Essential to risk studies, vulnerability analysis of the assets of an area is often not suitable for practical application. It is usually more an assets census than a real vulnerability assessment, facing a given hazard. Its intersection with the hazards zoning poses also many methodological, cartographic and operational problems. This work starts with the key concepts of risk, thanks to a review of French and international literature study. Then, it provides a procedure which allows precise knowledge of the local vulnerability, available to all types of hazards and applicable to all areas. Finally, in order to get an overall perspective of risk, assets vulnerabilities are crossed with the hazards areas, in accordance to the spatial distribution of both components and using innovative geomatics operations. As part of this study, this methodology will be applied to the rivers flooding and overflowing runoff of the Greater Lyon.