coastaldefence

Coastal defence is the protection of coastlines from natural hazards such as erosion, flooding, and storm surge, as well as from military threats. It encompasses civil engineering approaches to reduce damage and preserve land, infrastructure, and ecosystems, and, in historical and contemporary contexts, elements of military defense to deter or delay incursions by sea.

Civilian coastal defence measures include structural works such as seawalls, revetments, groynes, breakwaters, and dune stabilization; sediment management through beach nourishment and managed retreat; river and stormwater drainage improvements; and land-use planning to limit development in high-risk areas. Early warning systems, evacuation planning, and habitat restoration are integrated into resilience strategies. Environmental impacts are assessed to balance protection with coastal dynamics and ecological value.

Military coastal defence refers to measures designed to protect harbors and shorelines from naval attack, including coast artillery batteries, minefields, anti-landing obstacles, underwater obstacles, harbour defenses, and modern sensors and defense systems. Historically, coastal fortifications such as the Atlantic Wall and other national shore defenses played major roles in warfare, while contemporary programs emphasize sensor networks, rapid-reaction forces, and joint operations with civilian authorities.

Coastal defence planning faces challenges of cost, maintenance, and environmental impact, and must account for climate change, sea-level rise, and changing risk profiles. Successful programs often employ integrated strategies that combine protection, risk management, and adaptive planning within legal and institutional frameworks.