In this workpackage the GLOWA project provides satellite remote sensing data that maps the change in land cover over several years in the Volta basin. The satellite derived change data is further analysed within a cellular automata (CA) model to ascertain the change drivers, meaning the causalities of the change.

The remote sensing land cover was mapped, with a standardized legend, using data from several satellite instruments including Landsat, MODIS and DMSP satellite data.
The project achieved to map land cover change processes between several years, irrespective of the input satellite data system used and uniquely so since not every image pixel that makes up an satellite image is mapped, but pixels are grouped into broad and functional change processes.

The example (Figure) shows the land cover change mapped processes between 2000 and 2006 for an area in south western Burkina Faso.
The colours represent change processes, being mainly change transformation, i.e. a complete change of land cover from one date to the next (blue and red areas), and change modifications, i.e. if the land unit is slightly altered, but the land cover does not completely change (shades of green).
The black arrow shows the location of the Bontioli National Park in Burkina Faso, where between 2000 and 2006 a slight modification of the shrub, or tree density layer occurred (visible in shades of green). Rigorous deforestation and land transformation (in red and blue) are particularly obvious in the area surrounding the Bontioli Park.

The cellular automata was used to explain the change processes, mapped from the satellite remote sensing.

The result from the change between 2000 and 2006 shows the population density, the expansion of croplands, and laterally the distance to roads to be responsible for land cover change processes - these being primarily the transformation of woodlands to croplands and forests to croplands.
The factors responsible for the change processes are thus not merely singular, but mostly a mix of several factors.
The change drivers were inferred for time frames from 1990 onwards until 2005 for an area in northern Ghana, and from 1990 to 2006 for an area of 28.000km² in south-western Burkina Faso.

The change maps from satellite remote sensing are available through the project, and the change mapping process can be repeated and updated since broadly functional processes are used.

Person in Charge: Tobias Landmann