Revision as of 13:27, 7 May 2014 by RinekeOostenrijk
Parts of Land degradation
|Implemented in computer model|
Key policy issues
- In what parts of the world have human-induced changes in land and soil conditions occurred?
- What are the future risks of soil degradation?
- To what extent are ecosystem functions lost by soil degradation, adding to local and global concerns about food security, biodiversity loss and climate change?
Input Land degradation component
|IMAGE model drivers and variables||Description||Source|
|Number of wet days - grid (historical data)||Number of days with a rain event, per month; assumed constant after the historical period||CRU database|
|Land cover, land use - grid||Multi-dimensional map describing all aspects of land cover and land use per grid cell, such as type of natural vegetation, crop and grass fraction, crop management, fertiliser and manure input, livestock density.||Land cover and land use|
|Precipitation - grid||Monthly total precipitation.||Atmospheric composition and climate|
|Temperature - grid||Monthly average temperature.||Atmospheric composition and climate|
|Initial land cover, land use - grid||Includes current state (intensive agriculture use, extensive agricultural use, no use) of land area and erosion protection represented by greenness index (NDVI = Normalized Difference Vegetation Index).||GlobCover database|
|Initial temperature, precipitation - grid||Global high resolution climate data from WorldClim.||WorldClim database|
|Slope - grid||Terrain slope index.||IIASA|
|Soil types and profiles (S-World)||Soil profiles based on the HWSD (Harmonised World Soil Database) and on the ISRIC-WISE international soil profile dataset||S-World database, HWSD database|
|Weighting factors for temperature, precipitation, land use and slope||Weighting factors for the contribution of temperature, precipitation, land use and slope on distribution of soil properties.||expert judgement|
Output Land degradation component
|IMAGE model variables||Description||Use|
|Erosion risk - grid||Risk of soil erosion caused by water.|
|Change in soil properties - grid||Change in soil properties, such as clay/sand content, organic carbon content, soil depth (topsoil/subsoil).|