| A wide range of data collected by monitoring systems and by mathematical and
physical modelling can be managed in the frame of spatial models developed in
GIS. In addition to data management and standard environmental analysis of
air pollution, data from remote sensing (aerial and satellite images) can
ehance all data sets. In spite of the fact that simulation of air pollutant
distribution is carried out by standalone computer systems, the spatial
database in the framework of the GIS is used to support decision-making
processes in a more efficient way. Mostly, data are included in the map
layers as attributes. Other map layers are carried out by the methods of
spatial interpolation, raster algebra, and case oriented analysis. A series
of extensions is built into the GIS to adapt its functionality. As examples,
the spatial models of a flat urban area and a street canyon with extensive
traffic polluted with NOx are constructed. Different scales of the
spatial models require variable methods of construction, data management, and
spatial data sources. The measurement of NOx and O3 by an
automatic monitoring system and data from the differential absorption LIDAR
are used for investigation of air pollution. Spatial data contain digital
maps of both areas, complemented by digital elevation models. Environmental
analyses represent spatial interpolations of air pollution that are displayed
in horizontal and vertical planes. Case oriented analyses are mostly focused
on risk assessment methods. Finally, the LIDAR monitoring results and the
results obtained by modelling and spatial analyses are discussed in the
context of environmental management of the urban areas. The spatial models
and their extensions are developed in the framework of the ESRI's ArcGIS and
ArcView programming tools. Aerial and satellite images preprocessed by the
ERDAS Imagine represent areas of Prague. |