Cast your vote
You can rate an item by clicking the amount of stars they wish to award to this item.
When enough users have cast their vote on this item, the average rating will also be shown.
Your vote was cast
Thank you for your feedback
Thank you for your feedback
MetadataShow full item record
TitleMETROPOL User's Guide
Translated Title[METROPOL Gebruikers handleiding.]
PubliekssamenvattingIn this report a description of METROPOL (MEthod for TRansport Of POLlutants) which simulates the three dimensional flow of groundwater, based on the finite element method is given. The model, METROPOL, consists of a package of computer programs for preprocessing, simulation and postprocessing. The preprocessing package includes programs for mesh generation and refinement. The simulation package contains programs for steady state and transient groundwater flow with constant density or transient flow with transport of dissolved salt or adsorbing and decaying species at low (tracer) concentrations. The postprocessing package includes programs for particle tracking and the generation of contour plots in two-dimensional cuts. This report serves as the user's guide for the different programs in the package. The general description of all modules of METROPOL is given in the chapters of this report. Finally the appendices provide complete and comprehensive descriptions of the different programs. Each of which can be used as a stand-alone user guide for the program described therein.<br>
Showing items related by title, author, creator and subject.
Modelling transport of waste material leachate in soils in support of environmental standardsvan Eijkeren JCH; Aalbers TG; de Wilde PGM (Rijksinstituut voor Volksgezondheid en Milieu RIVM, 1992-03-31)In the Netherlands a process of defining environmental standards is going on. These standards serve to protect the environment at the one hand, and to stimulate the reuse of rest-materials, e.g. ash from blast-furnaces, as building materials at the other hand. In order to come to an environmental legislation, quality-goals have been established for soil and (ground)water. Trustworthy and widely accepted testing methods are necessary to control the standards and to verify the quality-goals. Experimental verification has to be supported by theoretical modelling of physical and (bio-) chemical processes. Moreover, mathematical models are powerful tools for the prediction of the effect of the standards at the long range, when the duration or costs of experimental verification can be prohibitive. Therefore, a computer model that simulates the burden on an underlying soil of a reused waste-material has been developed. The model simulates coupled transport and behaviour of a set of chemical components. These components are assumed to be in mutual chemical equilibrium. Transport is assumed to occur by advection and dispersion. Equilibrium speciation of the components in aqueous solution is modelled by minimization of the chemical potential. The model code name is TRAMIN, from TRAnsport and MINeql. The MINEQL code, been attached to the transport module, MINimizes the chemical potential of a set of components in EQuiLibrium. The model has been used to simulate a laboratory experiment. From this application it appears that the existing data base should be extended with respect to complexation and precipitation and with respect to soil dependent sorption. Lack of a description for surface layer sorption prevented the modelling of iron-oxide, which was also a constituent of the percolate and the soil matrix. Further developments are continued, in close cooperation with the Agricultural University of Wageningen.<br>
Energiegebruik en emissies per vervoerwijzeBrink RMM van den; Wee GP van; LAE (1997-05-31)The aim of the study reported was to establish a basis for a realistic comparison of energy- efficiency to emissions from the different passenger and freight transport modes. Besides this report will also focus on of a modal shift on the effects on energy use and emissions. The energy use and emissions applied in the calculations arose from the production of fuels and electricity and yielded the following main conclusions: (1) Passenger transport by electric trains shows the lowest emission factors in 1995 compared to the other passenger transport modes. The city bus shows slightly higher energy efficiency than the passenger car used for city trips. The emissions of NOx and particles from the city bus are three times as high as those from the passenger car. The touring bus has the highest energy efficiency, followed by electric rail transport. (2) As mentioned above, a comparison of energy use with emissions per passenger kilometre using different passenger transport modes does not say anything about the effect on energy use and emissions of a modal shift from passenger cars towards public transport. Every increase in city-bus use at the cost of passenger-car use leads, at the current occupation rates, to avoiding an emission and energy use as large as the emission and energy use of one passenger car. (3) As a result of a further tightening of emission standards for road traffic combined with the delay of emission standards for diesel passenger trains, the environmental lead of electric passenger transport is declining. (4) With the current differences in type of transported goods, freight transport by road vehicles is 2 to 2.5 times less energy efficient than inland shipping or rail transport. However, the same can be concluded where transport of similar goods (containers) by the different modes is concerned. The emissions from electric rail transport are much lower than those from inland shipping or road transport. (5) In view of the coming tightening of the emission standards for road vehicles, combined with the delay of emission standards for freight trains (with diesel engines) and inland ships, there will be a much smaller gap between road and rail-freight transport in 2010.
Probabilistic Safety Assessment, (PROSA). Stochastic modelling of transport of radionuclides in the geosphere related to radioactive waste disposal in salt domesRheenen W van; Uffink GJM (1993-06-30)PROSA is a study on the safety of radioactive waste disposal in a salt formation using probabilistic techniques. The present report describes the determination of the input parameters for the PROSA calculations as far as the groundwater compartment is concerned. One of the most important parameters for the transport of radionuclides through the geosphere is the vertical groundwater velocity. This constant uniform velocity is interpreted as an effective velocity representing a 2-dimensional flow in a more complex geological system. This system is modelled with the code METROPOL using a Monte Carlo approach. Sets of input data are obtained by Latin Hypercube sampling. Particle tracking in the calculated flow field yields a travel time for conservative nuclides. The effective velocity is found by dividing the overburden thickness by the travel time. For the diapirism/subrosion scenorio the effect of a gradually decreasing thickness has been taken into account. Statistical analysis of the results indicates that the particle velocities are lognormally distributed. The data display a significant relationship between the particle velocity and the thickness of the overburden.