Coast Defenses

Definition

Hard or soft engineered structures, or combinations of these, designed to form effective coastal defense solutions.

Introduction

Coastal defenses are measures taken to protect coastlines from erosion and other damage or to prevent flooding caused by the combined effect of sea waves, extreme tides, and storm surge. They are designed to work by controlling wave action, coastal currents, and sediment movement on beaches. Each coastal defense method has its own advantages and disadvantages, which should be carefully studied and weighed before adopting one into a given site (Horikawa 1978).

Types of Coastal Defenses

There are two main types of coastal defenses: hard engineered structures and soft engineering solutions (Coastal Engineering Manual 2008). Often, hard structures are combined with soft engineering solutions to form effective coastal defense schemes. Hard structures can be seawalls, offshore breakwaters, and groynes. Most hard structures are constructed of concrete or...