Journal of Coastal Zone Management

Coastal geomorphology is the scientific study of the origin, evolution and configuration of coastal landforms. It focuses on understanding the dynamic interactions between the ocean, atmosphere and land that shape the physical features of coastlines. This field integrates geology, oceanography, climatology and environmental science to analyze how natural processes and human activities influence coastal environments. Coastal geomorphology is essential for managing coastal zones, predicting changes, protecting habitats and mitigating hazards such as erosion, flooding and sea level rise.

The coast is a highly dynamic environment where the forces of wind, waves, tides and currents constantly interact with geological structures. These interactions create a variety of landforms such as beaches, cliffs, dunes, estuaries, spits, barrier islands and deltas. Understanding how these features develop and change over time is central to coastal geomorphology. The processes responsible for shaping coastlines can be broadly categorized into erosional, depositional and tectonic forces, each contributing uniquely to coastal morphology.

Erosional processes are those that remove material from the coast. Waves crashing against cliffs cause hydraulic action, where the force of water compresses air in cracks, eventually breaking rock apart. Abrasion occurs when sediment and rocks carried by waves grind against the shoreline, wearing it down. Attrition breaks down particles in the water into smaller, smoother pieces. Solution or corrosion refers to the chemical action of seawater dissolving soluble rocks like limestone. These erosional forces often create dramatic coastal features such as sea cliffs, wave-cut platforms, sea caves, arches and stacks.

Depositional processes involve the accumulation of sediments transported by waves, tides, rivers and wind. When the energy of these transporting agents decreases, sediments settle and build up coastal landforms. Beaches, made primarily of sand or gravel, are the most common depositional features. Other landforms like spits, barrier islands and deltas also result from sediment deposition. These features are vital for coastal protection, biodiversity and human activities such as recreation and fishing. The balance between erosion and deposition determines the shape and stability of shorelines.

Tectonic activity plays a significant role in coastal geomorphology, especially in regions where earthquakes, volcanic activity, or land uplift and subsidence occur. Tectonic uplift can raise former seabeds above water, creating elevated terraces and cliffs. Conversely, subsidence can cause coastal flooding and the drowning of landforms. Volcanic activity can build new landmasses, such as volcanic islands. These geological forces operate over longer timescales but dramatically influence the long-term evolution of coastlines.

Sea level changes are a critical factor in coastal geomorphology. During periods of glaciation, sea levels drop as water is locked in ice caps, exposing more land. When glaciers melt, sea levels rise, inundating coastal plains and reshaping shorelines. Current concerns about global warming and climate change focus on rising sea levels due to melting ice and thermal expansion of seawater. Rising sea levels threaten low-lying coastal areas, increase erosion rates and alter sediment deposition patterns. Coastal geomorphologists study these changes to predict future scenarios and inform adaptive management strategies.

Coastal geomorphology also examines the role of human activities on shoreline dynamics. Urbanization, construction of seawalls, groynes and jetties, dredging and sand mining alter natural sediment transport processes. These interventions can exacerbate erosion in some areas while causing sediment buildup in others, disrupting natural coastal equilibrium. Pollution and land reclamation further impact coastal habitats and geomorphological processes. Understanding these human influences is crucial for developing sustainable coastal management plans that minimize negative environmental consequences.

The study of coastal geomorphology employs various research methods. Field surveys, including sediment sampling and topographic measurements, provide direct observations of coastal features. Numerical models simulate coastal processes such as wave dynamics, sediment transport and shoreline change, helping to predict future evolution. These tools enable scientists to analyze complex interactions and support decision-making for coastal protection and development.

Coastal geomorphology has significant practical applications. It informs the design and placement of coastal infrastructure like ports, seawalls and breakwaters to ensure their stability and minimize environmental impact. It aids in identifying areas at risk of erosion or flooding, guiding land-use planning and disaster preparedness. Restoration projects for beaches, dunes and wetlands benefit from geomorphological insights to enhance ecosystem services and resilience. Additionally, coastal geomorphology contributes to heritage conservation by explaining the formation of natural landmarks and archaeological sites.

Understanding coastal geomorphology is increasingly important in the context of climate change and population growth. Coastal areas are home to billions of people worldwide and support critical economic activities. Rising sea levels, intensified storms and human pressures threaten these vulnerable zones. Geomorphological research helps identify potential hazards, develop mitigation measures and promote adaptation strategies that work with natural processes. This science underpins efforts to balance development needs with environmental protection, ensuring sustainable futures for coastal communities.