Determination of vegetation parameters through measured and simulated AVHRR data over SALT-HAPEX-Sahel site

Vegetation-related information is critical for modelling hydrological processes. Remotely sensed spectral data provide powerful means to characterize vegetation state. In this study, we investigate the opportunities of such data when an automatic classification is applied to time-series of remotely sensed data. The analysis is then conducted by interpreting the classification results in terms of surface physical parameters. The method consists in (1) selecting several control points in the HAPEX-Sahel square degree, during the rainy season of 1991 and 1992, and (2) comparing the temporal evolution of the albedo-based normalized difference vegetation index (NDVI) values and those deriving from the classification. The result shows that there is similarity between the behaviour of the 1991 and 1992 temporal profiles estimated at all control points.