Air Dispersion Modelling Saudi Arabia: Input Guide

This air dispersion modelling inputs checklist lists what a project team needs to prepare for a permit, EIA, design or diagnostic study, and Saudi Environmental Studies coordinates the work in Saudi Arabia. We scope the inputs and coordinate the study, and the licensed consultant and modeller named in your proposal deliver, check and sign off the formal modelling.

You receive a written proposal setting out the scope, delivery parties and responsibilities, deliverables and price. Request a quotation

Air dispersion modelling does not begin with software. It begins with a defined decision and a controlled set of source, site, weather and receptor data. Weak inputs can produce precise-looking contours that do not represent the project. Early preparation helps the modeller identify gaps, agree assumptions and avoid repeated requests during a permit, EIA, design or diagnostic study.

Requirements vary by project and competent authority in Saudi Arabia. The responsible consultant must confirm the applicable model, guidance, averaging periods, scenarios and submission format before calculations begin. This article is preparation guidance, not a model protocol or legal interpretation, and a model does not replace the permit, approved method or regulatory decision that applies to your project.

Inputs for an air dispersion modelling study in Saudi Arabia

Start with the decision and study boundary

State why the model is needed: permit support, EIA/ESIA, design option comparison, cumulative assessment, incident review or internal planning. Identify the pollutants, sources, project phases, assessment area, receptors and operating scenarios. A model for routine operation may need a different basis from construction, startup, upset or future expansion.

Agree the authority and technical criteria that govern the study. Record the required averaging periods, background treatment, significance or comparison criteria and whether existing neighbouring sources must be included. Do not assume a US, European or vendor-default model is automatically acceptable for a Saudi submission.

The air dispersion modelling service is the formal study route. Delivery, checking and sign-off remain with the confirmed modelling consultant.

Air dispersion modelling inputs checklist: build a complete source inventory

List every relevant point, area, volume or line-like source and assign a stable identifier:

Stacks and vents: coordinates, elevation, height, diameter, exit temperature, velocity or flow, pollutant emission rate and operating schedule.
Area and fugitive sources: dimensions, release height, spatial distribution, activity and the method used to estimate emissions.

Document units, reference conditions, wet or dry basis and temporal basis. Identify whether rates come from stack testing, continuous monitors, mass balance, engineering calculation, emission factors or design guarantees. Include source dates, quality status and uncertainty. Maximum permitted, design and representative actual rates should not be mixed without explanation.

Describe operating cases such as normal load, partial load, maintenance, standby equipment and simultaneous operations. The modeller decides which combinations are technically and regulatorily appropriate. Missing sources are logged as gaps, not silently replaced with convenient assumptions.

Provide buildings, terrain and land-use information

Nearby structures can affect plume behaviour, so provide building footprints, heights and source relationships in a suitable coordinate system. Include tanks, warehouses, process structures or other obstacles where the selected model requires them. Confirm whether drawings represent existing, construction or future conditions.

Terrain and elevation data should cover sources, receptors and the model domain at a resolution suitable for the study. Land-use and surface characteristics may affect meteorological processing. The modeller specifies acceptable datasets and preprocessing; screenshots and unreferenced CAD extracts are not sufficient substitutes for controlled spatial data.

The GIS, sensitive-receptor and environmental constraints mapping service can coordinate spatial inputs and receptor registers.

Prepare representative meteorology

Meteorology may include wind speed and direction, temperature, cloud or radiation-related variables, pressure and parameters used to describe atmospheric turbulence. The exact inputs depend on the model and processing method. Provide the station location, height, instrument details, period, completeness, quality checks and relationship to the project site.

Onsite monitoring can add value when regional data are not representative, but it must be planned to the modeller’s requirements before collection. A weather station supplied for operations is not automatically suitable for a formal model. Missing periods, calm conditions, time zones and coordinate references require documented treatment.

Define receptors, background and scenarios

Build a receptor inventory that includes the project boundary, residential areas, schools, healthcare sites, worker or public locations, ecological receptors and other authority-required points. State coordinates, elevations and source of each dataset. Use sufficient grid resolution near areas where gradients may change rapidly.

Background concentrations should come from a justified source, period and method. Confirm whether the model requires measured background, authority data, conservative values or another approved approach. Avoid double counting sources already represented explicitly.

Create a scenario register linking emissions, source configuration, meteorology, controls and project phase. Name each scenario so reviewers can trace inputs to outputs. Version-control the final model input package and preserve calculation workbooks, test reports and correspondence.

What the modeller should deliver

Request an input register, assumptions and gap log, model/version statement, preprocessing records, quality checks, receptor maps, scenario results, source contributions, sensitivity work where required and editable input/output archives. Figures should state pollutant, averaging period, units, scenario and receptor basis.

US EPA’s AERMOD documentation illustrates why a formal modelling system includes meteorological and terrain preprocessors, current versions and application guidance. It is a technical reference, not a decision that AERMOD is the required model for this project.

How we work with qualified partners explains the responsibility boundary: Saudi Environmental Studies coordinates scope and inputs, and the licensed consultant delivers the formal modelling. Our coordination is available for projects across Saudi Arabia, including Jubail, Yanbu, Dammam and Riyadh.

Frequently asked questions

Who provides air dispersion modelling in Saudi Arabia?

Saudi Environmental Studies provides scoping and coordination of air dispersion modelling, and the licensed modelling consultant named in your proposal delivers the formal study.

What source data are usually needed for a stack?

Typical inputs include coordinates, elevation, height, diameter, exit temperature, velocity or flow, pollutant emission rate, units and operating schedule. The modeller should confirm the exact basis.

Can emission factors be used instead of stack tests?

Possibly, depending on the study and authority requirements. Record the factor source, activity data, calculation and uncertainty; do not mix estimated and measured rates without clear labels.

Is onsite weather monitoring always required?

No. The modeller determines whether existing data are representative and acceptable. If onsite data are needed, the siting, parameters, height, duration and QA/QC should be agreed before deployment.

What affects the cost of an air dispersion modelling study?

Cost depends on the number of sources and scenarios, the pollutants and averaging periods, the size of the model domain, meteorological data needs and sensitivity work required. The proposal sets out scope and price.

How long does an air dispersion modelling study take?

Duration depends on how complete the source, building, terrain and meteorological data are, the number of scenarios and the review cycles required. Gaps in inputs are the most common cause of repeated requests.

How do I use an air dispersion modelling inputs checklist for my project?

Define the decision and study boundary, build the source inventory, collect building, terrain and meteorological data, and agree receptors, background and scenarios with the modeller. The modeller justifies the model and version against authority guidance, and the authority decides acceptance; no consultant can guarantee permit approval.

To work through your air dispersion modelling inputs checklist with a specialist, Request a quotation and we will scope the study with you.

Saudi Environmental Studies serves projects across Saudi Arabia, including Dammam, Al Khobar, Jubail, Riyadh, Jeddah, NEOM and Qiddiya.