Résumé
Very high resolution (VHR) satellite images provide crucial information on fast changing coastal regions of the world. Within the framework of the INDESO project, we designed a specific application dedicated to the monitoring of mangroves in Indonesia. In this work, we focused on the case study of the Perancak river estuary, Jembrana, Bali. The estuarine area was subject to aquaculture development during the 80's and most of the mangrove forest was cleared. Since the 90's, mangroves are progressively reintroduced thanks to plantation practices. Now, many shrimp ponds are abandoned. We based our analysis on a temporal series of VHR satellite images acquired since 2001 in the aim of following -up 9 years of changes occurring in mangrove vegetation. We map and quantify the trends of evolution in mangroves surface extents, forest types and structure (young, adult, mature) after ground trothing surveys. Overall, the Perancak estuary is currently greening, i.e. increasing extent and continuous growing of mangroves are observed. However, the estuarine hydrology is still constrained by ponds dykes and plantations are monocultures of Rhizophora species which are probably not the initial dominant species. The sustainability of the Perancak estuary must be questioned confronted to this greening evidence. (Résumé d'auteur)