Noise mapping is a term that you’ll constantly hear about. Maybe you’ve heard about it at some point but still wondering why it’s essential in the first place. Well, a noise map is merely a map of an area which is colored as per the noise levels in the areas. At times, the noise levels may be shown by contour lines which display the boundaries between different noise levels in the area.
Bear in mind the noise levels over an area will always be varying. For instance, noise levels may increase as a car approaches, and reduce again once it drives away. This leads to a short-term variations in noise level. In the slightly longer term, noise level may be higher in peak periods when the roads are busy, and lower in off-peak periods.
What this simply means is that it’s not possible to say with confidence what the noise level will be at any given point at any instant time. But where the noise sources are perfectly defined, such as rail traffic or road traffic, then it is easy to say with some level of confidence what the long-term average noise level will be.
Some people tend to think that the ideal way to determine the long-term average noise in an area is by measurement. But experience shows that this is not really the case. For a start, a long-term average should be measured over a long haul. And to obtain complete coverage of an area, you would have to make measurements on private property, where access might be difficult.
Moreover, measurements can’t distinguish the different sources of noise. For this reason, they would not be able to offer information on how much noise was being made by each of the sources in an area. No wonder noise mapping is mostly done by calculation based on a computerized noise model of an area. Although measurements might sometimes be appropriate.
The good thing about counting on noise mapping is that it can be leveraged to assess the effects of transportation and other plans. Thus, the effect of a proposed new road can be assessed and suitable noise mitigation can be perfectly designed to minimize its impact.
This always proves beneficial in noise action planning, where a cost-benefit analysis of various options can be tested before a decision is finally made.
