Frequently Asked Questions
Below is a sample list of questions that may assist you.
- What noise mapping has been undertaken?
- What is an agglomeration?
- What airports have been noise mapped?
- How do the noise maps compare to previous airport noise contours?
- What industry has been noise mapped?
- Does this site include noise maps for the whole of the UK?
- Do noise maps show how noisy it is where I live?
- How is Population Exposure calculated?
- What are consolidated noise maps?
- What about quiet areas?
- Why prepare action plans?
- What will action plans contain?
- Where can I find more information about the Noise Mapping NI project?
- What is noise?
- What is a noise map?
- What are the noise maps for?
- How were the noise maps produced?
- What is the currency of the noise maps?
- How accurate are the maps?
- Who has produced the noise maps?
- Which Browsers are supported by this website?
- Where can I find information on Neighbourhood Noise or other related matters?
What noise mapping has been undertaken?
As required by the Environmental Noise Directive, in this first round maps have been produced for major roads which have more than six million vehicle passages per year, major railways which have more than 60,000 train passages per year, major airports with more than 50,000 air traffic movements per year and transport sources and industry in agglomerations (see below for the definition of an agglomeration).
For the second round of mapping in 2012, in addition to re-mapping the areas covered in the first round, roads having more than 3 million vehicle passages per year and railways with more than 30,000 train passages per year are to be mapped. All agglomerations with a population of over 100,000 will also be mapped. The actual roads, railways and agglomerations to be mapped will be subject to confirmation based on the most up to date data available at the time.
An agglomeration for the purposes of this round of mapping is a urban area with more than 250,000 inhabitants. The only agglomeration that meets this criteria in Northern Ireland is the Belfast Metropolitan Urban Area.
What airports have been noise mapped?
In accordance with the Environmental Noise Regulations (Northern Ireland) 2006, Belfast International Airport is classified as a ‘major airport’. In other words, it had greater than 50,000 air traffic movements during 2006. As such, it has been included in the noise mapping project.
George Best Belfast City Airport is not classified as a ‘major airport’, but has been included as a relevant noise source located within the agglomeration of Belfast.
How do the noise maps compare to previous airport noise contours?
Prior to the implementation of the Regulations, some airports had previously produced noise contours. These, however, tended to represent the situation on an average summer’s day between 16th June and 15th September and presented the noise levels in terms of the LAeq,16h indicator.
The noise maps published here, however, are for an average day over the whole year, in this case 2006. Thus there is likely to be a difference between the results for an average day in the summer period (which for most airports is the busiest) and an average day in a year.
It has also been found that the Lden indicator tends to produce larger contours than the corresponding LAeq,16h indicator. This is because the noise which occurs in the evening (1900 – 2300) and at night (2300 – 0700) attracts an artificial weighting of 5dB and 10 dB added respectively before being combined to produce the Lden.
It is not yet known whether or not the Lden provides a better representation of the noise from airports.
What industry has been noise mapped?
In accordance with the Environmental Noise Regulations (Northern Ireland) 2006 industrial noise means:
- Part A activities as defined in Schedule 1 of the Pollution Prevention and Control Regulations (Northern Ireland) 2003, within an agglomeration or first round agglomeration; and
- Ports within an agglomeration or first round agglomeration.
Does this site include noise maps for the whole of the UK?
This site includes maps for Northern Ireland only. To see maps for England, Wales and Scotland please visit the websites listed under Useful Information.
Do noise maps show how noisy it is where I live?
The noise maps are only intended to be used for strategic assessment of noise levels in any given area. They should not be used in an attempt to determine, represent or imply noise values at specific locations such as individual residences or buildings. It should also be borne in mind that the noise levels shown are for an average day in an annual period and, therefore, do not show the specific noise from individual vehicles, trains or aircraft.
How is Population Exposure calculated?
Population exposure figures are calculated by firstly adjudicating census data to buildings in the mapped area (not by actual number of people living inside a single dwelling within a communal building, for example, but by statistically spreading the number of people across all dwellings in the building). A count is then made of the number of people falling in each noise band calculated.
What are consolidated noise maps?
Consolidated maps show a calculation of the total noise level from all sources covered by the Environmental Noise Directive - road, rail, aircraft and industry - on a single noise map. Current research shows that consolidated maps are best produced as a simple logarithmic sum of the separate calculated noise levels for each source. This means that any decibel weightings, such as those for Levening and Lnight are applied only once, as is appropriate. Consolidated noise maps are only available for the Belfast agglomeration.
The noise maps are designed to provide a strategic overview of the noise impact from selected sources. What may be quiet for one source may not be so for another. Therefore, potentially quiet areas can only be assessed using the consolidated noise maps for all sources combined. Areas on the consolidated noise map (pdf only) for the Belfast agglomeration have been identified as candidate quiet areas and equate to those areas below the Lden 55dB and Lnight 50dB noise bands. These are the lower limits required for noise mapping by the Environmental Noise Directive.
The Department of the Environment is considering the options available to identify quiet areas as part of the action planning process.
It is a requirement of the Environmental Noise Directive that Member States produce action plans based on the results of the noise mapping. The Environmental Noise Regulations (Northern Ireland) 2006 subsequently require the competent authorities to prepare these action plans in 2008, 2013 and every five years thereafter.
What will action plans contain?
The competent authorities must prepare action plans based upon the noise mapping results, with a view to preventing and reducing environmental noise where necessary and particularly where exposure levels can induce harmful effects on human health and to preserving environmental noise quality where it is good.
Action plans must be designed to manage noise and its effects, including noise reduction if necessary. They must also aim to protect quiet areas in agglomerations against an increase in noise.
Action plans will contain an evaluation of the estimated numbers of people exposed to noise and include details of any noise reduction measures, or limit values already in place for the relevant sources. They will then identify any potential problems or situations that may need to be improved.
Where can I find more information about the Noise Mapping NI project?
Final reports on the production of noise maps for Northern Ireland can be viewed here.
The commonly accepted definition of noise is ‘sound which is undesired by the recipient’. In other words, noise can be any sound which is intrusive, disturbing or annoying. It is very subjective – what is noisy for one person may not bother someone else. Noise is measured in decibels on a logarithmic scale, such that a doubling of sound energy equates to a three decibel increase. The Glossary of Noise Terms gives examples of relative decibel levels of some common noise sources. The Department of the Environment has produced an information booklet which provides general advice on noise and noise related issues: Bothered by Noise? – there’s no need to suffer
A noise map is a map designed for the global assessment of noise exposure in a given area due to different noise sources or for overall predictions for such an area. Just as an Ordnance Survey map may have contours joining positions of equal height, a noise map illustrates contours that join points of equal noise level.
Noise maps have two main purposes. Firstly, they can be used to find areas where noise levels are high and these can be linked to population data to estimate how many people are affected. This leads to the second use – and the main reason for mapping noise – to inform the development of action plans for the purpose of managing noise exposure by reducing noise levels, or preserving quiet areas where appropriate.
How were the noise maps produced?
The noise maps presented here were produced by computer modelling techniques that calculate the noise level at specific points as the sound emanates from the particular sources. The modelling software utilised data such as traffic flow, type of road and rail, types of vehicles and the nature of industrial processes. Also considered were features that can directly affect sound, transmission, such as potential barriers, topography, weather conditions and how reflective or absorbent different surfaces can be. The calculations produced noise levels at receptor points on a 10 metre grid at a height of four metres above the ground.
The data required for the calculations was supplied by Environment and Heritage Service, Roads Service, Translink, Belfast International Airport, George Best Belfast City Airport, Port of Belfast and Ordnance Survey of Northern Ireland.
What is the currency of the noise maps?
The noise maps on this site represent environmental noise levels in Northern Ireland for an average day in the year 2006, as required by the Environmental Noise Directive and the Regulations.
The noise maps are produced for use at a strategic level and provide an acceptable level of accuracy for this purpose. They will not however represent every situation at a local level and it is likely that more detailed examination will be necessary in some of these situations in order to develop local action plans.
To ensure that the current noise calculations could be replicated, a series of verification calculations have been undertaken as part of the project. The resulting modelled noise levels have also been compared to levels measured at the Belfast Ambient Noise Monitoring Station.
Who has produced the noise maps?
A consortium of specialist contractors, led by iSoniq Ltd. was appointed via open competition in order to complete the project on behalf of the Department of the Environment, the Department for Regional Development, Northern Ireland Transport Holding Company, Belfast International Airport and George Best Belfast City Airport
Which Browsers are supported by this website?
The following browsers are supported by this website:
- Internet Explorer v6x
- Internet Explorer v7x
- Firefox v2x
Why do I need to enable JavaScript?
JavaScript is required to navigate the noise map and experience the optimum user experience from this site.
Why should I keep JavaScript disabled?
Some browsers are setup with JavaScript disabled by default (particularly under certain corporate security policies). This may prevent you from enabling JavaScript or could open up your computer to potentially harmful access. You do so at your own risk.
How can I enable JavaScript on my browser?
To enable JavaScript for your browser, please see the instructions below:
Internet Explorer v7x & v6x:
1.Go to the Tools menu and select Internet Options
2.In the Internet Options window, select the Security tab (at the top of the window)
3.Under the Security tab, select the Internet Web content zone
4.Under Security Level for this zone:
If there is a slider bar move the slider bar to Medium. Otherwise, if the security level is Custom:
- Click on the Custom Level button at the bottom of the page to open the Security Settings window
- In the Security Settings window scroll down until you get to the section called Scripting (near the bottom)
- Under Scripting there is a category Active scripting, select the option marked Enable for this category
- Click OK
To disable JavaScript:
- Click on the Custom Level button at the bottom of the page to open the Security Settings window
- In the Security Settings window scroll down until you get to the section called Scripting (near the bottom)
- Under Scripting there is a category Active scripting, select the option marked Disable for this category
- Click the OK button
Firefox v2x:
- Go to the Tools menu and select Options
- Select Content
- Check enable JavaScript setting
- Click OK