ADMS 6 - Industrial Air Pollution Modelling Software

The dispersion model ADMS 6 is currently used in many countries worldwide. Users of ADMS 6 include:

• over 130 individual company licence holders in the United Kingdom,
• regulatory authorities including the UK Health and Safety Executive (HSE),
• Environment Agency in England,
• Scottish Environmental Protection Agency (SEPA) in Scotland,
• Northern Ireland Environment Agency (NIEA) in Northern Ireland,
• Natural Resources Wales,
• government organisations including the Food Standards Agency (United Kingdom),
• users across Europe, Asia, Australia, North America, Africa and the Middle East.

ADMS 6 is a new generation Gaussian plume air dispersion model, which means that the atmospheric boundary layer properties are characterised by two parameters:

• the boundary layer depth, and
• the Monin-Obukhov length

rather than in terms of the single parameter Pasquill-Gifford class.

Dispersion under convective meteorological conditions uses a skewed Gaussian concentration distribution (shown by validation studies to be a better representation than a symmetrical Gaussian expression).

Model options: ADMS 6 has a number of model options including: dry and wet deposition; NO_x chemistry; impacts of hills, variable roughness, buildings and coastlines; puffs; fluctuations; odours; radioactivity decay (and γ-ray dose); condensed plume visibility; time varying sources and inclusion of background concentrations.

Meteorological pre-processor: ADMS 6 has an in-built meteorological pre-processor that allows flexible input meteorological data both standard and more specialist. Hourly sequential and statistical data can be processed, and all input and output meteorological variables are written to a file after processing.

User-defined outputs: The user defines the pollutant, averaging time (which may be an annual average or a shorter period), which percentiles and exceedence values to calculate, whether a rolling average is required or not and the output units. The output options are designed to be flexible to cater for the variety of air quality limits, which can vary from country to country, and are subject to revision.

Visualisation: ADMS 6 includes the Mapper: an integrated mapping tool for displaying and editing source data, buildings and receptor locations and viewing results. The model has links to the Surfer contour-plotting package, in addition to ArcGIS and MapInfo Professional Geographical Information System (GIS) software. The GIS links can be used to enter and display input data, and display output, usually as colour contour plots.

Terrain converter: Utilities are available for creating terrain files from commonly available data formats such as SRTM and OS Terrain 50.

Emissions Sources

ADMS 6 can be used to assess the effect of emissions from a number of industrial source types:

• Point source e.g. emissions from a stack or vent.
• Area source e.g. evaporative emissions from a tank.
• Line source e.g.emissions from a conveyor belt at a quarry.
• Volume source e.g. fugitive emissions.
• Jet source (directional releases) e.g. emissions from a ruptured pipe.

The maximum number of sources that can be modelled in ADMS 6 is 300. Of these up to 300 may be point or jet sources, and within the limit of 300 up to 30 line sources, 30 area sources and 30 volume sources may be modelled simultaneously.

ADMS 6 uses a built-in mapper for helping to manipulate the emissions data (see the Visualisation tools page for more information).

Meteorological Data

Meteorological data is available in ADMS format from a number of suppliers. The advanced ADMS meteorological pre-processor determines the structure of the atmospheric boundary layer based on the input data. Hourly sequential or statistical meteorological data may be input.

Background Concentrations

Hourly sequential or averaged concentrations of background pollutants may be included if required.

ADMS can give output for up to 25 pollutants in one run, which may be either long-term statistical output or short-term output for each hour or meteorological condition in the input meteorological data. Rolling averages, exceedences and percentile statistics may also be calculated.

Output is given on a grid of receptor points covering a specified area and/or at specific receptor locations. Gridded results can be contoured using the ADMS Mapper or one of the included links: Surfer, ArcGIS or MapInfo (see the Visualisation tools page for more information).

Where only a single point source is modelled, ADMS 6 produces output containing detailed plume characteristics, such as plume centreline concentration, plume height, plume spread, etc., which can be graphed using the included ADMS Line Plotter.

Where hills are modelled, there is an option to output the FLOWSTAR flow field, which can be contoured using the included ADMS Vector Plotter.

Other individual model options produce specific model outputs; for full details see the model documentation.

The ADMS 6 model was developed by CERC, with some of the model options written in collaboration with other research organisations, such as the UK Meteorological Office, University of Surrey, and National Power (now part of E.ON). The model has been comprehensively verified. A number of verification papers are available for download from the Model validation page.

ADMS 6 is supplied with an in-depth user guide (see the User guides page) that details all user inputs and outputs, and includes a number of step-by-step worked examples.

Full details of the technical specification of ADMS 6 can either be found in the Technical specifications page or on request from CERC.

An annual maintenance contract provides support for users; this includes:

• maintenance model upgrades,
• use of the helpdesk by e-mail, phone, fax or post,
• attendance at the annual user group meetings,
• newsletter twice a year, and
• access to the password-protected user area.

The model interface is designed so that the user can enter the data required for the modelling in as straightforward a way as possible.

The interface consists of several main screens. To set up a model run, the user simply works through the screens entering the relevant data or referencing external data files.

ADMS Model Feature Comparison Tables