Influence of Coastal Measures on Shoreline Kinematics Along Damietta coast Using Geospatial Tools

Abstract

The shoreline trajectory of Damietta city, located at the Northern coast of Egypt, is dramatically subjected to significant kinematic changes. Several types of coastal measures have been applied substantially along the coastal stretch of Damietta to protect shoreline (detached breakwaters, Jetties, groins, and seawalls). This study focuses in the assessment of shoreline kinematics response due to the existence of these structures during the period from 1990 to 2015 using satellite images and geo-spatial tools. Three semi-automatic extraction techniques are initially tempted for Landsat ETM 2003 imagery namely; Iso cluster technique, threshold method, and onscreen digitizing. The shoreline variation measurement of is described for three sectors based on the allocation of the coastal measures:(1) the western sector encompassing Damietta port with two jetties; (2) the central sector including detached breakwaters; (3) the eastern portion of Damietta estuary passing through a seawall. The results show that, the shoreline has progressed by +10.0 m/year rate west of Damietta port. Behind the detached breakwaters, the shoreline has advanced by +12.0 m/year from 1999 to 2003 and then has decreased gradually to be near the stable state in 2015. The highly eroded by average rate of - 78 m/year appeared at end of eastern seawall.