Impact of Sand Dredging on Areas Close to Bridges (A Case Study of Gbaji Badagry-seme Expressway Blg, Lagos State)
Chapter One
Objective of the study
- Evaluate the specific effects of sand dredging activities on the structural integrity and stability of bridges.
- Investigate the environmental consequences of sand dredging near bridges.
- Analyze how sand dredging activities influence the hydraulic characteristics of rivers and streams surrounding bridges.
CHAPTER TWO
REVIEWED OF RELATED LITERATURE
DREDGING
“Dredging is a process used to remove sediment, debris, or other materials from the bottom of water bodies such as rivers, lakes, and harbors. It serves various purposes ranging from maintaining navigable waterways to environmental remediation and land reclamation.”
One significant application of dredging is in maintaining navigation channels and ports. As noted by a report by the U.S. Army Corps of Engineers, dredging plays a crucial role in ensuring that waterways remain deep enough for ships to navigate safely and efficiently (USACE, 2020).
In addition to navigation, dredging is often employed in environmental cleanup efforts. For instance, in polluted water bodies, dredging can remove contaminated sediment, thereby improving water quality and restoring aquatic habitats. A study by Bilkovic et al. (2018) discusses the use of dredging as a method to remediate contaminated sediments in aquatic environments.
Furthermore, dredging is utilized in land reclamation projects, where areas of land are created or restored from bodies of water. This process has been extensively used in coastal regions for urban development and infrastructure expansion. For instance, the Netherlands, a country renowned for its expertise in water management, has employed dredging extensively in reclaiming land from the sea (van Koppen et al., 2019).
However, dredging activities can also have significant environmental impacts. The removal of sediment can disrupt ecosystems, harm aquatic life, and alter water flow patterns. To mitigate these impacts, environmental assessments and regulations are often implemented to ensure dredging activities are conducted sustainably and with minimal harm to the environment (Lu et al., 2021).
Dredging is a versatile process with various applications, from maintaining navigable waterways to environmental remediation and land reclamation. While it is essential for economic development and environmental restoration, careful planning and regulation are necessary to minimize its adverse effects on ecosystems and aquatic habitats.
CHAPTER THREE
RESEARCH METHODOLOGY
INTRODUCTION
In this chapter, we described the research procedure for this study. A research methodology is a research process adopted or employed to systematically and scientifically present the results of a study to the research audience viz. a vis, the study beneficiaries.
RESEARCH DESIGN
Research designs are perceived to be an overall strategy adopted by the researcher whereby different components of the study are integrated in a logical manner to effectively address a research problem. In this study, the researcher employed the survey research design. This is due to the nature of the study whereby the opinion and views of people are sampled. According to Singleton & Straits, (2009), Survey research can use quantitative research strategies (e.g., using questionnaires with numerically rated items), qualitative research strategies (e.g., using open-ended questions), or both strategies (i.e., mixed methods). As it is often used to describe and explore human behaviour, surveys are therefore frequently used in social and psychological research.
POPULATION OF THE STUDY
According to Udoyen (2019), a study population is a group of elements or individuals as the case may be, who share similar characteristics. These similar features can include location, gender, age, sex or specific interest. The emphasis on study population is that it constitutes of individuals or elements that are homogeneous in description.
This study was carried to examine mpact of sand dredging on areas in close proximity to bridges. Gbaji Badagry-Seme Expressway BLG, Lagos State form the population of the study.
CHAPTER FOUR
DATA PRESENTATION AND ANALYSIS
INTRODUCTION
This chapter presents the analysis of data derived through the questionnaire and key informant interview administered on the respondents in the study area. The analysis and interpretation were derived from the findings of the study. The data analysis depicts the simple frequency and percentage of the respondents as well as interpretation of the information gathered. A total of eighty (80) questionnaires were administered to respondents of which only seventy-seven (77) were returned and validated. This was due to irregular, incomplete and inappropriate responses to some questionnaire. For this study a total of 77 was validated for the analysis.
CHAPTER FIVE
SUMMARY, CONCLUSION AND RECOMMENDATION
Introduction
It is important to ascertain that the objective of this study was to ascertain Impact of sand dredging on areas in close proximity to bridges ( A case study of Gbaji Badagry-Seme Expressway BLG, Lagos State). In the preceding chapter, the relevant data collected for this study were presented, critically analyzed and appropriate interpretation given. In this chapter, certain recommendations made which in the opinion of the researcher will be of benefits in addressing Impact of sand dredging on areas in close proximity to bridges
Summary
This study was on a Impact of sand dredging on areas in close proximity to bridges. Three objectives were raised which included: Evaluate the specific effects of sand dredging activities on the structural integrity and stability of bridges, investigate the environmental consequences of sand dredging near bridges and analyze how sand dredging activities influence the hydraulic characteristics of rivers and streams surrounding bridges. A total of 77 responses were received and validated from the enrolled participants where all respondents were drawn from Gbaji Badagry-Seme Expressway BLG, Lagos State. Hypothesis was tested using Chi-Square statistical tool (SPSS).
Conclusion
In conclusion, the study emphasizes the urgency of adopting integrated approaches to address the challenges posed by sand dredging near bridges, including improved regulatory frameworks, stakeholder engagement, and implementation of mitigation measures. By addressing the environmental and socio-economic dimensions of dredging impacts, policymakers, engineers, and stakeholders can work together to promote sustainable development and safeguard the integrity of bridge infrastructure and riverine ecosystems in Lagos State and beyond.
Recommendation
Based on the findings of the study on the impact of sand dredging on areas in close proximity to bridges along the Gbaji Badagry-Seme Expressway BLG in Lagos State, several recommendations can be proposed to mitigate the adverse effects of dredging activities and promote sustainable development:
- Strengthen regulations governing sand dredging operations near bridges, including permit requirements, environmental impact assessments, and monitoring protocols. Ensure strict enforcement of existing laws to prevent unauthorized dredging activities and mitigate potential environmental and socio-economic impacts.
- Establish buffer zones around bridge structures to limit dredging activities in close proximity to critical infrastructure. Define setback distances based on engineering considerations, environmental sensitivity, and safety requirements to minimize risks to bridge integrity and riverine ecosystems.
- Promote the adoption of best management practices for sand dredging operations, including sediment containment measures, sedimentation ponds, and sedimentation barriers. Encourage the use of environmentally friendly dredging techniques such as suction dredging to minimize habitat disturbance and sediment resuspension.
- Implement routine water quality monitoring programs to assess the impact of dredging activities on river ecosystems. Monitor key parameters such as turbidity, sediment concentration, nutrient levels, and contaminant concentrations to track changes over time and identify potential environmental risks.
- Foster collaboration and engagement among government agencies, local communities, industry stakeholders, and non-governmental organizations to address the complex challenges associated with sand dredging near bridges. Facilitate dialogue, knowledge sharing, and participatory decision-making processes to ensure inclusive and sustainable management of riverine resources.
References
- Gao, Y., et al. (2019). Environmental Impacts of Dredging Activities: A Review. Journal of Environmental Management, 231, 495-505.
- Kondolf, G.M., et al. (2008). Sustainable Sediment Management in Asian River Basins: Assessment of Six Asian Rivers. Environmental Management, 41(3), 336-355.
- Pillay, T.V.R., et al. (2019). Impacts of Dredging on the Water Quality and Benthic Macroinvertebrates in the uMngeni River Estuary, South Africa. Environmental Monitoring and Assessment, 191(3), 168. Frings, R.M., et al. (2018). The Ecological Effects of Suspended and Bedded Sediments on Fish: A Case Study in the Upper Rhine River. Ecological Engineering, 120, 532-543.
- Gao, Y., et al. (2019). Environmental Impacts of Dredging Activities: A Review. Journal of Environmental Management, 231, 495-505.
- Kondolf, G.M., et al. (2008). Sustainable Sediment Management in Asian River Basins: Assessment of Six Asian Rivers. Environmental Management, 41(3), 336-355. Brown, D., & Brown, D. (2003). Bridges: Three Thousand Years of Defying Nature. Harvard University Press.
