Avaliação dos efeitos da resolução espacial na estimativa de áreas desflorestadas em três padrões distintos de paisagem / The evaluation of spatial resolution effects over estimates of deforested ares at three different landscape patterns

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

Deforestation is the major problem that affects forests all over the world, including the Amazon Rainforest, which territory has been monitored by National Institute for Space Research since 1974. For so, INPE has been using Thematic Mapper and Enhanced Thematic Mapper Plus images with 30 meters of spatial resolution, on board of Landsat 5 and 7 satellites respectively. Aiming to get a major autonomy in space imaging, the Brazilian Space Program expect to construct a few remote sensing satellites with different specifications than Landsat ones, including spatial resolution. This brings doubts to the user community of information obtained from projects like Amazon Gross Deforestation Estimation Project about the continuation of those projects. The main goal of this research was to evaluate the spatial resolution effects (30, 60, 120 and 240 meters) over the estimate of deforested areas at three different landscape patterns (small properties, medium and large properties and fishbone pattern) in a specific region of the Legal BrazilianAmazon. The methodology consisted in: (a) spatial degradation of TM/Landsat 5 images with 30 meters of spatial resolution, obtained in 1985 and 2000, to the new spatial resolution values (60, 120 and 240 meters); (b) elaboration of the corresponding thematic maps (categories forest, non-forest and water), applying supervised classification (MAXVER), followed by visual inspection, on the images of the bands TM3, TM4 and TM5; (c) to obtain the increasing deforestation estimation for each spatial resolution using 150 cells with random spatial distribution, over positioned on the maps; (d) to verify the existence of linear relationships between the values of deforestation increasing estimation obtained from 30 meters spatial resolution and those resulting from 60, 120 and 240 meters; and (e) to utilize multiple linear regression for verifying the influence of the deforestation pattern (fishbone, small properties and medium and large properties) over the estimation of deforestation increasing estimation, according to the adopted spatial resolution. The results indicate to be minimum the impact of the spatial resolutions adopted until 120 meters on the estimation of deforestation increasing in the study area for the deforestation patterns studied. The spatial resolution degradation produced an underestimation of the small deforestation increasing detected on 30 meters spatial resolution. However, the effects of the spatial resolution adoption on the deforestation increasing estimation were statistically significant only in the 240 meters spatial resolution and in the fishbone pattern.

ASSUNTO(S)

sensoriamento remoto filtragem espacial remote sensing remote sensing resolução espacial deflorestation spatial filtering amazon region (south america) região amazônica (américa do sul) spatial resolution rondônia rondônia (state) desflorestamento

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