Intertidal bathymetry and foreshore slopes derived from satellite images for static coasts

Abstract

The physical geography of the coastal areas of Bangladesh is highly diverse and dynamic. Despite its significance, getting reasonable estimates of the foreshore slopes is quite challenging for a large spatial scale along the coastline of Bangladesh. In this study, a method of estimating the slope from satellite-based shoreline positions in different times covering a tidal cycle is explained particularly for static coasts. The procedure is based on the shoreline elevations and their correlation with the temporal variation of the position of water within the intertidal zone. The methodology was tested against in-situ measurements with reasonably good agreement for a static coastal region. The proposed methodology does not demand any supplementary data other than satellite images and tidewater elevation for static coasts, and the result can produce intertidal bathymetry along with foreshore slopes without requiring any laborious and time-consuming field data collection. The technique can be used for developing intertidal models for monitoring the dynamics within intertidal regions, as well as morpho-dynamic modeling and also cartographic updates.