scholarly journals Groundwater age, brine migration, and large-scale solute transport in the Alberta Basin, Canada

Geofluids ◽  
2015 ◽  
Vol 15 (4) ◽  
pp. 608-620 ◽  
Author(s):  
I. Gupta ◽  
A. M. Wilson ◽  
B. J. Rostron
Keyword(s):  
Solute Transport ◽  
Large Scale ◽  
Groundwater Age ◽  
Brine Migration ◽  
Alberta Basin

scholarly journals Study on Fluorine Pollution in a Slag Yard

2019 ◽  
Vol 9 (5) ◽  
pp. 847
Author(s):  
Lide Wei ◽  
Changfu Wei ◽  
Sugang Sui
Keyword(s):  
Numerical Simulation ◽  
Experimental Investigation ◽  
Numerical Simulations ◽  
Solute Transport ◽  
Large Scale ◽  
Three Dimensional ◽  
Simulation Method ◽  
Laboratory Studies ◽  
Survey Results ◽  
Simulation Results

This paper suggests a large-scale three-dimensional numerical simulation method to investigate the fluorine pollution near a slag yard. The large-scale three-dimensional numerical simulation method included an experimental investigation, laboratory studies of solute transport during absorption of water by soil, and large-scale three-dimensional numerical simulations of solute transport. The experimental results showed that the concentrations of fluorine from smelting slag and construction waste soil were well over the discharge limit of 0.1 kg/m3 recommended by Chinese guidelines. The key parameters of the materials used for large-scale three-dimensional numerical simulations were determined based on an experimental investigation, laboratory studies, and soil saturation of survey results and back analyses. A large-scale three-dimensional numerical simulation of solute transport was performed, and its results were compared to the experiment results. The simulation results showed that the clay near the slag had a high saturation of approximately 0.9, consistent with the survey results. Comparison of the results showed that the results of the numerical simulation of solute transport and the test results were nearly identical, and that the numerical simulation results could be used as the basis for groundwater environmental evaluation.

scholarly journals The Effect of Heterogeneity on Large Scale Solute Transport in the Unsaturated Zone

1989 ◽  
Vol 20 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Georgia Destouni ◽  
Vladimir Cvetkovic
Keyword(s):  
Solute Transport ◽  
Random Fields ◽  
Unsaturated Zone ◽  
Large Scale ◽  
Control Flow ◽  
Stochastic Methods ◽  
Solute Flux ◽  
Physical Parameters ◽  
Conductivity Water ◽  
Simple Stochastic Model

The effect of natural heterogeneity on large scale solute transport in the unsaturated zone is investigated using stochastic methods. Several of the physical parameters that control flow and solute transport in the unsaturated zone are regarded as random fields. Specifically, the influence of spatial variability in recharge applied on the surface, saturated hydraulic conductivity, water content at saturation and depth to the groundwater table, on solute flux into the groundwater, is illustrated. It is shown that the prediction of solute penetration into the groundwater through the unsaturated zone is significantly affected by the natural variability in the physical parameters. A simple stochastic model for the estimation of large scale solute flux through the unsaturated zone, is provided.

Streamwater time series coupled to groundwater age tracers informs the hydrologic partitioning of rainfall, the transient age distributions and their associated reactivity

2020 ◽  
Author(s):  
Jean Marçais ◽  
Jean-Raynald de Dreuzy ◽  
Louis A. Derry ◽  
Luca Guillaumot ◽  
Aurélie Guillou ◽  
...  
Keyword(s):  
Time Series ◽  
Large Scale ◽  
Groundwater Age ◽  
Stream Water ◽  
Critical Zone ◽  
Low Flow ◽  
Scale Model ◽  
Spatial And Temporal Variability ◽  
Dissolved Silica ◽  
Key Characteristics

<p><span>Intricated variabilities of stream water quality and of stream discharge can provide key insights of integrated processes occurring at the watershed scale. Yet it is difficult to disentangle the effects of hydrologic vs biogeochemical processes occurring in the different compartments of the critical zone, as well as the mixing associated to it. Here we developed a </span><span><em>quasi</em></span><span>-2D hillslope scale model able to represent the partitioning of precipitation into real evapotranspiration, shallow subsurface lateral flow and deeper groundwater flow circulation. Enhanced with an advective-dispersive particle tracking algorithm, the model delineates the age distributions of the associated flow lines and the resulting transient streamwater transit time distributions (TTDs). To relate geochemical datasets to TTDs, we connected the biogeochemical reactivity, spatially, to the compartment (regolith vs bedrock) and, in time, to the residence time of the different flowpaths.</span></p><p><span>We hypothesized that streamwater time series datasets (discharge and dissolved silica) and </span><span><em>in-situ</em></span><span> groundwater age tracers (CFCs) would build minimal but orthogonal information upon these partitioning and tracing processes. Applied to 4 different catchments in Brittany, we were able to represent the seasonal dynamics of evapotranspiration, discharge and dissolved silica (DSi) in rivers as well as CFC concentrations in aquifers once key characteristics of the watershed have been informed (evapotranspiration ratio, amount of water stored in the regolith and in the aquifer, bedrock transmissivity, weathering capacity). We found evapotranspiration ratio (ET/P) in average equal to 54% in agreement with independent, large-scale estimates (derived from the French climate Surfex model). The model also provides estimates for typical bedrock transmissivities around 5.10</span><sup><span>-4</span></sup><span> m</span><sup><span>2</span></sup><span>/s, mean transit times around 10 years with an important spatial and temporal variability, a</span><span>mount of stored water in average equal to 160 mm (resp. 3.10 m) in the regolith (resp. bedrock) and DSi weathering capacity of 0.3 mg/L/yr, which is in accordance with previous studies carried in crystalline contexts like Brittany [Leray et al. 2012, Kolbe et al. 2016, Marçais et al. 2018]. Simplifying the transient behavior of the catchment model with some analytical considerations enabled to directly inform these key characteristics with some properties of the measured datasets (e.g. average low flow rate, mean and standard deviation of the DSi time series, average CFC apparent ages). </span></p><p><span>This shows that these datasets can be used as standalone tracers and provide powerful indicators of critical zone characteristics described above. This also opens new avenues to spatialize the reactivity in the deep critical zone, and to integrate the information provided by different datasets (e.g. climatic forcing, discharge, solute concentrations, groundwater age tracers) measured in streams and in groundwater. Such modeling exercice paves the way toward an interdisciplinary understanding of the critical zone.</span></p>

Characterizing solute transport properties for a fractured carbonate aquifer using open-well dilution tests

2020 ◽  
Author(s):  
L. Jared West ◽  
Prodeo Y. Agbotui ◽  
Simon H. Bottrell
Keyword(s):  
Solute Transport ◽  
Transport Properties ◽  
Test Data ◽  
Large Scale ◽  
Electrical Conductance ◽  
Tracer Tests ◽  
Fractured Aquifer ◽  
Ambient Flow ◽  
Aquifer Systems ◽  
Single Well

<p>Single-well hydrogeophysical approaches have previously been applied to several fractured aquifers in the US and the UK, including karstic carbonate systems, in order to characterise solute transport. These approaches typically use single well hydraulic or tracer tests coupled with image or calliper logs to identify and characterise flowing features.  They have variously been used to estimate fracture/conduit aperture and porosity, permeability and/or groundwater velocities, in order to determine groundwater vulnerability or delineate wellhead protection areas.  Here, we outline a new workflow for application & analysis of single-well dilution tests for characterisation of fractured and karstic aquifers, and apply this to the Cretaceous Chalk aquifer, Yorkshire, UK.</p><p>Chalk aquifers typically have transmissivity that derives essentially from a well-developed network of fractures with solutionally-enhanced apertures and small conduits. Such features can lead to high groundwater velocities and high impacts of contamination on water quality. Knowledge of their solute transport properties is therefore important for delineating source protection areas, characterising contaminant fate and transport, determination of the effectiveness of aquifer remediation, and parameter estimation for models. In this work, single well dilution test data were used to characterise flow patterns in wells and infer properties such as the kinematic fracture porosity, and groundwater velocities. The single-well dilution technique relies on the interpretation of specific electrical conductance (SEC) contrasts between aquifer formation fluid and well fluid column following introduction of saline tracer in the well. Our workflow used both uniform injection (tracer introduced throughout the water column) and point injection (specific depth) tests in open wells under ambient flow conditions.  This workflow allowed sections of well showing horizontal versus vertical flow to be distinguished, and the magnitude of such flows and exchanges with the aquifer to be determined.  Flow within wells are then used to characterise aquifer properties as follows i) presence and direction of vertical hydraulic gradients ii) relative permeability and depth distribution of flowing features iii) in combination with hydraulic test data (e.g. overall well transmissivity) and geophysical logs, the porosity and permeability of the flowing features at each depth iv) in combination with local hydraulic head measurements in nearby wells, an estimate of groundwater velocities in the surrounding aquifer. We tested predicted fracture porosities and groundwater velocities against those measured in previous studies via large scale pumping tests and ambient flow well-to-well tracer tests.  The comparison suggests that the open-well dilution approach can provide reliable flowing porosities and groundwater velocities in fractured aquifer systems.</p>

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