Median Vienna Flood Prevention Plan (PPRI) isocote lines, Chauvigny — Cenon-sur-Vienne section

The isocote lines (level curves of elevations reached by water during the centennial flooding) are a set of spatial data produced as part of the Mid Vienna Flood Risk Prevention Plan. Isocotes are reported on hazard maps and reference odds on regulatory maps. The reference rating is the isocote plus 20 cm. This reference rating is applied during certain developments. That is, at any point in the flooding zone defined on the hazard map, when a development is carried out, the rating for the development is the reference rating. This can be calculated at any point in the flood zone, by linear interpolation between the different isocote lines.