Rift Valley Fever (RVF) is the first historical brick of RedGems. This disease has been studied by the Emercase project since 2000. This study was continued by AMMA project. Historical and new results are presented and valued in this part of the RedGems system. The main goal of these projects is to identify linkages between small water extent (=ponds), changing environment and dynamics of mosquitoes (=vectors) diffusing the RVF. Risks/hazards maps are produced and contribute to the implementation of the RVF Early Warning System (RVFEWS).