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TitleEvaluation of RADARSAT for Land Use and Land Cover Dynamics in the Southwestern Brazilian Amazon State of Acre
AuthorKux, H J H; dos Santos, J R; Ahern, F; Pietsch, R W; Lacruz, M S
SourceCanadian Journal of Remote Sensing vol. 24, no. 4, 1998.,
Alt SeriesEarth Sciences Sector, Contribution Series 20042878
PublisherInforma UK Limited
Mediapaper; on-line; digital
File formatpdf
Released2014 07 31
AbstractIn order to facilitate the incorporation of RADARSAT data into on-going programs for monitoring land use and land cover changes in the Brazilian portion of the Amazon basin, a rapid assessment of the visibility and detectability of features of interest was carried out and on the dynamics of change of these features with time. RADARSAT images were acquired for five dates in 1996: one in April, one in May and three in October. These have been analyzed qualitatively and quantitatively in conjunction with aerial photographs. Field trips were made concomitantly with both first and second series of RADARSAT overpasses; a Landsat - TM image was obtained from June 14, 1996. The most significant findings were Visual interpretation of Standard Mode RADARSAT images could be used to detect urban areas, streams, and the general pattern of deforestation resulting from human settlement on all five images. The contrast between deforested areas and the primary forest was variable, being the greatest on an afternoon overpass at the end of the dry season, when no rain was recorded in the previous 24 hours. Compared to the undisturbed or minimally disturbed upland rainforest, anthropic areas were observed to exhibit much larger temporal variations in backscatter (up to 4 dB in the case of recently-burned forest); under the proper conditions of recent precipitation at the end of the dry season, RADARSAT imagery appears to be a very sensitive indicator of forests which have been recently burned. With C-HH radar, the use of multitemporal data will increase the reliability of detecting and mapping deforestation; the ideal two date combination would be to obtain one image under very dry conditions and a second image following a recent rainfall.

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