Les risques naturels littoraux dans le Nord-Pas-de-Calais, France

Abstract

The coast of the Nord-Pas-de-Calais region largely consists of wide sandy beaches and coastal dunes, locally interrupted by estuaries, coastal settlements and some rocky cliffs. Similarly to most low-elevated coastlines, some of the unconsolidated shorelines of the Nord-Pas-de-Calais experience coastal erosion and marine flooding, with some coastal dunes undergoing erosion and coastline retreat since several decades. The coastal dunes often represent a natural barrier protecting the low-lying reclaimed land of the coastal plain from the sea and their erosion increases the risks of flooding during storm events. Because the coastal zone of the Nord-Pas-de-Calais region is densely populated, coastal retreat and marine flooding represent natural hazards threatening the costal populations in several areas along the shore. The potential impacts of storms are limited, however, due to the macrotidal regime (tidal range > 4 m) in the coastal zone of the region, which restricts the length of time during which coastal erosion and marine flooding can occur at high tide. In spite of this, the recent rise in sea level observed from tide gauge data stations in close proximity suggests that the risk of coastal erosion and marine flooding may increase during the next decades in this region.

Keywords

• France
• coastal erosion
• marine flooding
• storm surge
• Nord-Pas-de-Calais
• coastal hazards