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The climates of wave-related nearshore processes important to coastal erosion have been investigated based on analyses of wave data measured at six sites along the Mediterranean coast of Egypt, spanning 0.92 to 5.25 years. Wave climates along this 900-km coastline are nearly identical in their significant wave heights, periods, and directions. The evaluated nearshore processes that depend on combinations of deep-water wave heights and periods are found to respond to seasonal changes in wave conditions. These processes include the climates of breaker heights on beaches, beach face slopes, the morphodynamic classification of beaches, swash runup elevations induced by storm waves, the depth of closure of beach profiles, and calculated sediment transport rates. The seasonal changes observed in the wave-related nearshore processes are ultimately responsible for the episodic morphologic changes identified in the beach and seabed environments of the Nile Delta. The largest storm waves measured during the study period had deep-water significant wave heights of 7.7 and 6.8 m at the Dabba and Abu Qir coastlines, respectively. [ABSTRACT FROM AUTHOR]

In SW Spain, numerous tourist beaches have been nourished over recent years to counteract coastal retreat. Nourishment projects have not produced great endurance, mainly because of the lack of basic information on coastal dynamics and longshore sediment transport paths. In order to cover these aspects in a sandy coastal sector south of the Guadalquivir River mouth, a beach monitoring program was carried out between 1996 and 1998, with a secondary program between 2000 and 2002. Four main beach types were identified, each one with different volumetric trends during the monitoring periods. Most beaches recorded accretion because of the prevalence of fair weather conditions, which emphasized differences among beaches. In a broad sense, beaches located on intertidal rock platforms recorded erosion or no change. Those located updrift of rock platforms or human-made constructions (groins) recorded accretion. These structures divide the coast into several littoral cells, which control longshore sediment transport between beaches. All this information is very useful for planning replenishment projects on eroding beaches. The distribution of ceils, the sediment transport paths associated with them, and the volumetric trends obtained for every beach type were used for evaluating nourishment procedures, sand volume needs, and expected life time of the resulting artificial beaches. [ABSTRACT FROM AUTHOR]

Analyses have been undertaken of 68 beach-nearshore profiles spanning the years 1971–1995 to interpret sub-littoral cells of the Nile Delta that developed during cross-shore and alongshore sediment transport. Bottom sediments of these profiles taken along the 240-km length of the delta coastline have been analyzed to determine seabed level changes, textural and heavy mineral concentration distributions. The spatial distribution of seabed depth changes linked with the heavy mineral concentration allows identification of three zones of erosion (source areas) associated with accretion (sink areas). Erosion zones occur off the Nile promontories at Rosetta (−20 to −50 cm/yr), Burullus and Damietta (0 to −20 cm/yr). Accretion ranging from 0 to 40 cm/yr occurs between erosion zones at Abu Quir Bay, the Rosetta saddle, Gamasa embayments and along the western side of the jetty at the Suez Canal entrance, Port Said. This pattern was generally induced from the temporal variability in the direction and intensity of the incoming waves, currents, orientation of coastline, seafloor morphology and local protective structures. The correspondence among patterns of seabed depth change, heavy mineral concentration, and to some extent the texture of seabed sediments refine boundaries of littoral sub-cells of the Nile including sediment paths, sources, sinks, nodal points and zones of sediment transport convergence and divergence. This correspondence is not strongly correlated, as might be expected in this deltaic system where sediment has been recycled between recent and relict seabed settings moving in the alongshore and cross-shore directions. Nevertheless, the present investigation shows that the relationship between seabed level changes, heavy mineral concentration and to some extent mean grain size of the littoral zone can be practically applied in other deltaic settings to interpret sediment transport pathways particularly where there are less relict sediments. [Copyright &y& Elsevier]