Seasonal variations of water status and SPOT NDVI in Mediterranean woody plants

Facing the problem of fire risks, it is useful to test accurate tools to prevent this flail. Remote sensing and vegetation indices are suitable to estimate fire risks. The aim of the study was to follow the evolution of water status of various Mediterranean vegetal communities and of Normalised Difference of Vegetation Index (NDVI) calculated from SPOT images. The water status was studied using the water content and the water potential. Annual variations of the water status and NDVI show both the influence of the season and the type of vegetation community. At the end of the summer, the hierarchy of vegetal communities found for NDVI and water status are similar. At this period, sites composed with arborescent species have higher water content, water potential, and NDVI than sites composed with arbustive species. For the other seasons or for a precise site, there is no correlation between NDVI and water status.