Global Assessment of Human-induced Soil Degradation (GLASOD)

The UNEP-funded, GLASOD project (1987-1990) has produced a world map of human-induced soil degradation. Data were complied in cooperation with a large number of soil scientists throughout the world, using uniform Guidelines and international correlation .  The status of soil degradation was mapped within loosely defined physiographic units (polygons), based on expert judgement . The  type, extent, degree, rate and main causes of degradation have been printed on a global map, at a scale of 1:10 million, and  documented in a downloadable database. Information about the areal extent of human-induced soil degradation can be found in an explanatory note.  

                     
                       Printed GLASOD map (mercator projection) 
 

GLASOD applications:

• International policy makers and planners (e.g. UNEP, FAO, WRI) 
• National policy makers and planners 
• International conventions and programmes (CCD, Kyoto protocol, UN-CPB, IGBP) 
• Researchers at national and international level (NARI’s, CGIAR, universities) 
• Education professionals (teachers, professors, etc.) and students 
• Environmental organisations (general public awareness) 
   

 GLASOD limitations:

• Small scale: not appropriate for national breakdowns
• Expert judgement: qualitative and (potentially) subjective
• Limited number of attributes due to cartographic restrictions
• Visual exaggeration: each polygon which is not 100% stable shows a degradation colour, even if only 1 to 5% of the polygon is actually affected
• Extent classes (5) rather than percentages
• Complex legend: combined extent and degree (severity) for four major degradation types (water and wind erosion, physical and chemical deterioration)
• Only “dominant” main type of degradation is shown in colour
• Degradation sub-types only shown by codes
• Only “bad news”
    

Follow-up assessments:

• Regional assessments of soil degradation status - South and Southeast Asia (ASSOD), Central and Eastern Europe (SOVEUR) 
• Land Degradation Assessment in Drylands (LADA) - Global project, under UNEP/FAO. ISRIC and WUR Centre for Geo Information are responsible for the spearpoint Global Assessment of Land Degradation and Improvement based on 22 years of fortnightly NDVI data [2006 - 2009]
  
  

Further information: