In the context of management of natural disasters it is necessary for the public and the private sector to be aware of the status of all the information at different levels and to build pertinent indicators for the decision making process. The indicators can be built by combining different types of data: descriptive data, numerical data and geographical data. In order to have an overview of the system the exploration of the indicators through various levels would be interesting: - visualisation through geographical levels: national, provincial, departmental, communal and cadastral; - visualisation through temporal levels: analyzed periods; - visualisation through thematic levels: prevention themes, hazard themes, exposure themes. In order to navigate through all this information, a flexible structure must be implemented to store all the pre-calculated indicators and to make it easily accessible for reporting (graphics, charts, maps, tables). Dimensional modelling can help in the decision making process by exploiting urban data and risk data. This paper gives an overview of the evaluation of the pertinence of dimensional modelling to help deciders to get better insight on the data relative to natural disasters in France.