Characterization of the alternative to slash-and-burn benchmark research area representing the Congolese rainforests of Africa using near-real-time SPOT HRV data
Ps. Thenkabail, Characterization of the alternative to slash-and-burn benchmark research area representing the Congolese rainforests of Africa using near-real-time SPOT HRV data, INT J REMOT, 20(5), 1999, pp. 839-877
This study used four near-real-time multispectral Systeme pour l'Observatio
n de la Terre (SPOT) high-resolution visible(HRV) images to establish land
cover and forest classes of relevance to slash-and-burn agriculture. The st
udy was conducted in 1.43 million ha of the Alternative to Slash-and-Burn (
ASB) global benchmark research area for Africa selected as representative o
f the entire Congolese basin of Central Africa and located in Southern Came
roon. The land cover and forest classes mapped have different impacts on gl
obal phenomena as well as their own management challenges and include slash
-and-burn dominant farmlands, Chromolenea orodata dominant short-fallows, I
mperata cylindrica dominant weeds, long-fallows or regenerated forests, rap
hia palm-dominant lowlands, permanently flooded swamp forests, and primary
and secondary forests. In order to map these distinct and complex classes t
he study proposes and implements a piecemeal approach to classification inv
olving stratification of the image into several distinct discrete subsets o
f forest corridors, lowlands, and uplands. The approach involves the use of
image texture indicators in conjunction with ground-truth data to divide t
he image into discrete subsets, performing unsupervised classification on t
hese discrete subsets, masking problem classes and reclassifying them, edit
ing certain spectrally inseparable areas, adopting post-classification stra
tegies, and finally mosaicking the discrete subsets into one seamless image
. This approach led to an overall mapping accuracy of 82.4% with individual
classes mapped at accuracies above 72.9% (user's), and above 66.7% (produc
er's).