software maintenance

Conflict Maps and more

Creating normal Grid Noise Maps consists of defining the calculation area, calculating the noise map, and displaying the noise levels in the Graphics. However, there is often a demand for answers that go beyond what can be seen in the simple display of noise contours. It is common for a client to request a noise map depicting conflicts with the noise ordinances. Such a map would show how many dB it is louder than the maximum noise levels allowed for each area.

SoundPLAN's configuration allows the user to amend and correct a number of noise assessments, or even define noise assessments of his own. After defining the time slot and duration, and the beginning and end time, define the noise limits for the zoning as foreseen in the guideline. In the above example from Germany, there are noise limits for the morning, day, evening and night for different zoning ranging from industrial, to residential, to hospitals. In some standards, such as the L_den for the EU, penalties can be superimposed on certain times and zoning definitions.

After the assessment information is defined, SoundPLAN can generate a contour map showing where noise limits are exceeded. Select the cut-off number for mapping the conflicts. Our example used 5dB less than the limit.

In the following picture, the conflicts are mapped zone by zone. When zones have different noise limits, the contour lines (colors) may not match.

SoundPLAN's noise evaluation modules contain additional features needed for EU noise mapping. For EU noise mapping, the main point is not to map conflicts, but rather to evaluate and depict how many people are subject to excessive noise levels in their residences. The focus is on evaluating how many residents in all the buildings in an area are exposed to noise. Along with keeping statistics of the noise exposure, the Noise Mapping Evaluation is also able to map the problems of exposure. As there are no standards yet concerning how to depict the exposure, SoundPLAN offers several solutions that the user can customize (i.e. mapping absolute numbers or density of exposure).

Details of the of the assessment of the noise exposure can be seen in the description of the Spreadsheet. Aside from the macro capabilities, the program can automatically tally the values of the number of square meters of buildings or the facade length, and thus distribute the number of residents for each building floor, and evaluate how many residents are subjected to which noise level. If the total number is divided by the size of the area, the density of exposure can be generated. For big cities, the density of noise exposure is probably the best presentation.

Last modification: 14 January 2004