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Geo-Spatial Data Infrastructure in Brazil : Some Keynotes
Deforestation, here, refers to the conversion of areas of primary forest physiognomy by anthropogenic activities, for the development of agriculture and cattle raising, detected by orbital platforms. Gross deforestation indicates that areas in process of secondary succession or forest recovery are not subtracted in the calculation of the extent and the rate. The above definition does not include areas of forest affected by selective logging activities or wild fires, which are object of specific reports by INPE.
Color composite satellite images at a scale of 1:250,000 allow the identification of changes in forest cover of 6.25 ha and larger. The Brazilian Amazon is covered by 229 of such images, which are interpreted for the boundaries between primary forest and other types of non-forest vegetation.
At each assessment, the areas of new deforestation are delimited. The deforested areas are outlined in overlays, which are subject to a rigorous quality control. When approved, the overlays are scanned and integrated into a Geographical Information System to provide the localization and extent of the deforested areas.
The digital data are converted to a format that allows the presentation of deforestation in any geographical format, for instance, large vegetation classes, municipalities etc.
Each assessment involves approximately 50,000 person x hours, 10,000 machine x hours hired by Fundação de Ciência, Aplicações e Tecnologia Espaciais - FUNCATE. In addition to the 70 specialists involved in the project, a team of 15 researchers from INPE accompanies all phases of PRODES, ensuring its high quality control.
- AMAZONIA Information System- it is a GIS that integrates deforestation areas in several years, county area and vegetation types.;
- DATA ANALYSIS- there are three main problems investigated by analysis of the datasets:
- the estimation of the rate of deforestation per year and among several years (cloud cover, errors that difficult integration of the two datasets, errors of image analysis, digitization and georeferencing due to the poor quality of some maps in the Amazon region)
- the assessment of how much deforestation has been occuring inside the different types of vegetation (deforestation may have different impacts depending on the type of vegetation in wihch it occurs);
- the assessment of deforestion by county (the amount of deforestation inside each county may be important for different socio-economical studies);
PRODES, in addition to the extent and rate of gross deforestation, provides the spatial distribution of critical areas in the Amazon. For instance, in 1998, more than 78% of the deforestation was concentrated in 44 of the satellite images analysed. PRODES data are overlaid on the Vegetation Map from the RADAMBRASIL Project-FIBEG to identify the forest physiognomies affected by antropogenic activities.
The distribution of the deforested areas by classes of size is used by governmental and non-governmental agencies as an indicator of the possible causes of deforestation in the Amazon. The annual results presents the distribution of the mean rate of deforestation (% / year) by classes of size. and the distribution of the mean rate of gross deforestation for years for the following thematic classes:
- early primary succession communities;
- Amazon white-sand woodland;
- dense savanna woodland;
- contact zone;
- seasonally deciduous tropical forest;
- open tropical rain forest and dense tropical rain forest, respectively.
The annual rate of gross deforestation in the Brazilian Amazonia tends to concentrate in a relatively small fraction of the 229 TM-Landsat scenes that cover the entire region. For example, for the period 1996/1997, more than 78% of the mean rate of gross deforestation in Amazonia concentrated in 44 scenes, representing approximately 19% of the total of 229 images.
The sample used to generate the provisional estimates of the mean rate of gross deforestation are selected so as to include scenes with the largest rates. This procedure was adopted in 1997, which involved 47 scenes. The estimated rate was later found to be in good agreement with that based on the analysis of all scenes, within 1.5%. The second estimate, for the period 1997/1998, based on 46 images, was in error of 3,1% in relation of the final estimate.
Ecological-Economical Zoning for Brazil
- This project is carried on by the Brazilian Government:
- National Institue for Space Research-INPE
- Brazilian Institute for Statistic and Geography-IBGE
- Stategic Affairs Office-SAE
- In 1989 the Brazilian Government has created this program which main objective is to develop a territorial zoning to help the government planning policy, designed to regional development and improvement of social, economical and environmental aspects
- The two main approches are: agroecological (land use and the human pressure over the environment) and ecological-economical (territory reorganization based on the society/environment relation)
Ecological - Economical Zonning for Brazil
- Legal Amazonia (5 millon square kilometers) was the priority area in the begining: Acre, Amapá, Amazonas, Mato Grosso, Pará, Rondônia, Roraima, Tocantins and portions of Maranhão and Goiás states
- This program was also developed in Pernanbuco (northeast region) Mato Grasso do Sul (central-west region) states and Curitba (south region) and São José dos Campos (southeast region) cities.
- In Amazonia Region were trained 120 people, in 9 multidisciplinar training courses (geologist, geographer, agronomist, forest engineer)
- All methodology was developed by INPE and IBGE and LANDSAT-TM imagery, SPRING, maps and social-economical datas were used
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