Prevention plan for the risk of differential terrain movements following drought and soil rehydration in the Val-de-Marne department — restricted area

Risk Prevention Plans (RPPs) are the key government instrument for risk prevention. Their objective is to control development in areas at risk. The development of a risk prevention plan generates a set of spatial data organised into several data sets. The same PPR may include spatial datasets containing: • main PPR encompassing perimeters (study perimeter, prescription perimeter, regulated scope); • restricted areas of the plan once approved. RPP regulations generally distinguish between ‘construction ban areas’, so-called ‘red areas’, where the hazard level is high and where the general rule is the construction ban; ‘areas subject to requirements’, known as ‘blue zones’ where the hazard level is medium and projects are subject to requirements adapted to the type of issue and areas not directly exposed to risks but subject to prohibitions or prescriptions; • hazard areas represented on the map of hazards used for risk analysis by crossing with the stakes, specifying for each zone the level of hazards to which it is exposed; • stakes (persons, property, activities, cultural or environmental heritage elements) threatened by a hazard and likely to be affected or damaged by it; • origins of risk, i.e. the real-world entity which, through its presence, represents a potential risk. This entity may be characterised by a name, a reference to an external object or a geographical object that locates the actual entity causing the risk.