Harvard, Vancouver, ISO, and other styles
50

Perminov, Nikolay A. "The geotechnical modeling of interaction between a large-sized lowered structure and heterogeneous soil environment in the process of embedment." Vestnik MGSU, no. 2 (February 2022): 188–204. http://dx.doi.org/10.22227/1997-0935.2022.2.188-204.

Full text
Abstract:
Introduction. The use of extremely deep and large underground spaces in case of complex geoengineering and hydrogeological conditions is a challenging geotechnical task. The accumulated experience of using the embedment method, that entails the construction of a geotechnical and hydrotechnical enclosure, which is at the same time a reliable bearing structure, has proven a strong technical and economic potential and good prospects for expanding the scope of its application. The study of interaction between large-sized reinforced concrete shells at the stages of their construction in heterogeneous soil environments allowed expanding the scope of their rational use in the subterranean construction that deals with transport and engineering infrastructure facilities. The defect-free construction of a subterranean structure of this type requires a consolidated solution for complex nonlinear design and geotechnical problems. Materials and methods. The non-stationarity of processes of interaction between a massive structure and the soil environment, as well as the heterogeneity of the environment itself necessitate the development of methods of adaptive control over the stress-strain state of the system that encompasses “a large gravitational body and the heterogeneous environment”. The consolidated geotechnical and structural analysis allows simulating processes of interaction between the shell and the soil environment and prognosticating the parameters of adaptive control over the stress-strain state of the system. Results. The application of adaptive stress-strain control methods lays the groundwork for a defect-free lifecycle of a structure at the stages of its construction and operation in problematic soils under man-induced impacts. Conclusions. Unlike the traditional approach, the method, proposed by the author, encompasses the fundamentals of a new concept for assessing the interaction between large-sized structures, embedded in variable strength soils, taking into account the irregularity of the embedment mode and results of its practical implementation focused on the geotechnical support of a defect-free life cycle of unique large-sized subterranean structures at the construction stage.
APA, Harvard, Vancouver, ISO, and other styles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography