GIS Unit - Itigi thicket project

This project is a collaborative project between the Royal Botanic Gardens, Kew and the Department of Geomatic Engineering at University College London, monitoring the vegetation of the Itigi thicket using Landsat TM images.

Animation showing the deforestation of Itigi thicket from 1976 to 1999 (December). Thicket is in green, on Landsat band 4 backdrop.

Samuel Almond produced this thesis for the MSc Degree in Geographic Information Science (GIS), at UCL, working closely with Justin Moat, Spatial Information Scientist at Royal Botanic Gardens, Kew and Paul Smith at Kew's Millennium Seed Bank.


Various classification procedures were employed to determine the rate of Itigi thicket deforestation in northern Zambia. Due to the effects of seasonality and the yearly variation in precipitation observed in dryland regions, in was deemed inappropriate to apply change detection techniques based upon radiometric image properties. To separate various vegetation cover types, it was necessary to devise an approach which takes into account the growth patterns of the thicket. The application of a binary mask reduced misclassification, as cover types which had statistically similar spectral signatures were removed from subsequent analysis. Once accurate thicket extent had been derived it was then possible to determine the rate of deforestation between 1976-1999. It was discovered that thicket extent has reduced by 71% within the last 23 years. Continuation of these removal rates would lead to total destruction of the remaining Itigi thicket in Zambia within the next 9-19 years.

Itigi thicket study area

Itigi thicket study area in Northern Zambia. The study area is in Northern Zambia, close to the international border with Zaire and Tanzania. The region of interest encompasses an area of over 1,800,000 hectares. 1990 Landsat 5 False colour composite (bands 2 - blue, 3 - green, 4 - red).

Animation showing deforestation of thicket from 1976 to 1999 (December).  GIF (193 Kb) or AVI (1.4 Mb)

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