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Cvetkovic, Vladimir
Publications (10 of 24) Show all publications
Zech, A., Attinger, S., Bellin, A., Cvetkovic, V., Dietrich, P., Fiori, A., . . . Dagan, G. (2019). A Critical Analysis of Transverse Dispersivity Field Data. Ground Water, 57(4), 632-639
Open this publication in new window or tab >>A Critical Analysis of Transverse Dispersivity Field Data
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2019 (English)In: Ground Water, ISSN 0017-467X, E-ISSN 1745-6584, Vol. 57, no 4, p. 632-639Article in journal (Refereed) Published
Abstract [en]

Transverse dispersion, or tracer spreading orthogonal to the mean flow direction, which is relevant e.g, for quantifying bio-degradation of contaminant plumes or mixing of reactive solutes, has been studied in the literature less than the longitudinal one. Inferring transverse dispersion coefficients from field experiments is a difficult and error-prone task, requiring a spatial resolution of solute plumes which is not easily achievable in applications. In absence of field data, it is a questionable common practice to set transverse dispersivities as a fraction of the longitudinal one, with the ratio 1/10 being the most prevalent. We collected estimates of field-scale transverse dispersivities from existing publications and explored possible scale relationships as guidance criteria for applications. Our investigation showed that a large number of estimates available in the literature are of low reliability and should be discarded from further analysis. The remaining reliable estimates are formation-specific, span three orders of magnitude and do not show any clear scale-dependence on the plume traveled distance. The ratios with the longitudinal dispersivity are also site specific and vary widely. The reliability of transverse dispersivities depends significantly on the type of field experiment and method of data analysis. In applications where transverse dispersion plays a significant role, inference of transverse dispersivities should be part of site characterization with the transverse dispersivity estimated as an independent parameter rather than related heuristically to longitudinal dispersivity.

Place, publisher, year, edition, pages
WILEY, 2019
National Category
Geotechnical Engineering
Identifiers
urn:nbn:se:kth:diva-255479 (URN)10.1111/gwat.12838 (DOI)000474284400013 ()30381834 (PubMedID)2-s2.0-85058855127 (Scopus ID)
Note

QC 20190919

Available from: 2019-09-19 Created: 2019-09-19 Last updated: 2019-09-19Bibliographically approved
Vigouroux, G., Destouni, G., Jonsson, A. & Cvetkovic, V. (2019). A scalable dynamic characterisation approach for water quality management in semi-enclosed seas and archipelagos. Marine Pollution Bulletin, 139, 311-327
Open this publication in new window or tab >>A scalable dynamic characterisation approach for water quality management in semi-enclosed seas and archipelagos
2019 (English)In: Marine Pollution Bulletin, ISSN 0025-326X, E-ISSN 1879-3363, Vol. 139, p. 311-327Article in journal (Refereed) Published
Abstract [en]

In semi-enclosed seas, eutrophication may affect both the coastal waters and the whole sea. We develop and test a modelling approach that can account for nutrient loads from land as well as for influences and feedbacks on water quality across the scales of a whole semi-enclosed sea and its coastal zones. We test its applicability in the example cases of the Baltic Sea and one of its local archipelagos, the Archipelago Sea. For the Baltic Sea scale, model validation shows good representation of surface water quality dynamics and a generally moderate model performance for deeper waters. For the Archipelago Sea, management scenario simulations show that successful sea measures may have the most important effects on coastal water quality. This highlights the need to consistently account for whole-sea water-quality dynamics and management effects, in addition to effects of land drivers, in modelling for characterisation and management of local water quality.

Place, publisher, year, edition, pages
PERGAMON-ELSEVIER SCIENCE LTD, 2019
Keywords
Eutrophication modelling, Coastal management, Nutrient dynamics, Semi-enclosed seas, Land-sea continuum
National Category
Oceanography, Hydrology and Water Resources
Identifiers
urn:nbn:se:kth:diva-245154 (URN)10.1016/j.marpolbul.2018.12.021 (DOI)000458227800037 ()30686432 (PubMedID)2-s2.0-85059574257 (Scopus ID)
Note

QC 20190308

Available from: 2019-03-08 Created: 2019-03-08 Last updated: 2019-03-08Bibliographically approved
Paul, S., Oppelstrup, J., Thunvik, R., Mango Magero, J., DDumba Walakira, D. & Cvetkovic, V. (2019). Bathymetry Development and Flow Analyses Using Two-Dimensional Numerical Modeling Approach for Lake Victoria. Fluids, 4(4), 1-21
Open this publication in new window or tab >>Bathymetry Development and Flow Analyses Using Two-Dimensional Numerical Modeling Approach for Lake Victoria
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2019 (English)In: Fluids, ISSN 2311-5521, Vol. 4, no 4, p. 1-21Article in journal (Refereed) [Artistic work] Published
Abstract [en]

This study explored two-dimensional (2D) numerical hydrodynamic model simulations of Lake Victoria. Several methods were developed in Matlab to build the lake topography. Old depth soundings taken in smaller parts of the lake were combined with more recent extensive data to produce a smooth topographical model. The lake free surface numerical model in the COMSOL Multiphysics (CM) software was implemented using bathymetry and vertically integrated 2D shallow water equations. Validated by measurements of mean lake water level, the model predicted very low mean flow speeds and was thus close to being linear and time invariant, allowing long-time simulations with low-pass filtered inflow data. An outflow boundary condition allowed an accurate simulation to achieve the lake’s steady state level. The numerical accuracy of the linear measurement of lake water level was excellent.

Place, publisher, year, edition, pages
Basel, Switzerland: , 2019
Keywords
methods of lake bathymetry; shallow water equations; lake hydrodynamics; numerical accuracy; steady-state analysis; water-level validation
National Category
Water Engineering
Research subject
Applied and Computational Mathematics, Numerical Analysis; Civil and Architectural Engineering, Hydraulic and Hydrologic Engineering; Land and Water Resources Engineering
Identifiers
urn:nbn:se:kth:diva-263581 (URN)10.3390/fluids4040182 (DOI)
Projects
PhD project
Funder
Lars Erik Lundberg Scholarship Foundation
Note

QC 20191106

Available from: 2019-11-06 Created: 2019-11-06 Last updated: 2019-11-06Bibliographically approved
Zou, L., Håkansson, U. & Cvetkovic, V. (2019). Cement grout propagation in 2D fracture networks: impact of rheology. In: Sergio A.B. da Fontoura, Ricardo Jose Rocca, José Pavón Mendoza (Ed.), Proceedings in Earth and Geosciences: Rock Mechanics for Natural Resources and Infrastructure Development. Paper presented at The 14th ISRM congress, September 13 to 18, 2019 Brazil (pp. 2486-2493). CRC Press, 6
Open this publication in new window or tab >>Cement grout propagation in 2D fracture networks: impact of rheology
2019 (English)In: Proceedings in Earth and Geosciences: Rock Mechanics for Natural Resources and Infrastructure Development / [ed] Sergio A.B. da Fontoura, Ricardo Jose Rocca, José Pavón Mendoza, CRC Press, 2019, Vol. 6, p. 2486-2493Conference paper, Published paper (Refereed)
Abstract [en]

Cement grouts propagation into a two-dimensional water-saturated fracture networks with different values of rheological properties are simulated by using an extended two-phase flow model. The cement grouts are typical non-Newtonian fluids that contain yield stress, which are often assumed as Bingham fluids. The aim of this study is to investigate the impact of Bingham rheological properties, i.e. yield stress and plastic viscosity, on cement gouts propagation in two-dimensional fracture networks. The results generally show that the rheological properties of cement grouts, i.e. yield stress and plastic viscosity, significantly affect cement grouts propagation in the fracture network. The propagation rate in the fracture networks reduces with the increase of the yield stress and the plastic viscosity of the cement grouts.

Place, publisher, year, edition, pages
CRC Press, 2019
Keywords
rock grouting; cement grout; fracture networks; rheology
National Category
Civil Engineering
Research subject
Civil and Architectural Engineering, Soil and Rock Mechanics
Identifiers
urn:nbn:se:kth:diva-260046 (URN)
Conference
The 14th ISRM congress, September 13 to 18, 2019 Brazil
Funder
Rock Engineering Research Foundation (BeFo)
Note

QC 20190930

Available from: 2019-09-24 Created: 2019-09-24 Last updated: 2019-09-30Bibliographically approved
Zou, L., Håkansson, U. & Cvetkovic, V. (2019). Cement grout propagation in two-dimensional fracture networks: Impact of structure and hydraulic variability. International Journal of Rock Mechanics And Mining Sciences, 115, 1-10
Open this publication in new window or tab >>Cement grout propagation in two-dimensional fracture networks: Impact of structure and hydraulic variability
2019 (English)In: International Journal of Rock Mechanics And Mining Sciences, ISSN 1365-1609, E-ISSN 1873-4545, Vol. 115, p. 1-10Article in journal (Refereed) Published
Abstract [en]

Analysis of cement grout propagation in water-saturated two-dimensional discrete fracture networks is presented in this study. A two-phase flow model for Bingham fluids flow in a single saturated fracture is extended to simulate cement grouts propagation in saturated networks. Using this extended model, the impacts of network structure and hydraulic variability, i.e., network geometry and aperture distribution, on the propagation process are investigated through numerical simulations. Cement grout propagation in 50 realizations of a two-dimensional discrete fracture network (2D DFN) are simulated with different cases of aperture variability, i.e. constant aperture, uncorrelated and length-correlated heterogeneous apertures following a truncated lognormal distribution. The results indicate that network structure and hydraulic variability significantly affect the grout propagation in 2D DFN systems. The randomized network structure and uncorrelated heterogeneous apertures significantly delay the propagation rate and largely increase the variability range of the propagation volume fraction. In contrast, in the case with length-correlated heterogeneous apertures, the propagation rate increases, while the variability range and rate of change of the propagation volume fraction decreases. The extended two-phase flow model for fracture networks and the simulation results presented in this work are useful for basic understanding of the processes relevant for design, monitoring and execution of rock grouting.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Rock grouting, Bingham fluids, Two-phase flow, Discrete fracture networks, Propagation volume fraction, Uncertainty quantification
National Category
Geophysical Engineering
Identifiers
urn:nbn:se:kth:diva-245902 (URN)10.1016/j.ijrmms.2019.01.004 (DOI)000459008800001 ()2-s2.0-85060117035 (Scopus ID)
Note

QC 20190311

Available from: 2019-03-11 Created: 2019-03-11 Last updated: 2019-03-11Bibliographically approved
Zou, L., Håkansson, U. & Cvetkovic, V. (2019). Characterization of effective transmissivity for cement grout flow in rock fractures. In: Proceedings of Nordic Grouting Symposium 2019: . Paper presented at Nordic Grouting Symposium 2019, 02-03 Sep 2019, Hilton Helsinki Airport, Vantaa, Finland.
Open this publication in new window or tab >>Characterization of effective transmissivity for cement grout flow in rock fractures
2019 (English)In: Proceedings of Nordic Grouting Symposium 2019, 2019Conference paper, Published paper (Refereed)
Abstract [en]

Cement grouting has been widely used in rock engineering. Proper characterization of the effective transmissivity for cement grout flow in rock fractures is primarily important for the design of rock grouting. In practice, the hydraulic transmissivity of groundwater flow in rock fractures characterized by hydraulic tests, i.e., pumping or slug test, is often used for the design of rock grouting. However, cement grouts used in rock grouting practice are typical non-Newtonian fluids contain yield stress, which has different effective transmissivity from the Newtonian groundwater. Therefore, using the groundwater transmissivity characterized by hydraulic tests may cause significant uncertainty in modeling and design of cement rock grouting. In this study, we focus on the effective transmissivity of non-Newtonian cement grout flow in a single fracture, aiming to illustrate the difference between the effective transmissivity of non-Newtonian cement grouts and the hydraulic transmissivity of the Newtonian groundwater. The cement grout is assumed as a Bingham fluid. The theoretical solution for the effective transmissivity of Bingham grout for homogeneous fractures is presented. This solution is compared with the theoretical hydraulic transmissivity, i.e., the cubic law. The results generally illustrate the significant differences between the effective transmissivity of non-Newtonian cement grouts and the hydraulic transmissivity of groundwater. The effective transmissivity of non-Newtonian cement grout is nonlinear which a function of injection pressure. Using the hydraulic transmissivity for rock grouting may underestimate the propagation length of the cement grout in rock fractures. The obtained result is helpful for rock grouting design in practice to reduce the potential uncertainties caused by using the hydraulic transmissivity.

Keywords
Cement grouting; Effective transmissivity: Hydraulic aperture: Propagation length
National Category
Infrastructure Engineering
Research subject
Civil and Architectural Engineering
Identifiers
urn:nbn:se:kth:diva-257893 (URN)
Conference
Nordic Grouting Symposium 2019, 02-03 Sep 2019, Hilton Helsinki Airport, Vantaa, Finland
Funder
Rock Engineering Research Foundation (BeFo)
Note

QC 20190917

Available from: 2019-09-08 Created: 2019-09-08 Last updated: 2019-09-17Bibliographically approved
Chen, Y., Vigouroux, G., Bring, A., Cvetkovic, V. & Destouni, G. (2019). Dominant Hydro-Climatic Drivers of Water Temperature, Salinity, and Flow Variability for the Large-Scale System of the Baltic Coastal Wetlands. Water, 11(3), Article ID 552.
Open this publication in new window or tab >>Dominant Hydro-Climatic Drivers of Water Temperature, Salinity, and Flow Variability for the Large-Scale System of the Baltic Coastal Wetlands
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2019 (English)In: Water, ISSN 2073-4441, E-ISSN 2073-4441, Vol. 11, no 3, article id 552Article in journal (Refereed) Published
Abstract [en]

For the large-scale coastal wetland system of the Baltic Sea, this study develops a methodology for investigating if and to what degree the variability and changes in certain hydro-climatic drivers control key coastal-marine physical conditions. The studied physical conditions include: (a) water temperature, (b) water salinity, and (c) flow structures (magnitudes and directions of flows between marine basins and the associated coastal zones and wetlands). We use numerical simulations of three hydro-climatically distinct cases to investigate the variations in hydro-climatic drivers and the resulting physical conditions (a-c) among the cases. The studied hydro-climatic forcing variables are: net surface heat flux, wind conditions, saltwater influx from the North Sea, and freshwater runoff from land. For these variables, the available observation-based data show that the total runoff from land is significantly and positively correlated with precipitation on the sea itself, and negatively correlated with saltwater influx from the North Sea to the Baltic Sea. Overall, the physical condition (a-c) variability in the Baltic Sea and its coastal zones is found to be pairwise well-explained by simulation case differences as follows: (a) Net heat flux is a main control of sea water temperature. (b) Runoff from land, along with the correlated salt water influx from the North Sea, controls average sea salinity; with the variability of local river discharges shifting some coastal zones to deviate from the average sea condition. (c) Wind variability and change control the Baltic Sea flow structure, primarily in terms of flow magnitude and less so in terms of flow direction. For specific coastal wetland zones, considerable salinity differences from average Baltic Sea conditions (due to variability in local river discharges) are found for the coasts of Finland and Estonia, while the coastal wetland zones of south-eastern Sweden, and of Estonia and Latvia, emerge as particularly sensitive to wind shifts.

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
coastal wetlands, Baltic sea, hydro-climatic variability and change, physical sea changes, FVCOM
National Category
Water Engineering
Identifiers
urn:nbn:se:kth:diva-251352 (URN)10.3390/w11030552 (DOI)000464534200002 ()2-s2.0-85065024420 (Scopus ID)
Note

QC 20190521

Available from: 2019-05-21 Created: 2019-05-21 Last updated: 2019-05-23Bibliographically approved
Chen, Y., Cvetkovic, V. & Destouni, G. (2019). Scenarios of Nutrient-Related Solute Loading and Transport Fate from Different Land Catchments and Coasts into the Baltic Sea. Water, 11(7), Article ID 1407.
Open this publication in new window or tab >>Scenarios of Nutrient-Related Solute Loading and Transport Fate from Different Land Catchments and Coasts into the Baltic Sea
2019 (English)In: Water, ISSN 2073-4441, E-ISSN 2073-4441, Vol. 11, no 7, article id 1407Article in journal (Refereed) Published
Abstract [en]

This study uses controlled numerical experimentation to comparatively simulate and investigate solute transport and concentration responses and patterns in the Baltic Sea for various solute releases from the land through two different coastal cases. These cases are the Swedish Kalmar County coast and the Polish coast of the Vistula River outlet. For equivalent solute releases, the coastal flow conditions and their interactions with main marine currents determine the local coastal solute spreading, while the overall spreading over the Baltic Sea is similar for the two coastal cases, despite their large local differences. For nutrient-proportional solute release scenarios, the highly-populated Vistula catchment yields much greater total, but smaller per-capita nutrient impacts, in the Baltic Sea than the Kalmar County catchment. To be as low as from the Vistula catchment, the per-capita nutrient contribution from Kalmar County would have to be reduced much more than required on average per Swedish inhabitant by the Baltic Sea Action Plan. This highlights an unfairness issue in the per-capita distribution of nutrient load allowance among the Baltic countries, which needs to be considered and handled in further research and international efforts aimed to combat the Baltic Sea eutrophication.

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
solute transport, Baltic Sea, nutrient loads, coastal concentrations, marine concentrations, Baltic Sea Action Plan, FVCOM simulations
National Category
Oceanography, Hydrology and Water Resources
Identifiers
urn:nbn:se:kth:diva-257466 (URN)10.3390/w11071407 (DOI)000480632300092 ()
Note

QC 20190830

Available from: 2019-08-30 Created: 2019-08-30 Last updated: 2019-08-30Bibliographically approved
Levi, L., Cvetkovic, V. & Destouni, G. (2018). Data-driven analysis of nutrient inputs and transfers through nested catchments. Science of the Total Environment, 610, 482-494
Open this publication in new window or tab >>Data-driven analysis of nutrient inputs and transfers through nested catchments
2018 (English)In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 610, p. 482-494Article in journal (Refereed) Published
Place, publisher, year, edition, pages
Elsevier, 2018
National Category
Medical Image Processing
Identifiers
urn:nbn:se:kth:diva-216590 (URN)10.1016/j.scitotenv.2017.08.003 (DOI)000411897700049 ()28820979 (PubMedID)2-s2.0-85027401440 (Scopus ID)
Note

QC 20171123

Available from: 2017-11-23 Created: 2017-11-23 Last updated: 2017-11-23Bibliographically approved
Zou, L., Cvetkovic, V., Jing, L. & Ivars, D. M. (2018). Impact of Normal Stress Caused Closure on Fluid Flow and Solute Retention in Rock Fractures. In: : . Paper presented at The International Conference on Coupled Processes in Fractured Geological Media: Observation, Modeling, and Application (CouFrac).CouFrac – November 12-14, 2018, Wuhan, China..
Open this publication in new window or tab >>Impact of Normal Stress Caused Closure on Fluid Flow and Solute Retention in Rock Fractures
2018 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Modeling of coupled hydro-mechanical and chemical (HMC) processes in fractured rocks is an important topic for many geoengineering projects.  Over the past decades, many efforts have been devoted to study the flow and transport in single fractures with consideration of mechanical effects. It is generally known that the mechanical effects, i.e. normal and shear deformation, significantly affect fluid flow and solute transport processes in rough-walled rock fractures since the deformation may largely alter the structure of fracture apertures that directly controls transmissivity. Due to complicated physical processes combined with complexity of geometry structures, many issues remain open questions, such as fracture surface roughness characterization, deformation dependence of transmissivity and advective transport in natural rock fractures. In this work, we attempt to investigate the impact of stress caused closure on fluid flow and solute advective transport in a rough-walled fracture through numerical modeling.  A rough-walled fracture model is created based on a laser-scanned rock surface. The Bandis’s model is used to describe the fracture closure subject to normal stress. The flow is modeled by solving Reynolds equation and the advective transport is simulated through Lagrangian particle tracking. The results show that the normal stress caused fracture closure creates asperity contacts and reduces the mean aperture, which significantly reduces transmissivity, and affects the travel time and transport resistance. With increases of normal stress, the specific surface area reduces nonlinearly due to the nonlinear closure. In practice, especially for important hydrogeological projects, e.g. nuclear waste disposal, it is important to consider the coupled HMC processes in design and risk assessment.

Keywords
normal stress; rock fracture; fluid flow; solute transport
National Category
Infrastructure Engineering Water Engineering Geophysical Engineering
Research subject
Civil and Architectural Engineering, Soil and Rock Mechanics; Land and Water Resources Engineering
Identifiers
urn:nbn:se:kth:diva-260378 (URN)
Conference
The International Conference on Coupled Processes in Fractured Geological Media: Observation, Modeling, and Application (CouFrac).CouFrac – November 12-14, 2018, Wuhan, China.
Note

QC 20190930

Available from: 2019-09-28 Created: 2019-09-28 Last updated: 2019-09-30Bibliographically approved
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