Air Dispersion Modelling

Numthaja Environmental Consulting provides Air Dispersion Modelling services for projects and facilities that need to understand how air pollutants spread within the surrounding environment, assess the expected impact zone, and support technical decisions related to operation, compliance, and emission reduction measures.

This service helps analyze the movement and dispersion of pollutants emitted from different sources, linking the results to project characteristics, meteorological conditions, site context, and nearby sensitive receptors in support of environmental assessment and high-quality technical deliverables.

What is Air Dispersion Modelling?

Air dispersion modelling is a technical process used to analyze how pollutants move and disperse in the atmosphere based on source characteristics, meteorological conditions, site context, terrain, and relevant operational factors. It helps estimate expected concentrations, identify potential impact zones, and compare results against relevant environmental standards.

When does a facility need Air Dispersion Modelling?

When the project or facility has air emissions
When environmental studies require air quality assessment
When comparing results against relevant environmental standards
When studying operational alternatives or source configurations
When evaluating the need for emission reduction measures
When sensitive receptors are located near the site

What does the service include?

1. Understanding the project and emission sources

Reviewing the type of activity and key emission sources
Understanding baseline and alternative operational conditions
Identifying nearby sensitive elements
Defining the objective of the modelling and the required scope of analysis

2. Preparing technical inputs

Organizing source and emission data
Preparing relevant meteorological and spatial data
Setting up the required scenarios for analysis
Linking the study to the nature of the project and the site

3. Running the modelling and analysis

Analyzing pollutant dispersion under the required scenarios
Preparing maps and graphical outputs
Comparing different scenarios when needed
Understanding how certain technical or operational variables affect the results

4. Interpreting the results in relation to the project

Reading expected concentrations around the project
Identifying the most affected areas
Supporting operation or mitigation-related decisions
Linking the results to final environmental studies and deliverables

What can Air Dispersion Modelling support?

Assessment of the expected pollutant dispersion range
Understanding the influence of meteorological conditions and wind patterns
Comparison of different operational scenarios
Evaluation of technical alternatives such as source characteristics or stack height
Support for mitigation measures and emission reduction planning
Technical and graphical outputs that support environmental decisions

Examples of technical outputs

In one of the company’s applications for a project located on the western coast of Saudi Arabia, air dispersion modelling showed how certain detailed technical variables can directly influence the dispersion pattern and resulting concentrations, including source characteristics, stack height, assessment grid configuration, and the relative location of surrounding elements.

Study area map for an air dispersion modelling project — Illustrative example of the study area and spatial elements used in an air dispersion modelling project.

Assessment grid and surrounding elements in an air dispersion model — Example showing the assessment grid and some surrounding elements influencing interpretation of modelling results.

The following examples also illustrate model outputs for different pollutants under different time periods and operating scenarios, supporting interpretation of the expected impact zone and linking the results to the project’s environmental context.

PM10 one-hour concentration map — Example of a modelling output showing the spatial distribution of PM10 concentrations over a one-hour period.

SO2 24-hour concentration map — Example of a modelling output showing the spatial distribution of SO2 concentrations over 24 hours.

The following two images demonstrate how changing stack height alone, while keeping the main assumptions otherwise consistent, can lead to a clear difference in the dispersion pattern and expected results. This is an important example of how detailed technical parameters can affect interpretation and decision-making.

PM10 modelling result for one stack height scenario — Model output showing the spatial distribution of PM10 concentrations for one stack height scenario.

PM10 modelling result for a different stack height scenario — A second model output showing how a different stack height can influence the dispersion pattern and expected concentrations.

Sectors that can benefit from the service

Industrial facilities
Desalination and power plants
Factories and production lines
Crushers and quarries
Service and development projects
Projects with stationary or mobile emission sources

Why Numthaja?

Experience in linking air dispersion modelling with environmental studies and compliance requirements
Ability to interpret results within the context of the project and surrounding environment
Clear analytical and graphical outputs that support technical decisions
Strong understanding of how detailed technical variables influence model results

How do we start?

Share project information and emission source details
Define the modelling objective and required scope of analysis
Review available meteorological and technical data
Start the work and prepare the appropriate deliverables
Deliver the results and link them to the related environmental study or report

Request the service

If you need Air Dispersion Modelling services, you can contact Numthaja Environmental Consulting to begin reviewing your project and defining the appropriate scope of work.