Land degradation in dry and sub-humid lands

Monitoring of land degradation (e.g. soil erosion, overgrazing, habitat conversion) is a key element for meeting the Biodiversity 2010 target of the United Nations Convention on Biological Diversity (UNCBD).

GeoVille has developed for the UNCBD a methodology to identify areas of potential land degradation. The approach is based on a spatial and thematic harmonisation of the IGBP 1992/93, GLC2000 and Globcover2005 data.

The indicators developed within this study yield information on the current and historic global extent and composition of dry and sub-humid lands as well as their development between 1992 and 2005. The extent and land cover composition of dry and sub-humid lands are described by maps and continental to global statistics over time.

Areas affected by land degradation in Mexico Copyright ©: ESA, INEGI, UNCBD, GeoVille

Hotspots are being monitored with higher resolution satellite data such as SPOT and have yielded in Mexico an overall accuracy of 80% against data obtained from national sources.

Differences are flagged as potential land cover changes. These potential change areas are further analysed using long-term vegetation and leaf area indices to confirm changes in vegetation vigour. In dry areas land degradation is expressed as “change to barren land”, indicating a change from a higher form of land use (e.g. agriculture, forestry) to unused, barren land.

Areas affected by land degradation in Mexico Leaf Area Index 1990 – 2000 – 2005 for Central America: Copyright ©: ESA, INEGI, UNCBD, GeoVille