4.9 - Human Influence on Coastal Environments
Direct effects of human activities on coastlines
Human activities often have immediate and noticeable impacts on coastal landscapes. These direct effects occur as a result of specific actions taken by humans that alter the natural coastal environment in a straightforward manner.
Key direct impacts on coastlines
- Construction of protective structures - Building seawalls directly prevents erosion at the specific location where they are installed.
- Alteration of natural landscapes - Construction activities physically change the shape and structure of the coastline.
Indirect effects of human activities on coastlines
Beyond the immediate changes caused by human actions, there are secondary consequences that arise as a result of these direct interventions.
Key indirect consequences on coastlines
- Increased erosion in adjacent areas - Protective structures like seawalls in one location can redirect wave energy, leading to heightened erosion further along the coast.
- Wider coastal changes - Alterations in one part of the coastline can affect sediment transport and deposition patterns elsewhere.
Impacts of agriculture on coastal environments
Agricultural practices near coastal regions can significantly influence the stability and vulnerability of these landscapes.
Agricultural influences on coastal stability
- Low economic protection - Agricultural land near coasts often has lower economic value compared to urban areas, meaning it is frequently left unprotected from erosion or flooding.
- Vegetation as a stabiliser - Plants and vegetation on clifftops help bind soil together, reducing the risk of erosion.
- Clearing vegetation for crops - Converting grazing land to crop cultivation removes this protective vegetation, exposing soil to weathering processes.
- Land reclamation and drainage - Draining wetlands or reclaiming land for agriculture eliminates natural flood barriers.
Impacts of development on coastal areas
Coastal zones are often prime locations for human settlement and business activities. However, such development can profoundly affect the natural coastal environment.
Development effects on coastal landscapes
- Attraction for population and business - Coastal areas draw significant residential and commercial development.
- Increased coastal defences - Areas with large population centres typically have more protective structures.
- Positive protection outcomes - Development can enhance protection against erosion when investments are made in coastal defences.
- Indirect transport changes - Building on coastal lowlands can disrupt sediment supply to beaches.
- Reduced beach protection - Narrower beaches, resulting from restricted sediment supply, offer less natural defence against wave action.
Impacts of industry on coastal landscapes
Industrial activities along coastlines, while economically beneficial, often contribute to the degradation of natural protective features.
Industrial influences on coastal vulnerability
- Quarrying activities - Coastal quarries expose rock surfaces, making them more prone to weathering and erosion.
- Gravel extraction from beaches - Removing gravel and other materials from beaches reduces the natural barrier that protects cliffs, heightening erosion risks.
- Pressure on salt marshes from ports - Industrial development, particularly at ports, often encroaches on salt marshes, which are natural flood barriers.
- Loss of natural barriers - Building on or altering salt marshes diminishes their protective role.
The role of coastal management in mitigating erosion
Coastal management involves strategies and interventions aimed at protecting coastal landscapes from the damaging effects of erosion and other natural processes.
Strategies and effects of coastal management
- Focus on erosion prevention - Coastal management prioritises safeguarding landscapes from erosion impacts.
- Alteration of sediment movement - Management techniques can change how sediment is transported and deposited along the coast.
- Reduction of erosion through defences - Coastal defences effectively minimise erosion by preventing landscape changes and shoreline retreat.
- Potential for increased erosion - Some management strategies can reduce protective beach material, inadvertently increasing erosion risks.