A temporal behaviour analysis of the land cover l band backscatter in the Tapajós national forest, state of Pará, by using jers-1 images / Análise do comportamento temporal do retroespalhamento na banda L da cobertura da terra na Floresta do Tapajós, Pará, utilizando imagens JERS - 1

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

05/05/2000

RESUMO

The temporal evolution of the backscatter for several land cover types in the Tapajós National Forest, Brazilian Amazonia is analyzed using JERS-1 images. Five JERS-1 images were acquired in the dry season from 1993 to 1997. Samples of the studied land cover types were identified after the analysis of a Landast5/TM data set of 12 images obtained from 1984 to 1999. The following land cover types were investigated: bare soil, agriculture, pastures, forest regrowth from one to 23 years old and primary forest. The results show that the behavior of the regrowths stands is influenced by the previous land use and by human impacts as fires and selective logging. It was observed that the backscatter behavior of young regrowth stands originated from abandoned slashed and burned areas differs from those originated from abandoned agriculture activities. The backscatter of the former increases in a faster rate than that of the latter. The backscatter of old regrowth stands also behaves differently depending on the occurrence or absence of selective logging. The first case presents an oscillating pattern, while the second presents either a progressive trend or a stable pattern depending on the age of the stand. This assignment had an investigating feature, whose goal was to verify the possibility of using the backscatter temporal evolution as data source in studies that focus the land cover changes in tropical areas. The results of this research can be applied to the inference of the states and transition rates of the vegetation cover in Tropical Rainfall Forests areas, which may improve biomass production models of tropical regions and refine the assessment of regional Carbon balance. Besides, with the results, may be possible to make a radar image classifier algorithm, that observes the backscatter temporal evolution to take the right decision in the classification. To improve the results it is suggested a higher number of samples and radar images.

ASSUNTO(S)

jers-1 análise multitemporal floresta tropical estruturas de florestas floresta nacional do tapajós. keywords: synthetic aperture radar jers-1 multitemporal analysis tropical forest wooden structures tapajós nacional forest radar de abertura sintética (sar)

ACESSO AO ARTIGO

Documentos Relacionados