IMMI covers a wide range of applications ranging from noise mapping to air pollution modelling. IMMI integrates both noise and air pollution in a single software package. In this section we will concentrate on the features of IMMI specifically designed for air pollution mapping and dispersion modelling. With its modular design and price-list, IMMI can be tailored to the user's needs and budgets - ask for details.

IMMI is continuously adapted to meet the requirements of evolving regulations and standards. Currently IMMI can be equipped with

• air pollution dispersion calculation methods for industrial and road traffic sources
• Gaussian and Langrangian air pollution dispersion models from Germany and Austria

Regional air pollution mapping gained additional importance with the arrival of EU's 1996 Air Framework Directive and the subsequent pollutant-specific Daughter Directives. Modelling is an assessment technique specifically referenced in the Daughter Directives. IMMI contains algorithms that can be used for small-, medium- and large-scale mapping and is thus suitable for everything from assessment of the pollution in the vicinity of polluting sources up to regional air-pollution modelling of the Daughter Directives.

I. General-purpose Gaussian model

IMMI– the universal environmental pollution software – features a fully operational Gauss model in its base module. The model is based on the proven German TA-Luft, Annex C of 1986.

• Dispersion calculation for gaseous and odorous pollutants and dust.
• Point, line and area sources.
• Effective source height for cold and warm exhaust gases.
• Odours: Percentage of hours of a year with odour perception.
• Calculation of receptor grids or single user-defined receivers.
• Calculation of odour streams for livestock.
• Calculation of road traffic emissions from traffic density data and associated emission factors (e.g. COPERT).

For further information see Log-In area.

II. Langrangian air dispersion model

The Lagrangian model follows the pathways of a sub-set of individual particles in the atmosphere and determines a concentration or deposition at a given moment in time from the spatial distribution of the particles followed by extrapolation on the total population in the exhaust plume.

• Simultaneous calculation for up to 45 gaseous and particular pollutants.
• Point, line and area sources.
• IPPC: Ambient air quality directive
• Gases: Calculation of fields of concentration for the assessment periods year, day, hour (pollutant-dependent)
• Dust particles: Calculation of both sedimentation and deposition for the assessment periods year, day, hour (pollutant-dependent).
• Wind-field calculation takes into account variations in terrain level.
• Calculations use statistical meteorological data (wind speed, wind direction and stability classes).

For further information see Log-In area.