Oliveira, Ronaldo Pereira de 
2.1.5 GIS Procedures: To accomplish the execution of main project phases, the ILWIS 2.1 (Integrated Land and 
Water Information System, 1997) environment was used in order to organise geometric attributes from thematic terrain 
objects. In this way, providing means to process basic spatial analysis as: statistical histograms, cumulative area 
calculation, two dimensional table definition for thematic overlays, and attribute tables for either correlation, class 
generalisation, or topology generalisation. For this purpose, most of basic digital information was supplied by SMAC: 
1 - the topographic base map, georeferenced at 1:50,000 scale, in order to supply a common geometric data structure to 
both institutions; 2 - satellite images SPOT XS + PAN composition, scenes K722/J395 and K723/J395; 3 - the land use 
and vegetation coverage map (SMAC-RJ, 1997) in vector structure, at 1:50,000 scale, which was converted from raster 
format output of previously executed supervised classification; and 4 - remote sensed coverage information, on paper, 
of aerial photographs and SPOT satellite images for photo interpretation procedures. 
After to import “dxf ” formatted files, the database structure organisation started with class domain analysis of the 
derived products, thus a revised soil map at 1:75,000 scale; a land suitability map; a land vulnerability map; and a land 
environmental quality map. The existing soil map of the of Rio de Janeiro district (Embrapa, 1980), at 1:50,000 scale, 
was georeferenced using the imported base map from SMAC. Further procedures involved the adjustment of vectored 
land cover information, which was extracted from digital image supervised classification in order to update urban 
expansion and specific vegetation with relevant biological concern. More over, the printout of the existing soi] map 
served as basic material to fieldwork excursions. After the field data collection, laboratorial analysis and legend revision 
routines, new delineation of map units were digitised, as well as the point map for soil class identification. The final 
procedure of polygon generation requested some extra time for proper understanding of map domain definitions in 
ILWIS environment. 
2.2 Integrated Geoinformation Modelling 
The use of ILWIS 2.1, under an object-oriented approach, has required some substantial changes on previous 
operational processes and concepts for survey and mapping activities. The specific objective of this study was to 
evaluate suitable changes in traditional soil survey methods using elementary concepts of object-oriented methodology 
to execute conceptual system and data structure modelling. This choice aimed to facilitate information exchange, 
communication, by use case diagrams reflecting thematic abstractions, representations, and notations, according to 
UML analysis and design models (Rational, 1997). In addition, it was expected that this technology would be able to 
handle complex requirements of thematic integration. Furthermore, there is still necessary to show some surveyors the 
potential use of geographical analysis, because they usually can only see the automated cartography aspect of GIS. 
Therefore, they are still thinking in a manual process basis. For this reason, the idea was that the survey team should 
participate during modelling activities for both better guidance of thematic abstractions, and understanding of process 
driven models that can open new perspectives of spatial reasoning for land evaluation and zoning. Keeping away the 
perspective of pure technology just executing statistical analysis, automated functions, and geometric calculations. 
Concepts for terrain objects modelling and formal data structure (FDS) in GIS environment are based on Molenaar 
(1996). In this sense, the conceptual model for environmental planning should also represent a multi-scale framework 
with different aggregation levels of information, besides to require inheritance, polymorphism, association, and 
generalisation constructs to be considered. Therefore, the integrated geoinformatiom model considered object classes 
and relationships from detailed field information up to district planing level. Still, SMAC has also contracted the 
previous described methodology to be applied in pilot watersheds at 1:20,000 scale. Consequently, the soil survey was 
done to generate more detailed planning information of critical areas around hillside slums (Embrapa, 1999b). Land 
suitability, land vulnerability, and land environmental quality were further generated in digital form, but still under 
traditional survey procedures. During the execution of SMAC projects, there was no concern to promote analysis 
considering distinct levels of information, appearing to have different survey purposes for two completely different 
areas. For this reason, the integrated model includes abstractions on how terrain object classes are related to terrain 
object superclasses. In final, the model predicts that future surveys at watershed level could be oriented by 
specialisation of upper level information, as they are already available at 1:75,000 aggregation level. 
3. RESULTS 
3.1 Environmental Planning Information 
Project products for both survey levels were submitted to SMAC, having the quantitative information presented in 
Embrapa (1999a, 1999b), and the complementary GIS database. The soil survey could classify 41 different soil types 
and 7 special terrain types. One point to be observed is the difference of the total district area calculated in GIS, it 
shows a total area of 122,031.7 ha, against the official area of 125,250 ha given by the municipality statistical book. 
  
  
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000. 1077