IMIS

The seven classes allowed us to analyse the spatial dynamics of specific sediment volumes. The technique made it possible to distinguish the sand used for berm replenishment works or for beach nourishments from the sand naturally found on the backshore and the foreshore. Subtracting sequential DTMs (digital terrain models) resulted in height difference maps indicating the erosion and accretion zones. The combination of both data types, hyperspectral data and LIDAR data, provides a powerful tool, suited to analyse the dynamics of sandy shorelines. The technique was demonstrated on three sites along the Belgian shoreline: Koksijde, located on the West Coast and characterized by wide accretional beaches, influenced by dry berm replenishment works and the construction of groins; Zeebrugge, on the Middle Coast, where a beach nourishment was executed one year before the acquisitions started and where the dams of the harbour of Zeebrugge are responsible for the formation of a large accretional beach, and Knokke-Heist, located on the East Coast and characterized by narrow, locally reflective, beaches, heavily influenced by nourishment activities. The methodology applied allowed retrieval of the main sediment transport directions as well as the amount of sediment transported. It proved to be specifically suited to follow up the redistribution and the re-sorting of the fill in beach nourishment areas [Source: Deronde, B.; Houthuys, R.; Henriet, J.-P.; Van Lancker, V. (2008). Monitoring of the sediment dynamics along a sandy shoreline by means of airborne hyperspectral remote sensing and LIDAR: a case study in Belgium. Earth Surf. Process. Landforms 33(2): 280-294; dx.doi.org/10.1002/esp.1545].