Section: New Results
Desertification monitoring from AVHRR data
The INRIA P3+3 project DESMED has been starting since 2006. It involves the Clime project, CNR in Italy, INSAT in Tunisia, and the Ibn Tofail University in Morocco. The goal of DESMED aims at analyzing long term time-series of vegetation indices acquired by the NOAA-AVHRR sensor, in order to characterize desertification processes occurring in Northern Africa and Southern Italy.
Currently, the achievements of the project are: First, databases have been established for documenting learning sites (Menzel Habib and Jfarra in Tunisia, Salento peninsula in Italy) with classification of Landsat images at different dates, and co-registered time-series of weekly and monthly vegetation indices from 1995 to 2006. Second, definition of a processing chain for characterizing land degradation from NOAA data: this processing chain models time-series of vegetation indices by polynomials, and represents them using a selected set of parameters. The characterization of desertification is then performed in the vector space defined by these parameters. Currently, the work concerns the automatic selection of parameters for distinguishing safe areas and areas undergoing desertification on the basis of pluri-annual time series of vegetation indices.