Shoreline Changes and Mitigation Plans for Intelligent Cities with Emphasis on Environment-Friendly Solutions

Shoreline stabilization is one of the major challenges that may threaten the sustainability of intelligent coastal cities. Many new intelligent cities are being constructed or being upgraded along the reach between Al-Alamin and Sidi Abdel Rahman cities of Matrouh governorates in Egypt. Investigations have been for the shoreline stability in Sidi Abdel Rahman bay (SARB) before and after the construction of man-made structures while considering climate change and environmental impacts. In 2021, dramatic shoreline changes have been observed shortly after the construction of a large breakwater in the bay. This includes shoreline erosion of more than 30 m east of the breakwater and deposition of nearly 100 m west of it. Remote sensing data, field surveying data, and numerical simulation using MIKE 21 packages have been utilized to study the shoreline movement before and after the construction of the breakwater. Analysis of results has shown that the shoreline was almost stable before 2021 with slight seasonal and sometimes annual fluctuations, but the dramatic changes are caused by intercepting most of the sediment by the newly constructed breakwater. Several soft/hard mitigation measures have been proposed and examined using the numerical models including sand engine, short groin system, continuous sand nourishment, sand bypass, and submerged detached breakwater system. Comparisons have been held and summarized in this paper considering short and long-term impacts with emphasis on reliability and environmental impacts.