Information and Knowledge Management using ArcGIS ModelBuilder

Teresa Santos, Ségio Freire and José António Tenedório
surface is increasingly recognized as a key indicator for assessing the sustainability of land use
changes due to urban growth.
Figure 1: Study area and data set used for building Lisbon’s impervious surface map
Table 1: Land cover nomenclature
Level 1 Level 2
Vegetation Trees
Low vegetation
Impervious surface Buildings
Roads
Other impervious surfaces
Soil Soil
Shadow and Water Shadow and Water
Soil is vacant land and is usually comprised of soil with little vegetation, thin soil, sand or rocks.
Shadows occur in remotely sensed imagery when objects totally or partially occlude the direct light
from a source of illumination, which include cast shadows (shadows cast on the ground, or on other
objects, by high-rise objects), and self-shadows (the part of the object that is not illuminated)
(Salvador et al. 2001). Great difficulty arises in classification and interpretation of shaded objects in an
image due to the reduction or total loss of spectral information of those shaded objects (Dare 2005).
This issue is particularly significant in urban environments where tall buildings are often present.
Water is included in the same class as shadow, since both are dark objects in the image that will not
be used for producing urban indicators.
3.1 Pre-processing
Based on the original IKONOS-2 imagery, a pansharp image of the visible and panchromatic bands
was produced, using the method available at PCI Geomatica. This new pansharp image has a spatial
resolution of 1 m. The IKONOS-2 pansharp image was then orthorectified in order to reduce the
geometric distortions introduced by the relief and to attribute a national coordinate system (ETRS89).
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