Local scale PC-oriented Eulerian pollutant transport model PolTran-1-2

2000 ◽  
Vol 14 (1/2/3/4/5/6) ◽  
pp. 217 ◽  
Author(s):  
Dimiter G. Atanassov
Keyword(s):  
Transport Model ◽  
Pollutant Transport ◽  
Local Scale

scholarly journals Comparison of three stream tube models predicting field-scale solute transport

1997 ◽  
Vol 1 (4) ◽  
pp. 873-893 ◽  
Author(s):  
D. Jacques ◽  
J. Vanderborght ◽  
D. Mallants ◽  
D.-J. Kim ◽  
H. Vereecken ◽  
...  
Keyword(s):  
Solute Transport ◽  
Transport Model ◽  
Local Scale ◽  
Transfer Model ◽  
Transport Parameters ◽  
Field Scale ◽  
Stream Tube ◽  
Solute Dispersion ◽  
Measurement Volume ◽  
Piston Flow

Abstract. In this paper the relation between local- and field-scale solute transport parameters in an unsaturated soil profile is investigated. At two experimental sites, local-scale steady-state solute transport was measured in-situ using 120 horizontally installed TDR probes at 5 depths. Local-scale solute transport parameters determined from BTCs were used to predict field-scale solute transport using stochastic stream tube models (STM). Local-scale solute transport was described by two transport models: (1) the convection-dispersion transport model (CDE), and (2) the stochastic convective lognormat transfer model (CLT). The parameters of the CDE-model were found to be lognormally distributed, whereas the parameters of the CLT model were normally distributed. Local-scale solute transport heterogeneity within the measurement volume of a TDR-probe was an important factor causing field-scale solute dispersion. The study of the horizontal scale-dependency revealed that the variability in the solute transport parameters contributes more to the field-scale dispersion at deeper depths than at depths near the surface. Three STMs were used to upscale the local transport parameters: (i) the stochastic piston flow STM-I assuming local piston flow transport, (ii) the convective-dispersive STM-II assuming local CDE transport, and (iii) the stochastic convective lognormal STM-III assuming local CLT. The STM-I considerably underpredicted the field-scale solute dispersion indicating that local-scale dispersion processes, which are captured within the measurement volume of the TDR-probe, are important to predict field-scale solute transport. STM-II and STM-III both described the field-scale breakthrough curves (BTC) accurately if depth dependent parameters were used. In addition, a reasonable description of the horizontal variance of the local BTCs was found. STM-III was (more) superior to STM-II if only one set of parameters from one depth is used to predict the field-scale solute BTCs at several depths. This indicates that the local-scale solute transport process, as measured with TDR in this study, is in agreement with the CLT-hypothesis.

scholarly journals Coastal modelling with a GIS bathymetric module

2013 ◽  
Vol 4 (1) ◽  
pp. 51-73
Keyword(s):  
3D Model ◽  
Transport Model ◽  
Pollutant Transport ◽  
Coastal Areas ◽  
Coastal Modelling ◽  
Rectangular Grids ◽  
Gis Environment ◽  
Arcview Gis

A 3D hydrodynamic/pollutant transport model was used to simulate the currents and pollutant transport in coastal areas. The bathymetric and shoreline data was provided to the model via a GIS module that operates in the ArcView GIS environment. The module is efficient and capable of generating bathymetric rectangular grids and shorelines of different resolution for open and closed boundary scenarios that can automatically be read by the coastal model. This ability could improve the basic patterns and relationships of the model such as grid dependency. The functionality of the 3D model with the GIS module is illustrated in a number of coastal areas in Greece.

Risk assessment using stochastic modeling of pollutant transport in landfill clay liners

1999 ◽  
Vol 39 (10-11) ◽  
pp. 337-341 ◽  
Author(s):  
Irene M.-C. Lo ◽  
Wendy K.-W. Law ◽  
Helen M. Shen
Keyword(s):  
Risk Assessment ◽  
Monte Carlo Simulation ◽  
Stochastic Modeling ◽  
Transport Model ◽  
Pollutant Transport ◽  
Design Parameters ◽  
Contaminant Concentration ◽  
Clay Liners ◽  
Clay Liner ◽  
Advection Dispersion

Risk assessment of landfil systems using Monte Carlo simulation in the prediction of groundwater contamination underneath a landfill insulated by clay liner is presented. The advantage of applying stochastic modeling is that uncertainties associated with various design parameters can be taken into account in the prediction of pollutant transport through the clay liner. A model based on a pollutant transport model considering advection, dispersion and sorption is developed in this study. The design parameters with their corresponding distribution forms are fed into the simulation model. The probability of the contaminant concentration in the groundwater underneath the landfill exceeding a predetermined value is used for risk assessment.

A wind driven three-dimensional pollutant transport model

2005 ◽  
Vol 20 (10) ◽  
pp. 1323-1333 ◽  
Author(s):  
I.K. Tsanis ◽  
D. Hurdowar-Castro
Keyword(s):  
Transport Model ◽  
Three Dimensional ◽  
Pollutant Transport

scholarly journals A hierarchical approach on groundwater-surface water interaction in wetlands along the upper Biebrza River, Poland

2012 ◽  
Vol 16 (7) ◽  
pp. 2329-2346 ◽  
Author(s):  
C. Anibas ◽  
B. Verbeiren ◽  
K. Buis ◽  
J. Chormański ◽  
L. De Doncker ◽  
...  
Keyword(s):  
Surface Water ◽  
Water Exchange ◽  
Hyporheic Zone ◽  
Transport Model ◽  
Local Scale ◽  
Organic Soils ◽  
Hierarchical Approach ◽  
Field Methods ◽  
Water Interaction ◽  
Groundwater Surface Water Interaction

Abstract. As recognized in the European Water Framework Directive, groundwater-dependent wetlands and their diverse ecosystems have important functions which need to be protected. The vegetation in such habitats is often dependent on quality, quantity and patterns of river discharge and groundwater-surface water interaction on a local or reach scale. Since groundwater-surface water exchange studies on natural rivers and wetlands with organic soils are scarce, more functional analysis is needed. To this end we combined different field methods including piezometer nests, temperature as tracer and seepage meter measurements. Some of these measurements were used as inputs and/or as validation for the numerical 1-D heat transport model STRIVE. In transient mode the model was used to calculate spatially distributed vertical exchange fluxes from temperature profiles measured at the upper Biebrza River in Poland over a period of nine months. Time series of estimated fluxes and hydraulic head gradients in the hyporheic zone were used to estimate the temporal variability of groundwater-surface water exchange. This paper presents a hierarchical approach for quantifying and interpreting groundwater-surface water interaction in space and time. The results for the upper Biebrza show predominantly upward water fluxes, sections of recharge, however, exist along the reach. The fluxes depend more on hydraulic gradients than on riverbed conductivity. This indicates that the fluvio-plain scale is required for interpreting the exchange fluxes, which are estimated on a local scale. The paper shows that a conceptual framework is necessary for understanding the groundwater-surface water interaction processes, where the exchange fluxes are influenced by local factors like the composition of the riverbed and the position of the measurement on a local scale, and by regional factors like the hydrogeology and topography on a fluvio-plain scale. The hierarchical methodology increases the confidence in the estimated exchange fluxes and improves the process understanding. The accuracy of the measurements and related uncertainties, however, remain challenges for wetland environments. Gaining quantitative information on groundwater-surface water interaction can improve modeling confidence and as a consequence helps to develop effective procedures for management and conservation of valuable groundwater dependent wetlands.

scholarly journals Statistical atmospheric inversion of local gas emissions by coupling the tracer release technique and local-scale transport modelling: a test case with controlled methane emissions

2017 ◽  
Vol 10 (12) ◽  
pp. 5017-5037 ◽  
Author(s):  
Sébastien Ars ◽  
Grégoire Broquet ◽  
Camille Yver Kwok ◽  
Yelva Roustan ◽  
Lin Wu ◽  
...  
Keyword(s):  
Transport Model ◽  
Atmospheric Transport ◽  
Local Scale ◽  
Emission Rates ◽  
Gaussian Plume Model ◽  
Transport Modelling ◽  
Atmospheric Transport Modelling ◽  
Release Technique ◽  
Gaussian Plume ◽  
Atmospheric Concentrations

Abstract. This study presents a new concept for estimating the pollutant emission rates of a site and its main facilities using a series of atmospheric measurements across the pollutant plumes. This concept combines the tracer release method, local-scale atmospheric transport modelling and a statistical atmospheric inversion approach. The conversion between the controlled emission and the measured atmospheric concentrations of the released tracer across the plume places valuable constraints on the atmospheric transport. This is used to optimise the configuration of the transport model parameters and the model uncertainty statistics in the inversion system. The emission rates of all sources are then inverted to optimise the match between the concentrations simulated with the transport model and the pollutants' measured atmospheric concentrations, accounting for the transport model uncertainty. In principle, by using atmospheric transport modelling, this concept does not strongly rely on the good colocation between the tracer and pollutant sources and can be used to monitor multiple sources within a single site, unlike the classical tracer release technique. The statistical inversion framework and the use of the tracer data for the configuration of the transport and inversion modelling systems should ensure that the transport modelling errors are correctly handled in the source estimation. The potential of this new concept is evaluated with a relatively simple practical implementation based on a Gaussian plume model and a series of inversions of controlled methane point sources using acetylene as a tracer gas. The experimental conditions are chosen so that they are suitable for the use of a Gaussian plume model to simulate the atmospheric transport. In these experiments, different configurations of methane and acetylene point source locations are tested to assess the efficiency of the method in comparison to the classic tracer release technique in coping with the distances between the different methane and acetylene sources. The results from these controlled experiments demonstrate that, when the targeted and tracer gases are not well collocated, this new approach provides a better estimate of the emission rates than the tracer release technique. As an example, the relative error between the estimated and actual emission rates is reduced from 32 % with the tracer release technique to 16 % with the combined approach in the case of a tracer located 60 m upwind of a single methane source. Further studies and more complex implementations with more advanced transport models and more advanced optimisations of their configuration will be required to generalise the applicability of the approach and strengthen its robustness.

scholarly journals Finite volume method solution of pollutant transport in catchment sheet flow

2013 ◽  
Vol 45 (2) ◽  
pp. 182-189
Author(s):  
Gokmen Tayfur ◽  
Zhiguo He ◽  
Qihua Ran
Keyword(s):  
Finite Volume Method ◽  
Finite Volume ◽  
Active Layer ◽  
Overland Flow ◽  
Transport Model ◽  
Pollutant Transport ◽  
Water Volume ◽  
Sheet Flow ◽  
Advection Diffusion Equation ◽  
Volume Method

A finite volume numerical method was employed in the solution of two-dimensional pollutant transport in catchment sheet flow. The full dynamic wave constituted the sheet flow while the advection–diffusion equation with sink/source terms was the pollutant transport model. It is assumed that the solute in the surface active layer is uniformly distributed and the exchange rate of the solute between the active layer and overland flow are proportional to the difference between the concentrations in soil and water volume. Decrease of the solute transfer rate in the active surface layer caused by the transfer of solutes from soil to the overlying runoff is assumed to follow an exponential law. The equations governing sheet flow and pollutant transport are discretized using the finite volume method in space and an implicit backward difference scheme in time. The model was subjected to several numerical tests involving varying microtopographic surface, roughness, and infiltration. The results revealed that spatially varying microtopography plays an important role unlike the roughness and infiltration with respect to the total pollutant rate from the outlet of a catchment.

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