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Sea Groynes
Context:
The coastal population in Ernakulam district of Kerala is once again up in arms over the ever-worsening issue of sea incursion. Hundreds of residents have laid siege to the Fort Kochi-Alappuzha coastal State Highway along the Kannamaly coast, disrupting traffic.
What is Sea Groynes?
- A groyne is a long, narrow structure built out into the sea from the beach to limit the movement and loss of beach material (sand and shingle).
- It is a shore protection structure built perpendicular to the shoreline of the coast (or river), over the beach and into the shoreface (the area between the nearshore region and the inner continental shelf). A form of hard engineering, they are easy to construct, have long-term durability and are low maintenance.
- It requires an adequate supply of sediment and medium to strong longshore sediment transport to be effective.
- It can be made of wood, steel, concrete, rubble mound, or sand-filled geobags.
- Its design (planform, length, height, cross-shore profile, inclination) influences its impact on shore morphology, which also depends on sea water level, wave climate, and sediment supply in the surf zone.
- It can be designed in various shapes, such as straight, bent, curved, L-shaped, T-shaped, or Y-shaped, depending on the specific coastal conditions and objectives.
- They are more effective when used in conjunction with other soft shore protection methods, such as artificial beach nourishment or shore nourishment.