Land cover quickly changes in the Mediterranean area: forest progress on agricultural abandoned lands when scattered urban zone progress into forest areas. As forest fire risk in linked to spatial arrangements, land cover change implies quick changes in forest fire risk level. Cartographic fire risk models elaborated by research for engineering are usually static, and do not take into account this temporal dimension. However, decision-makers need risk change previews for judicious land management planning. A framework to integrate time in spatial risk models is proposed. It is funded on integration of land cover change (vegetation and urbanisation) dynamic models, and forest fire risk models in order to design an environmental decision support system (EDSS). Such a system has to integrate geographical information systems (GIS) with modelling and simulation softwares of land cover changes (vegetation, urbanisation). This spatio-temporal integration can take different forms, from weak coupling up to intelligent integration. Two integration strategies are studied.