- Understanding aviation noise
- Noise mapping
- ANIMA Virtual Community Tool
Below, several scenarios are demonstrating the capabilities of the demo Virtual Community Tool. Showing differences in contour sizes is definitely not for giving a position on what is appropriate to use – it is just for showcasing purposes.
- 1. Multi-metrics evaluations
- 2. Sleep-time preference
- 3. Scenarios to expect
- 4. Future
- 5. Critical hours
- 6. Land-use planning
State-of-the-art research suggests the definition of protection zones based on several properties, not just one. For aircraft noise, WHO recommends limiting the aircraft noise exposure to less than 45 dB Lden, and for Lnight 40 dB. Another recommendation is to keep the average additional awakenings induced by the noise below 1 per night (Basner, M.,2008). As a demo, VCT is capable of computing and showing several metrics at the same time, one can observe what areas should be protected to fulfil all three conditions (Figure 1).
People differ from each other. Some prefer to go to bed later and also get up later, others go to sleep earlier and get up earlier. With the ability to flexibly change the sleeping hours of people, independently from the night period defined in regulations by each country, with our tool, one can observe that “late sleepers” in a much larger area have their nights unprotected from being woken up more than once in average by the air traffic (Figure 2). This example shows that while it is not realistic to completely shift the “airport work start” to one hour later, it is an option to change at least some flights to after 7 o’clock, or in case there is a budget for it, to extend the window insulation programs to a larger area, or, finally, at least to spread the knowledge that “late-sleepers should not live near airports”.
Generally regular but non-preferred configurations could cause complaints because published maps often present only the long-term average, lowering less frequently happening noise events for areas that receive high noise load only during non-preferred times. The effect is even more substantial when preferred, and non-preferred configurations are considered. It is worth explaining to people by visualisation why sometimes they feel so bad about the noise: after a period with favourable conditions, the contrast to the unfavourable is much more visible. However, such scenarios are computed from completely different flight schedule lists. This is not a problem for the VCT, as the intelligent visualisation engine can present several scenarios on the same map (Figure 3).
During the land-use planning, it is wise to look towards the future. While nobody can tell what will actually happen, most airports already have experience evaluating their flight traffic over the years. Most probably, the increase in flight operations and the renewal of airlines’ fleets can be estimated. To compute such expectations is easy for the VCT user: just the increase in the total number of flights need to be changed, and a few replacements of some older, but frequently used aircraft types by some current ones and afterwards, one can have an idea how the airport’s footprint will perhaps evolve in the upcoming years. Figure 4 depicts such estimation.
We know from experience that some hours are more critical than others, e.g. falling asleep is more prone to disturbance by noise events than when one is already asleep. Therefore, people could be interested in aircraft traffic during these hours. As VCT performs internal computations on an hourly basis, the Map Display Window allows the presentation of metrics for specific hours over the map and overlays contours for several hours (Figure 5).
Land-use planning is a powerful way to control noise annoyance. Building well-soundproofed business areas or shopping centres near airports could be examples of it. In these areas, there will be no people disturbed during the night-time, and, during the day, business areas can afford to pay for well-soundproofed buildings, while in shopping centres the noise levels are usually already so high indoors that higher outside noise levels are not relevant. Also, the effect of financing window insulation in a certain area is worth studying, especially if we know the typical original sound insulation quality of houses and the seasonal habit of people to close or leave their windows open during the nights. The VCT allows for an easy definition of land-use planned areas by defining simply their functionality. Moreover, a map containing the typical sound insulation quality of houses around the airport can be used by the tool, so soundproofing improvement can be easily studied. Figure 6 shows an example: some buildings in the area received window insulation, and a business centre has been established near the airport.