1.1 Introduction
Coastal flooding refers to the inundation of land areas along coastlines due to the rise in sea level or extreme weather events. In the context of Lekki, Lagos State, Nigeria, this phenomenon has become increasingly prevalent, posing significant challenges to both human settlements and marine ecosystems. The primary drivers of coastal flooding in Lekki are anthropogenic in nature, stemming from human activities that alter the natural environment. Urbanization, characterized by rapid infrastructural development and population growth, has led to increased impervious surfaces, reducing the land's ability to absorb rainfall and increasing surface runoff. Additionally, the reclamation of land for development purposes has disrupted natural water flow patterns, exacerbating flood risks. Deforestation and the destruction of wetlands further diminish the natural barriers that protect coastal areas from flooding.
As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the Aim and Objectives of the study. Others are Significance of the study, Scope of work, Research hypothesis and questions, Limitation of the study and Definition of terms.
1.2 Background of the Study
Coastal flooding has been a recurrent environmental issue in Nigeria, with historical records indicating its prevalence along the Lagos coastline for several decades. According to Ndimele (2024), communities in Lagos State, including Lekki, have experienced seasonal flooding events that have progressively worsened due to human interventions in the natural landscape. Early studies reported that natural processes such as tidal surges and heavy rainfall were primary contributors to coastal inundation; however, over time, anthropogenic activities have increasingly become central drivers.
Adewale et al. (2024) asserted that human activities, particularly urban expansion, industrial development, and sand mining, have significantly accelerated the occurrence and severity of flooding in coastal areas. These activities have modified natural drainage patterns and eroded protective shorelines, leading to heightened vulnerability of both residential and ecological zones. Oloyede (2022) stated that the destruction of mangroves and wetlands, which historically served as natural buffers against flooding, has exacerbated the problem, reducing the capacity of the environment to absorb and mitigate floodwaters (Oloyede, 2022).
Omosanya (2025) contended that increased sedimentation, pollution, and habitat loss resulting from flooding events have historically stressed aquatic ecosystems, contributing to the decline of key marine species over time. Roa (2022) affirmed that the combination of urbanization, industrial effluents, and climate variability has progressively altered the composition and abundance of marine life along the Lekki coastline (Roa, 2022). Coastal flooding is increasingly recognized as a major environmental challenge in Nigeria, particularly in rapidly urbanizing areas such as Lekki, Lagos State. According to Ndimele (2024), coastal flooding is largely driven by human activities that interfere with natural water flow and drainage systems. Rapid urban expansion and unplanned construction are reported to exacerbate surface runoff and increase the vulnerability of low-lying coastal areas to flooding.
Adewale et al. (2024) asserted that sand mining and land reclamation along the Lekki coastline have significantly altered natural shorelines, reducing the capacity of natural barriers to absorb floodwaters. Similarly, Oloyede (2022) stated that the destruction of mangroves and wetlands, which serve as crucial flood buffers, has intensified the frequency and severity of coastal floods. Roa (2022) affirmed that these human-induced changes not only affect the physical landscape but also disrupt local hydrology, making communities more susceptible to seasonal and extreme flooding events.
Omosanya (2025) contended that the influx of pollutants, including oil residues, heavy metals, and agricultural runoff, into aquatic ecosystems during floods leads to water quality degradation and habitat destruction. This disruption adversely affects marine species' reproductive cycles and results in population declines of economically and ecologically important organisms, such as fish and mollusks, which local communities rely upon for livelihood and food security. This study is set against the backdrop of these challenges, aiming to investigate the anthropogenic drivers of coastal flooding in Lekki, Lagos State, and assess their impact on marine biodiversity.
1.3 Statement of Problems
Investigation revealed that coastal flooding in Lekki, Lagos State, Nigeria, has escalated in recent decades, largely due to anthropogenic activities. Rapid urbanization, unregulated construction, and land reclamation have significantly altered natural drainage systems, leading to increased surface runoff and reduced water absorption capacity. Additionally, the extraction of sand for construction purposes has exacerbated coastal erosion, further diminishing the natural barriers that protect the coastline.
Furthermore, the impacts of coastal flooding extend beyond infrastructural damage. Marine biodiversity in the area faces significant threats as floodwaters often carry pollutants, including oil, heavy metals, and agricultural runoff, into aquatic ecosystems. The combined effects of pollution and habitat destruction have resulted in a decline in fish populations, which are vital for the local economy and food security. It is against this backdrop that this study seeks to investigate the anthropogenic drivers of coastal flooding in Lekki, Lagos State, and assess their impact on marine biodiversity.
1.4 Aim and Objectives of the Study
The aim of the study is to investigate the effects of human-induced activities on coastal flooding and their subsequent impact on marine biodiversity in Lekki, Lagos State.
The specific objectives of this study include:
- To evaluate the relationship between human activities and the degradation of aquatic ecosystems.
- To identify the major anthropogenic drivers of coastal flooding in Lekki, Lagos State.
- To examine the effects of coastal flooding on marine biodiversity in the study area.
- To provide recommendations for sustainable coastal management and biodiversity conservation.
1.5 Research Questions
Based on the stated objectives, the study will address the following research questions:
- What are the primary anthropogenic drivers of coastal flooding in Lekki, Lagos State?
- How does coastal flooding affect marine biodiversity in the area?
- What is the relationship between human activities and the degradation of aquatic ecosystems in Lekki?
- What measures can be implemented to mitigate the impacts of coastal flooding on marine life?
1.6 Significance of the Study
It is believed that at the completion of the study, the findings will inform policy and decision-making processes for sustainable coastal management. In addition, this research will support environmental agencies and non-governmental organizations in formulating effective conservation strategies.
Furthermore, the study will inform local communities about the importance of sustainable practices, such as proper waste management, mangrove preservation, and responsible urban development, which will help mitigate the adverse effects of coastal flooding on both livelihoods and ecosystems.
Lastly, the research will serve as a reference for future studies on coastal flooding and environmental management in other rapidly urbanizing coastal areas of Nigeria. The outcomes of this study will also enhance academic knowledge, guide practical interventions, and support the implementation of policies that will promote the resilience of both human and ecological systems in flood-prone regions.
1.7 Research Hypotheses
In order to pursue the objective of this study, the following generalized statements have been designed to guide and aids in obtaining the result for the experiment to be conducted. For this work, the null hypothesis will be represented with H0 while the alternative hypothesis will be represented with hypothesis H1.
Hypothesis One
- H0: There is no significant relationship between anthropogenic activities and coastal flooding in Lekki, Lagos State.
- H1: There is a significant relationship between anthropogenic activities and coastal flooding in Lekki, Lagos State.
Hypothesis Two
- H0: Anthropogenic activities do not significantly contribute to coastal flooding and negatively impact marine biodiversity in Lekki, Lagos State.
- H1: Anthropogenic activities significantly contribute to coastal flooding and negatively impact marine biodiversity in Lekki, Lagos State.
1.8 Scope of the Study
The scope of this research is focused on assessing the human-induced causes of coastal flooding and their effects on marine biodiversity in Lekki, Lagos State. Data will be collected from relevant organizations, government reports, and local communities.
1.9 Limitations of the Study
A study of this nature is bound to experience certain problems as such the constraints imposed on the research include:
- Time Constraints: A study of this nature needs relatively long time during which information for accurate or at least near accurate inference could be drawn. The period of the study was short, time posed as constraints to the research.
- Financial Constraints: The research would have extended the survey to other area at the empirical level, but limitation as included cost of transportation to the source of material and the cost of time setting of the already completed work.
- Lack of Cooperation: Many of the respondents are usually aggressive on issue that border cooperation among the respondents border.
- Response Bias: The study will involve surveys and interviews with cooperative managers and members. Response bias may occur if respondents provide socially desirable answers or if there is reluctance to disclose negative financial information due to privacy concerns or fear of repercussions.
1.10 Definition of Terms
Anthropogenic Drivers:
Human activities, such as urbanization, industrialization, and land reclamation, that alter natural environments and influence environmental hazards (Adewale et al., 2024).
Coastal Flooding:
The inundation of coastal land areas caused by sea-level rise, storm surges, heavy rainfall, and human activities that impede natural drainage (Ndimele, 2024).
Marine Biodiversity:
The variety of life forms within marine ecosystems, including fish, mollusks, crustaceans, mangroves, and other aquatic organisms (Oloyede, 2022).
Land Reclamation:
The process of creating new land from oceans, riverbeds, or wetlands for development purposes, often contributing to environmental disruption (Omosanya, 2025).
Sand Mining:
The extraction of sand from coastal or riverine areas, which reduces natural coastal protection and can exacerbate erosion and flooding (Roa, 2022).
Sustainable Coastal Management:
Strategic planning and actions aimed at balancing human development and environmental protection to maintain resilient coastal ecosystems (Omosanya, 2025).
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