Geoscience Reference
In-Depth Information
6.3. LAURE and territory age
For a long time now information used in the field of atmospheric pollution has
been focused on the evolution of levels over time for both administrative and health
reasons. Conversely, spatial information has become increasingly used because
modeling techniques have improved the quality and reliability of the spatial
information available.
European directives predict that modeling will be increasingly used as a
technique to measure air quality. It will be used alongside the measurements
recorded by the measurement networks. The aim of this approach is to examine the
level of atmospheric pollutants present in the atmosphere on a global surrounding,
even in regions that have low levels of pollution and do not require an analyzer to
continuously check whether pollutants are present in the atmosphere. Frameworks
drawn up for monitoring air quality describe the different methods used to monitor
air quality for a particular country. The law passed on March 17, 2003, concerning
the monitoring of air quality as well as the provision of information to the general
public, enables each AASQA to evaluate its own monitoring equipment, and to
adjust it for any changes that occur in air quality. The equipment can be adjusted
thanks to the introduction of an air quality monitoring program (PSQA). In areas
that have high levels of pollution or in areas where it is likely that the maximum
pollution thresholds (set by the European Commission) will be exceeded, the air is
continuously monitored by using sensors and analyzers located at fixed measuring
sites. Whenever the pollution level is situated between the maximum and minimum
threshold levels, air quality monitoring is carried out by a series of measurement
campaigns and modeling. Whenever pollution levels are lower than the minimum
threshold level then modeling can be used. Specific studies can be carried out for
certain measurement sites, such as those close to large industries or to areas in
which there is a lot of traffic.
Nowadays, however, preventing atmospheric pollution does not only involve
monitoring air quality, as was the case during the period of heavy industrial
pollution. Currently, to prevent atmospheric pollution it is necessary to examine
how different sources are managed; these sources include transport, housing, and
agriculture, etc. It is possible to use a GIS to respond to these issues as the GIS is
capable of linking air quality with other geocoded factors that can be used in three
ways: first of all the GIS can be used to identify ways in which atmospheric
pollution can be prevented on a local level. It can also be used to evaluate the
benefits of projects undertaken monitoring the decrease in pollution levels. Finally,
it can be used to examine the health risks created by exposure to the pollutants. This
final method is possible by identifying those members of the population who have
been exposed the most to the different pollutants present in the atmosphere.
These complex information systems, however, rely on a paradox. There tend to
be less spatial variations of atmospheric pollution than variations of atmospheric
pollution measured over time. This is due to the influence that meteorological
factors have on the concentration of the pollutants present in the atmosphere and on
