Oliveira, Ronaldo Pereira de
process where the original data set could be revised or coupled by integrated spatial analysis. In addition, the model was
meant to explore de object-oriented technology applied to evaluate model results and existing information from
traditional survey. Since all existing products were only based upon field work attributes with satellite paper images and
aerial photographs interpretations, expectations were that incorporated DTM procedures could aid land vulnerability
interpretations where the county area was divided into highlands, due to erosion susceptibility, and low lands, due to
drainage condition. The susceptibility for reforestation prioritised the rolling areas subject to land sliding, besides the
suitability for horticulture at the low land areas of the west zone that are still under agricultural use. The vulnerability of
the lands evaluated the environmental fragility for urban and agricultural growth. The map for environmental quality of
the lands was obtained by overlaying vulnerability data with current land use from supervised classification of digital
satellite images, stressing the level of urban pressure upon natural attributes and how the environment reacts under these
conditions. Furthermore, it could be used to search for social-economic patterns, as proximity to urban slams,
improving the interpretation method for environmental fragility according to urban and agricultural growth.
1.2 Environmental Planning Context
The Municipal Secretariat for the Environment (SMAC - Secretaria do Municipal do Meio Ambiente), executive
organism created in 1994, has developed technical studies in order to protect new areas, and to accomplish areas already
planed for preservation. The scheme also includes the Municipal Council for Environment and the Environmental
Conservation Fund, both as part of the "Megacities Project Book", published by the United Nations, which in 1990,
chose the 16 best projects in the field of environment in cities inhabited by more than 10 million people. The specific
reforestation scheme, so called “Mutiräo Reflorestamento”, is presently active in 56 hillside communities, located in
different geographic areas of the Municipality of Rio de Janeiro, thus preventing landslides and rain caused erosion. Up
to now, the scheme reforested 500 ha (5,000,000 m?) and planted a million seedlings of native Atlantic Rainforest
species, employing 580 local hillside villagers. In order to prevent new deforestation caused by the growth of hillside
communities, a "non-growth" pact was settled between the Government and hillside village leaders, aiming to freeze the
hillside communities at their present size. The annual cost of the project is around US$ 9 million. Protected Areas are
areas of the Municipality that, due to their ecological value, have a special legal statute of use and occupation of the
soil. Some of the most important protected areas are of Environmental Protection and Urban Recovery, Protection of the
Cultural Environment, Relevant Biological Concern, Biological Reserves, Ecological Stations, National Parks, State
Parks and Areas of Permanent Preservation, as in Figure 1 (SMAC, 1997).
Figure 1. Landscape pictures of some p otected areas (from left to right: Grumari, Marapendi e Jequiá; € SMAC).
1.3 General Description of the Area
The municipal district of Rio de Janeiro is located from 43? 05' 54" to 43? 47' 32" Longitude West and from 22? 44' 44"
to 23? 04' 51" Latitude South, having the official area of 125,530 ha. The relief is constituted basically by three great
well-known crystalline massifs such as Tijuca, Pedra Branca and Gericinó and by the sedimentary coastal plain
comprised by Jacarepaguá, Sepetiba and Guanabara bottomlands. At the massifs there is a predominance of
precambrian gneiss rocks, of varied constitution, penetrated by intrusive granite and alkaline rocks. Those factors
influence the characteristics and distribution of the soil, mainly considered by its strong influence on gully and sheet
erosion, besides a close relationship to climate and vegetation cover. The climate characterisation for the working scale
has considered the following Kópen classes: Cfa; Af; Am; Cwa; Aw. This climatic variation facilitated the correlation
of soil units and higher humidity degree of east faced slopes, besides typical formation of latosol B horizon of west
faced slopes with the mesothermal climate at massif tops. Regional vegetation was characterised as follows: five
different groups of forest types (subperenial tropical forest, subcaducous tropical forest, caducous tropical forest,
evergreen meadow forest, and subperenial meadow forest); grassland meadow; halophyte meadow, sandbanks, and the
mangrove swamps. According to current land use map, the district maintains 19.549 ha of preserved forest vegetation
with minor changes of native vegetation, which corresponds to 15.6% of the total area.
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International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000.
