Oliveira, Ronaldo Pereira de 
2. METHODOLOGY 
2.1 Survey, Interpretation, and GIS Procedures 
2.1.1 Soil Survey: This study was executed in partnership of Embrapa Solos (National Center for Soil Research) 
and SMAC in order to provide strategic information applied to “Mutiräo Reflorestamento” and other specific planing 
actions. The existing soil survey information (Embrapa, 1980) had firstly minor legend revisions considering few 
updates on original criteria (Embrapa, 1999a), in order to accomplish new project goals. The revision was based on 
pedogenesis correlation of soil horizon notations and analytical results from old and new soil, besides a complete 
conversion of analytical units to international standards. Geometric representations of soil class boundaries were 
checked according to new soil types (Embrapa, 1999a), update information of urban areas, beach, dune, swamp and 
exposed rocky covering (Rio de Janeiro, 1997), and mangrove field survey, at 1:10,000 scale, conduced by SMAC. The 
final step was to input fieldwork and analytical information in SIGSOLOS database (Embrapa, 1997), providing a 
Storage structure of thematic attributes that can be linked to the topology of geometric attributes structured in GIS. 
2.1.2 Land Suitability for Reforestation and Horticulture: The disordered occupation of hilly areas in Rio de 
Janeiro has been source of serious environmental damages, in special by water erosion at steep slope areas and granite 
mining. In this way, reforestation of degraded hilly areas was considered as main focus of this study. Another strategic 
aspect considered was the evaluation of remaining horticulture observed in west zone low lands, providing flat areas of 
alluvial, gley, and organic soil types besides proximity to market. The methodology for this interpretation was adapted 
from Ramalho F. and Beek (1994), and it was further applied to the updated soil map. Two types of land utilisation 
systems were defined as basis of distinct evaluation criteria, thus considering different species for both reforestation and 
irrigated horticulture. The reforestation system was defined for areas with step declivity higher than 3%, focusing on 
erosional processes due to deforestation. For this purpose arboreal vegetation has been chosen for hilly areas because 
good results obtained by the “Mutiräo Reflorestamento” project at slums’ neighbourhoods, presenting fast vegetative 
growth and profuse rooting system. The level of management system also includes options for application of nutrients 
and fertilisers. Another aspect considered for reforestation was the remaining mangrove ecosystem, where two especial 
classes define either a preservation status or an identification of native species to restore the original coverage. The 
irrigated horticulture system was defined for areas with step declivity lower than 20%, mainly focused on the west 
portion of the district because gentile relief aspect and fertile soil types, although problems of tionic and salic 
properties. The remaining crop coverage is characterised by small and spread sites, so that being under pressure of 
urban expansion. Management systems considered nutrient and water deficits, soil drainage class and erosion 
susceptibility, and availability for irrigation or drainage systems. The final evaluation system considered five limiting 
factors according to basic environmental quality indicators. Expert rules to estimate degrees of limitation and to 
represent relationship of factors were implemented into spreadsheet functions described in Embrapa (1999). 
2.1.3 Land Vulnerability: The ecosystem vulnerability evaluation was considered as cause of environmental 
inadequacy to deal with natural stress factors. In this sense, vulnerability was understood as being an association of 
essential qualities of the ecosystem, such as: stability, persistence and restoration potential (Batisdas, 1995). In this 
context, the term land vulnerability is related to the land fragility for purposes of agricultural exploration, highway and 
railroad construction, sanitary swelling and cemeteries, contamination risk assessment, ecological recreation, and urban 
hlands. 
     
  
  
  
  
  
  
  
  
  
  
  
fuzzy and gentile : subcaducous tropical 
Low gn 200 gradual Bo ondulating forest 
: clear and : subcaducous tropical 
Intermediate (M) 100-200 abrupt no ondulating - forest 
strongly caducous and 
High (A) 50-100 - yes : slight subcaducous tropical 
ondulating forest 
: ial tropical 
Very High (MA) «50 - yes mountainous | moderate xad "romeo 
Extremely High (EA) - - no steeped abundant rangeland 
  
  
! - Considered as indicator of texture gradient variation between soil horizons. 
? - Considered as reflection of soil hydrologic conditions. 
  
  
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000. 1075