Contribution of the integrated topo‐bathymetric model for coastal wetland evolution: case of geomorphologic and biological evolution of Ichkeul Marshes (North Tunisia)
Apports du MNT topo-bathymétrique pour l'évolution bio-géomorphologique des marais d'Ichkeul (Tunisie)
Résumé
This chapter focuses on the reliability of remote sensing imagery combined with topographic and bathymetric data to map the coastal wetland communities in Ichkeul marshes. It combines both the object‐oriented classification of high spatial resolution imagery and the integrated topographic‐bathymetric digital terrain model (topo‐bathymetric DTM) in order to characterize and to map vegetation communities across Ichkeul marshes. The chapter settles the integrated topo‐bathymetric DTM by combining three datasets: the lake bathymetry, the marshes and the mountain digital topographies. It classifies Ichkeul marshes, the new topo‐bathymetric DTM is used with multispectral imagery from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images from the Terra satellite. In the chapter, classification rules for distinguishing vegetation communities are created automatically by using attributes (PCA1, topo‐bathymetric DTM and Normalized Vegetation Index (NDVI) value) of training segments. The first rule in the classification tree separates non‐vegetated and vegetated objects using the NDVI attribute.