Climate Change and Its Impact on Geological Formations in Coastal Areas

1. Introduction

Global climate change is a complex phenomenon that deeply affects natural systems and human life. One of the most obvious effects of this change is the changes in geological formations occurring in coastal areas. Coastal areas are dynamic ecosystems where land and sea interactions are intense, and these regions are extremely sensitive to the effects of climatic changes (Gerdes, Petzelberger, Scholz-Böttcher & Streif, 2003). When sea level rises or storm waves intensify, problems such as erosion, salt water floods and changes in the chemical structure of the soil can occur on the coasts (Haq, 1997). These problems threaten the continuity of both the natural balance and the human-made infrastructure.

Geological changes occurring in coastal areas lead to important environmental and economic consequences. In particular, sea level rise and storm waves increase coastal erosion and cause soil loss (Marzouk, Attia & Azab, 2021). This situation threatens both natural habitats and infrastructures in coastal areas. At the same time, saltwater intrusion on the coasts can pollute freshwater resources, jeopardizing agricultural productivity and the continuation of the ecological balance (Masciopinto & Liso, 2016). These problems directly affect both the quality of life of local people and economic activities.

The responses of coastal ecosystems to climate change depend on the dynamic structure of geological formations. Changes in sea level affect the movement and accumulation of sedimentary structures on the coasts, leading to a reshaping of the geological balance (Gerdes et al., 2003). This causes significant changes in the shape and size of coastlines. For example, studies conducted in the Baltic Sea region have shown that climate change accelerates coastal erosion and causes coastline regression (Łabuz, 2015). This poses a great risk to the future of coastal ecosystems and human settlements.

In addition, changes in coastal geological formations bring with them problems such as saltwater intrusion and groundwater pollution. Saltwater intrusion threatens both agricultural and drinking water resources by reducing the quality of freshwater resources (Masciopinto & Liso, 2016). This situation negatively affects regional economies and living conditions by reducing water availability.

Understanding the effects of climate change in coastal areas is of critical importance for the protection and continuous development of these areas. Modern technologies and approaches such as remote sensing and Geographic Information Systems (GIS) are effectively used in mapping and analyzing these effects (Marzouk et al., 2021). However, the results of these analyses also reveal the need for further research depending on future climate scenarios.

This article will examine the geological effects of climate change in coastal areas and evaluate the long-term consequences of these effects. The main objective of the study is to contribute to the development of strategies to reduce future risks by providing an understanding of these effects.

2. Coastal Erosion and Sea-Level Rise

2.1 Mechanisms of Coastal Erosion

Coastal erosion is a complex process that describes changes in the shape and structure of coastal areas. These changes usually occur under the influence of natural processes such as wind, wave movements, currents and sea level rise. Climate change accelerates these processes, disrupting the balance of coastal ecosystems and making coastal erosion more pronounced (Morales, 2022).

Sea level rise is one of the main factors triggering the erosion process on the coasts. In a study conducted by Rasmussen, Sonnenborg, Goncear and Hinsby (2013), it was stated that drainage channels and sea level increases lead to salt water intrusion and deterioration of coastal aquifers. This situation threatens the sustainability of both geological structures and ecosystems.

In addition, the increase in wave energy and the increase in storm frequency affect sediment transport on the coasts, leading to the disruption of the geological balance. The study by Kont, Jaagus and Aunap (2003) emphasizes that the rise in sea level on the Estonian coast accelerates coastal erosion and causes morphological changes. Especially low-lying coasts are more vulnerable to these changes.

2.2 Geological Transformations

Geological transformations in coastal areas are shaped by both natural processes and human effects. Sea level rise caused by climate change leads to radical changes in sediment accumulation and erosion processes. In the study conducted by Padmalal et al. (2014), changes in the morphodynamic structure of tropical coastal lagoons during the Holocene period were examined. In this study, how climatic fluctuations and sea level rise reshaped coastal morphology was discussed in detail.

Another important geological transformation observed in coastal ecosystems occurs when saltwater intrusion affects groundwater systems. In the study conducted by Ferguson and Gleeson (2012), it was shown that coastal aquifers are exposed to increased salinization due to both groundwater use and climate change. This situation threatens the sustainability of freshwater resources.

Delta areas, in particular, are among the regions most affected by sea level rise. The study conducted by Abija, Abam, Teme and Eze (2020) analyzed the effects of coastal erosion and sea level changes on coastal morphology in the Niger Delta. The research showed that changes in the coastline have significant impacts on agricultural areas and residential areas in the long term.

2.3 Case Studies

Many case studies have been conducted worldwide to demonstrate the effects of coastal erosion and sea level rise. These studies have shown that low-lying areas are particularly vulnerable and that these areas will undergo significant changes in the future.

Coastal Regions of Pakistan: A study conducted by Rabbani et al. (2008) on the coast of Pakistan indicated that sea level rise has caused major land losses in coastal areas. The study drew attention to the socio-economic impacts of these changes on local communities and emphasized the need to develop climate change adaptation strategies.

Coastal Regions of Morocco: A study conducted by Snoussi, Niazi, Khouakhi, and Raji (2010) on the coast of Morocco used Geographic Information Systems (GIS) to conduct coastal vulnerability analysis. The results revealed that coastal erosion poses a significant threat to urbanization and agricultural activities. This analysis shows how critical planning and management strategies are against climate change.

Niger Delta: A study conducted by Danladi, Kore and Gül (2017) on the coasts of Nigeria indicated that sea level rise and human activities have caused coastlines to recede. The study emphasizes the need to implement sustainable coastal management strategies to protect vulnerable areas in the region.

Mediterranean Coasts: A study conducted by Rizzetto (2020) on the coasts of the Mediterranean examined the effects of sea level rise and erosion on tourism activities. The study suggested engineering solutions and nature-based approaches to protect coastal tourism.

Coastal Lagoons of India: A study conducted by Ghorai and Sen (2015) on lagoons in India showed that climate change, combined with increased storm frequencies, threatens coastal ecologies. The study advocates the need for urgent policies to protect ecosystems.

These case studies reveal how vulnerable coastal areas are to climate change and how critical adaptation strategies play a role. Both engineering solutions and natural protection methods should be considered together to reduce coastal erosion caused by climate change.

3. Saltwater Intrusion and Soil Degradation

3.1 Processes Driving Saltwater Intrusion

Saltwater intrusion is the process of salting groundwater resources in coastal areas by mixing with seawater, and this situation is affected by both natural and human-induced factors (Rasmussen, Sonnenborg, Goncear & Hinsby, 2013). Factors such as climate change, sea level rise and excessive water use accelerate saltwater intrusion, threatening freshwater resources (Ferguson & Gleeson, 2012).

Sea Level Rise: Sea-level rise increases groundwater pressure, causing saltwater to move into freshwater aquifers. This accelerates salinization of coastal aquifers and reduces the quality of freshwater resources (Kont, Jaagus & Aunap, 2003). Sea level rise poses a great threat, especially for low-lying deltas and coastal areas.

Intensive Water Use: Excessive groundwater use in coastal areas reduces water pressure in aquifers, causing saltwater to infiltrate inland more easily (Morales, 2022). Irrigation activities, especially for agricultural and industrial purposes, accelerate this process. Ferguson and Gleeson (2012) showed that intensive groundwater use increases saltwater intrusion in coastal areas and this disrupts ecological balances.

Storm and Flood Events: Increasing storm frequency and intensity with climate change cause sudden saltwater inflow to coastal areas (Harley et al., 2006). Storm waves carry seawater inland, causing salinization of agricultural areas and deterioration of soil structural properties.

Drainage Canals and Infrastructure Developments: Man-made drainage canals and infrastructure projects can facilitate the transportation of saltwater to inland areas (Rasmussen et al., 2013). Canals, especially used in agricultural and irrigation systems, create pathways that allow saltwater to infiltrate inland areas.

3.2 Impact on Geological and Soil Composition

Saltwater intrusion is a process that directly affects both the quality of groundwater systems and soil structure. The mixing of seawater into groundwater changes the chemical composition of soils, reducing productivity and disrupting the balance of ecosystems (Padmalal et al., 2014).

Chemical Deterioration: The interaction of saltwater with the soil triggers ion exchange processes and leads to salt accumulation in the soil structure. This causes the dispersion of clay minerals and the decrease in soil permeability (Masciopinto & Liso, 2016). Salt accumulation makes it difficult for plant roots to absorb water, reducing agricultural productivity.

Physical Deterioration: The penetration of saltwater into the soil causes soil particles to stick together and the soil to harden (Snoussi et al., 2010). This hardening reduces the water retention capacity of the soil and negatively affects plant growth. In addition, the emergence of salt water on the surface with floods leads to the washing of the upper soil layer and loss of organic matter (Danladi, Kore & Gül, 2017).

Changes in Groundwater Aquifers: The effect of salt water intrusion changes the chemical composition of aquifers and reduces the drinkability of freshwater resources (Ferguson & Gleeson, 2012). Especially in coastal areas, aquifers undergo chemical degradation that is difficult to reverse due to intensive groundwater use and the effect of drainage channels.

Ecological Deterioration: Salt water intrusion can reduce the biodiversity in coastal ecosystems and cause the destruction of vegetation. Ghorai and Sen (2015) emphasize that salt water poses a significant threat to flora and fauna in areas with high ecological sensitivity.

3.3 Regional Examples

Studies conducted in different regions to reveal the effects of saltwater intrusion show that the problem is a global threat.

Niger Delta, Nigeria: Studies conducted by Abija, Abam, Teme, and Eze (2020) determined that the Niger Delta is extremely vulnerable to sea level rise and saltwater intrusion. The study shows that groundwater in this region is rapidly becoming saline and that there are serious losses in agricultural production.

Pakistan Coast: Rabbani et al. (2008) stated that saltwater intrusion has increased with sea level rise in the coastal areas of Pakistan. This situation threatens both freshwater resources and complicates the supply of agricultural and drinking water.

Moroccan Coast: In the study conducted by Snoussi et al. (2010), saltwater intrusion was mapped using GIS on the Moroccan coast. The study revealed that there is a significant decrease in the quality of water resources in the coastal areas and that this situation will worsen in the future.

Mediterranean Coast: Rizzetto (2020) examined the effects of sea level rise and salt water intrusion on the tourism sector in the Mediterranean coast. The study showed that the deterioration of soil quality in coastal areas damages tourism infrastructure and leads to economic losses.

Coastal Lagoons of India: Padmalal et al. (2014) determined that coastal lagoons in India have been vulnerable to salt water intrusion since the Holocene, altering morphodynamic processes.

Coastal Estonia: Kont, Jaagus, and Aunap (2003) showed that sea level rise and salt water intrusion on the Estonian coast lead to long-term deterioration of groundwater reserves.

These examples show how salt water intrusion poses a threat to coastal areas on a global scale. Developing strategies to combat and adapt to climate change will play a critical role in reducing the impacts of these problems.

4. Coastal Stability and Geohazards

4.1 Increased Geohazard Risks

Climate change threatens stability by increasing the frequency and severity of geological hazards in coastal areas. Geological events such as sea level rise, storm waves, erosion, landslides and liquefaction put coastal ecosystems and human settlements at risk (Harley et al., 2006). In particular, the acceleration of coastal erosion causes the coastline to recede and ecosystems to be destroyed (Morales, 2022).

Storms and Hurricanes: Global warming increases the frequency of extreme weather events such as storms and hurricanes and further magnifies geological hazards in coastal areas (Rabbani et al., 2008). Storm waves accelerate coastal erosion, leading to soil loss and threatening infrastructure.

Landslides and Landslides: Sea level rise and changes in precipitation patterns increase the risk of landslides in coastal areas by increasing ground saturation (Kont, Jaagus & Aunap, 2003). Especially on shores covered with loose sedimentary materials, the decrease in ground stability causes major problems.

Liquefaction: The liquefaction of saturated soils on shores during earthquakes can cause the collapse of structures (Ferguson & Gleeson, 2012). This situation becomes more evident especially in coastal areas at risk of earthquakes.

Threats to Coastal Dams and Infrastructure: Coastal protection structures may lose their functionality due to climate change and sea level rise (Snoussi et al., 2010). Barriers and breakwaters built for protection purposes may be inadequate against rising sea levels and storm waves.

4.2 Geological Instability and Structural Damage

Geological instabilities in coastal areas cause serious damage to both natural and man-made structures. While sea level rise weakens the geological stability of the coast, this accelerates events such as erosion and subsidence (Padmalal et al., 2014).

Landslides and Subsidence: Rising sea levels also increase groundwater levels, reducing ground stability. This situation causes landslides and ground subsidence, especially in densely populated areas (Danladi, Kore & Gül, 2017).

Damage to Infrastructure: Infrastructures such as bridges, roads, ports and water drainage systems are directly affected by coastal instabilities. Marzouk and Azab (2024) conducted a risk analysis of coastal areas using GIS and AHP models and revealed the potential hazards to which the infrastructure is exposed. In particular, the collapse of drainage systems increases floods and inundations, causing greater economic losses.

Weakening of Building Foundations: Soil salinization and flooding caused by saltwater intrusion on the coasts weaken building foundations and cause structural damage (Masciopinto & Liso, 2016). This accelerates corrosion, especially on reinforced concrete structures, shortening their lifespan.

Collapse of Ecosystems: The decline of coastal vegetation and soil erosion cause the balance in ecological systems to be disrupted (Ghorai & Sen, 2015). These disruptions affect agriculture and water resources, resulting in both economic and social consequences.

4.3 Risk Management and Adaptation Strategies

Both engineering solutions and nature-based strategies have been developed to reduce the impacts of climate change on coastal areas. These strategies aim to increase the resilience of coastal areas and provide long-term protection (Rizzetto, 2020).

Engineering Solutions:

·       Breakwaters and Seawalls: Breakwaters and seawalls are built to protect the coastline from storm waves. These structures prevent coastal erosion by reducing wave energy (Snoussi et al., 2010). However, such solutions are costly and limited in terms of sustainability.

·       Groundwater Control Systems: Drainage systems that regulate groundwater levels are being developed to control saltwater intrusion (Rasmussen et al., 2013).

·       Artificial Beach Recharges: The natural structure of the coast is strengthened by adding materials such as sand and gravel (Morales, 2022).

·       Nature-Based Solutions:

·       Mangrove and Plant Restoration: Planting mangroves and other plant species in coastal areas reduces erosion and creates a natural barrier (Harley et al., 2006).

·       Protection of Wetlands: Wetlands absorb water in coastal areas, preventing floods and maintaining ecological balance (Padmalal et al., 2014).

·       Adaptation and Planning Strategies:

·       GIS and Remote Sensing Technologies: GIS-based analyses developed by Marzouk and Azab (2024) are used to determine risks in coastal areas. These systems enable the implementation of effective planning and management strategies.

·       Risk Mapping: Mapping of hazard zones is an important tool for early warning systems and emergency planning (Danladi, Kore & Gül, 2017).

·       Settlement Planning and Regulations: Construction should be limited in coastal areas and settlement plans should be rearranged in risky areas (Rizzetto, 2020).

Coastal stability and geohazards are critical issues in the context of climate change. Natural threats such as sea level rise, storms and landslides threaten coastal ecosystems and human infrastructure. Effective implementation of risk management and adaptation strategies are vital to minimizing these threats.

4. Discussion and Conclusion

Climate change has significant and mostly irreversible effects on geological formations in coastal areas. In this article, how climate change affects coastal ecosystems and their structural balance is discussed in detail through mechanisms and regional examples. In the study, basic problems such as coastal erosion, sea level rise, salt water intrusion and geological instability are examined and the long-term effects of these problems are discussed.

The geological and ecological structures of coastal areas are rapidly changing due to direct effects such as sea level rise and storm waves (Harley et al., 2006). Erosion causes the retreat of shorelines, soil erosion and habitat loss, threatening both natural ecosystems and human settlements (Rasmussen et al., 2013). Especially low-lying coasts are among the areas most affected by these changes and face serious economic, agricultural and social risks (Kont, Jaagus & Aunap, 2003).

Saltwater intrusion is another critical problem that threatens freshwater resources in coastal areas. Due to sea level rise and human activities, salinization rates in freshwater aquifers are increasing, which negatively affects agricultural production, drinking water resources and ecosystem health (Ferguson & Gleeson, 2012). This problem has been observed to be more pronounced in sensitive ecosystems such as deltas, low-lying coasts and lagoons (Padmalal et al., 2014).

Geological instability and increasing geohazards in coastal areas are among the other important issues highlighted in the article. Events such as storm surges, landslides, liquefaction and infrastructure collapse cause long-term damage to coastal ecosystems (Danladi, Kore & Gül, 2017). Rising sea levels and erosion weaken the resilience of coastal infrastructure, causing serious economic losses (Marzouk & Azab, 2024). These effects threaten the sustainability of coastal areas and complicate social adaptation.

4.1. The Importance of Adaptation and Management Strategies

The article also discussed the adaptation and management strategies that need to be developed against these problems experienced in coastal areas. Engineering solutions, strengthening of natural barriers, and methods such as GIS-based risk mapping stand out as effective strategies for protecting coastal areas (Snoussi et al., 2010). In addition, nature-based solutions such as protecting wetlands and mangrove ecosystems provide long-term protection by supporting ecological sustainability (Harley et al., 2006).

Modern technologies and remote sensing systems provide an important tool for monitoring changes in coastal areas and determining risks in advance (Marzouk & Azab, 2024). These approaches play a critical role in developing early warning systems that will help reduce future risks.

Policies and Future Perspectives

Not only technical solutions but also strong policies and legal regulations are required for the protection of coastal areas. Regional planning should be supported by construction restrictions and environmental regulations in coastal areas (Rizzetto, 2020). International cooperation and the participation of local communities should also be encouraged to adapt to climate change.

Future research will play a critical role in better understanding changes in coastal areas and developing long-term conservation strategies. Modeling studies and regional analyses, especially based on climate scenarios, will provide the necessary scientific basis to increase the effectiveness of management strategies (Padmalal et al., 2014).

4.2. General Assessment

In conclusion, climate change has profound effects on coastal areas and a comprehensive approach is needed to manage these effects. Processes such as sea level rise, salt water intrusion, soil degradation and geological instability threaten the ecological and economic balance of coastal areas (Rasmussen et al., 2013).

In this article, the risks that coastal areas are exposed to are examined in the light of scientific studies and the measures that can be taken against these risks are discussed. In the future, the use of both engineering solutions and nature-based approaches together will provide an effective roadmap for the protection of coastal areas. At the same time, it is of great importance for societies and decision-makers to act together to adapt to climate change.

The protection of coastal areas is of vital importance not only in terms of environmental sustainability but also for ensuring social and economic stability. In this context, future research and applications will make significant contributions to minimizing the effects of climate change on coasts and creating more resilient coastal ecosystems.

Author Contributions: 

Conceptualization, M.M.; Methodology, M.M.; Resources, M.M.; Data Curation, M.M.; Writing – Original Draft Preparation, M.M.; Writing – Review & Editing, M.M.

Funding: This research received no external funding

Conflicts of Interest: The authors declare no conflict of interest.

Informed Consent Statement/Ethics approval: Not applicable.