InSAR Study of Shoreline Change along the Damietta Promontory, Egypt

Aly, M.H.; Giardino, J.R.; Klein, A.G., and Zebker, H.A., 2012. InSAR study of shoreline change along the Damietta Promontory, Egypt. Shoreline erosion has been a major problem in the Nile Delta since the full damming of the Nile River in 1970, especially along the two Nile promontories (Rosetta and Damietta). Synthetic aperture radar interferometric (InSAR) data acquired by the European remote-sensing satellites (ERS-1 and ERS-2), spanning 1993–2000, were utilized in this study to (1) identify the erosion/accretion pattern along the Damietta Promontory shoreline, (2) monitor the evolution of the accretionary spit on the E side of the promontory, and (3) investigate the effect of protective structures established in multiple stages since 1991. The tandem coherence of InSAR was found to be a powerful tool for delineating the water/land boundary with very high precision. Four locations along the promontory shoreline experienced substantial erosion, with average rates of −9, −39, −17, and −11 m yr−1. Local accretion occurred at the W and E flanks of the promontory, with average rates of 12 and 36 m yr−1, respectively. The sandy spit increased in width by about 36 m yr−1 and migrated laterally to the SE at an average rate of 120 m yr−1. Shoreline instability during 1993–2000 implies that the established defensive structures have not been sufficient to cease erosion completely. As the promontory shoreline has not been armored with further protection since 2000, the identified erosional locations at the promontory flanks still require protection and monitoring to help mitigate the impact of shoreline retreat and its environmental consequences.