Land cover changes in Africa : Multitemporal change vector analysis at coarse scale and change processes categorisation with high spatial resolution data

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Context and objectives

Changes in land-cover have important implications for a range of issues such as biosphere-atmosphere interactions, species and genetic diversity associated with endangered habitats, soil conditions, water and sediment flows, and sustainable use of natural resources in the development process of human societies. It is believed that, at a global scale, land-use changes are cumulatively transforming land cover at an accelerating pace, mainly in the tropics. However, quantitative data on where, when and why such changes take place globally are still lacking.
The objective is to test, improve and adapt a change detection method designed for high temporal resolution data, such as those of VEGETATION, in order to address the need for global data on the nature and magnitude of processes of land-cover change.

Project outcome

Expected scientific results

A. Application of the temporal change-vector algorithm to detect changes in land-cover to 10 years (1982-1991) of monthly NOAA AVHRR GAC data. This has led to continental scale maps of land-cover change, which simulate the results that could be generated from the VEGETATION instrument.
B. Creation of a database of spatially representative time series of high resolution remote sensing images. Sixteen sites all across Africa have been analysed.
C. Validation with fine resolution remote sensing data of the coarse resolution land-cover change maps. This allowed to assess the accuracy and robustness of the change detection algorithm used and to test a variety of metrics of change.
D. Test and validation of the method on the first 2 years of SPOT VEGETATION data (April 1998 to March 2000).
Project leader(s): UCL - Georges Lemaître Centre for Earth and Climate Research
Location: Region:
  • West Africa