The Integrated Desertification Index (IDI) was developed (Santini et al., 2010) to combine in a semi-quantitative way multiple processes leading to desertification and simulated via mechanistic to empirical models. The outcomes from the modelling efforts on different desertification components are standardized and weighted so to be inserted in the IDI formulation. The peculiarity of IDI is that it also takes into account the temporal dimension of land degradation and desertification phenomena by integrating the standardized value of current hazards, simulated for the single desertification components, and their variation from the past, so to consider that some processes can have different either magnitude or rapidity.

The IDI was implemented in GIS to allow spatially explicit evaluations, and although it was initially applied in Sardinia Island (Italy) taking into account specific land degradation processes (overgrazing, soil erosion by water and wind, sea water intrusion, loss of vegetation production and of soil fertility), the IDI is scalable and versatile to include additional or alternative processes, and to be applied in different study areas.

References:

• Santini M., Caccamo G., Laurenti A., Noce S., Valentini R., 2010. A multi-model GIS framework for desertification risk assessment. Applied Geography, 30(3), 394-415.