The WAW initiative (World Agricultures Watch) intends to elaborate a worldwide observatory collecting information on agriculture in different countries and its evolution. Madagascar has been chosen as one of the pilot countries. The geographical area of the studywhich has been chosen is the lake Alaotra. The study of the notions of vulnerability, resilience, durability and viability has been the main point concerning the choice, the calculation and the analysis of the necessary indicators leading to the elaboration of the observatory.Three different data lines havebeen chosen: i) The database from the ROR, with annual data from 2005 to 2008 for 500 households ii) The database from the agricultural diagnosis BV-Lac in 2007 (110 farms) and iii) The databasefrom RFR, with 48 farms in 2009.This paper presents some results with farming systems modeling using the two databases from the BV-lac development project showing the indicators used through the example of a technical change with adoption of conservation agriculture.

The project Observatory for World Agricultures wants to elaborate a worldwide observatory collecting information on agriculture nin different countries and its evolution. At the moment five countries have been chosen as countries of reference, Madagascar is one of them. The geographical area of the study which has been chosen is the lake Alaotra. The study of the notions of vulnerability, resilience, durability and viability has been the main point concerning the choice, the calculation and the analysis of the necessary indicators leading to the elaboration of the observatory. Three different data lines have been chosen : i) The data base from the ROR, ii) The database from RFR and iii) The database from the agricultural diagnosis Bv-Lac (Durand, Nave& Penot). This paper presents some results with farming systems modeling using the two databases from the BVlac development project showing the indicators used through the example of a technical change with adoption of conservation agriculture.

Résumé: Le projet Observatoire des Agricultures du Monde (OAM) vise à construire un observatoire mondial permettant de donner des informations sur les agricultures des différents pays ainsi que sur leurs évolutions. A l‟heure actuelle, cinq pays ont été choisis comme pays pilotes, Madagascar en fait partie. La zone d‟étude qui a été retenue est le lac Alaotra. L‟étude des notions de vulnérabilité, résilience, durabilité et viabilité a guidé le choix, le calcul et l‟analyse des indicateurs nécessaires à la construction de l‟observatoire. Trois bases de données différentes ont été retenues dans le cadre de cette étude : - Les bases de données du Réseau des Observatoires Ruraux (ROR) - Les bases de données du Réseau de Ferme de Référence (RFR) - Les bases de données du diagnostic agraire BV-Lac (Durand et Nave) L‟étude nous a permis de faire l‟état des lieux des différentes bases en mettant en évidence les points forts et les points faibles de chacune d‟elles, et d‟obtenir des résultats socio-économiques, à l‟échelle du système d‟activité.