Posted: December 24th, 2023

Investigating the Impact of Coastal Erosion at Coastal Communities

Investigating the Impact of Coastal Erosion at Coastal Communities

Coastal erosion is the removal of material from the coast by wave action, tidal currents, and/or human activities, resulting in a landward retreat of the coastline (Nehra, 2018). Coastal erosion can have significant impacts on coastal communities, affecting their economy, environment, and social well-being. This paper aims to investigate the causes, effects, and control strategies of coastal erosion at coastal communities around the world.

Causes of Coastal Erosion

The main cause of coastal erosion is wave action, which exerts pressure on the surrounding rock and erodes it through compression, abrasion, and attrition (Nehra, 2018). Wave action is influenced by the wind speed, fetch, and duration, as well as the shape and orientation of the coastline. The higher the wave energy, the higher the rate of erosion (National Research Council, 1990).

Another cause of coastal erosion is tidal currents, which transport sediment along the coast and create erosional or depositional features such as spits, bars, and deltas. Tidal currents are affected by the gravitational forces of the moon and the sun, as well as the shape and depth of the coastal basin (National Research Council, 1990).

Human activities can also contribute to coastal erosion by altering the natural balance of sediment supply and transport. Some examples of human-induced causes are:

– Construction of dams, reservoirs, and diversions that reduce the sediment input from rivers to the coast
– Sand mining from riverbeds or beaches that deplete the natural sediment sources
– Extraction of groundwater or hydrocarbons that cause subsidence or compaction of the coastal land
– Coastal development that modifies the natural shoreline or vegetation cover
– Construction of hard structures such as seawalls, groins, or breakwaters that interfere with the longshore sediment transport or reflect wave energy (National Research Council, 1990; Nehra, 2018).

Effects of Coastal Erosion

Coastal erosion can have negative effects on coastal communities in terms of economic, environmental, and social aspects. Some examples of these effects are:

– Loss of land and property due to cliff collapse or shoreline retreat
– Damage to infrastructure and facilities such as roads, bridges, pipelines, or power lines
– Reduction of tourism and recreation opportunities due to beach erosion or loss of scenic views
– Degradation of coastal ecosystems and habitats such as dunes, wetlands, or coral reefs
– Increased exposure to flooding and storm surges due to lower elevation or reduced natural protection
– Displacement of coastal populations and loss of cultural heritage due to erosion or inundation (National Research Council, 1990; Nehra, 2018).

Control Strategies for Coastal Erosion

There are various strategies to control or mitigate coastal erosion depending on the specific causes, effects, and objectives of each case. These strategies can be classified into two main categories: hard engineering and soft engineering.

Hard engineering involves the use of artificial structures to protect the coast from wave action or stabilize the shoreline. Some examples of hard engineering are:

– Seawalls: vertical walls built along the shore to prevent erosion or flooding by reflecting wave energy
– Groins: perpendicular structures built on the beach to trap sediment and prevent longshore transport
– Breakwaters: offshore structures built parallel to the shore to reduce wave energy and create a calm water zone
– Revetments: sloping structures built on the shore to absorb wave energy and protect the base of cliffs or dunes
– Gabions: wire cages filled with rocks placed on the shore to act as a buffer against wave action (Nehra, 2018).

Hard engineering has some advantages such as providing immediate protection, increasing safety, and creating recreational opportunities. However, hard engineering also has some disadvantages such as being expensive, requiring maintenance, disrupting natural processes, causing environmental impacts, and transferring erosion problems elsewhere (Nehra, 2018).

Soft engineering involves the use of natural or biological methods to enhance the natural resilience of the coast or restore its equilibrium. Some examples of soft engineering are:

– Beach nourishment: adding sand to eroded beaches to increase their width and height
– Dune restoration: planting vegetation or installing fences on dunes to stabilize them and prevent wind erosion
– Marsh creation: creating wetlands in low-lying areas to act as a buffer against wave action and provide habitat for wildlife
– Managed retreat: allowing the shoreline to move naturally landward by removing human interference or relocating structures
– Education and awareness: informing and involving stakeholders about the causes and effects of coastal erosion and promoting sustainable practices (Nehra, 2018).

Soft engineering has some advantages such as being cheaper, requiring less maintenance,