ASSESSMENT OF FLOOD RISK MANAGEMENT STRATEGIES IN URBAN AREAS OF NIGERIA: A CASE STUDY OF 2024 FLOODING EVENT IN LAGOS STATE

CHAPTER ONE

INTRODUCTION

1.1 Background of the study

It is widely agreed upon that the occurrence of floods worldwide is altering significantly due to the growing frequency of heavy rainstorms and storm surges caused by climate change and rising sea levels (Dicke et al., 2022). In metropolitan settings, the expansion of impermeable surfaces worsens the intensity of flooding, thereby amplifying flood-related destruction. This highlights the focus on flood risk and its management, especially in densely populated metropolitan regions where people and important infrastructure are concentrated (Jha et al., 2019). Developing nations, despite their typically limited ability to adjust to climate change effects, are facing the challenge of effectively managing flood risks due to the rising frequency of flooding incidents. Effective flood risk management is crucial for metropolitan regions in emerging countries that are undergoing significant and swift transformations in terms of urbanisation, population expansion, infrastructure development, and the natural surroundings (Sanjay et al., 2020).

Flood risk management, as defined by Sayers et al. (2017), refers to the systematic process of collecting and analysing data and information, evaluating risks, considering different choices, and making, implementing, and reviewing decisions aimed at reducing, controlling, accepting, or redistributing flood hazards. It also includes the ongoing and comprehensive examination of society, making changes and adjustments to regulations, and taking activities to decrease the danger of flooding while also enhancing the ability of threatened systems to withstand and recover from such events (Gouldby et al., 2017; Sayers et al., 2017). 

The main goal of flood risk management is to utilise both structural and non-structural approaches to attain an acceptable level of remaining risk for the purpose of sustainable development (Kroos et al., 2018). Flood risk management has become the prevailing approach in public policy and engineering practice for addressing floods, particularly in industrialised nations (Kroos et al., 2018). The contemporary approach to managing flood risk encompasses a comprehensive range of management activities, including technical analysis, institutional structures, and the engagement of all actors or stakeholders within the relevant system (Hale et al., 2023). 

Flooding is a prevalent and extensive environmental issue in Nigeria (Onuoha, 2017). The issues presented by floods mostly stem from the elevation of sea levels and the incidence of storm surges. These elements pose a serious threat to human lives, property, livelihoods, and infrastructure in flood-prone areas (Onwuka, 2020). Ikekpeazu (2021) states that flooding is a severe and destructive natural calamity in the state, resulting in loss of life and widespread destruction to buildings, especially homes, farmlands, and infrastructure, surpassing the consequences of any other natural occurrence. Lagos state covers an expanse of 3,577 square kilometres and accommodates around 21,000,000 inhabitants (source: Wikipedia, 2018). A substantial area of the mainland of Lagos state was flooded in 2023. This phenomenon leads to the huge invasion of a vast land area and impacts a considerable number of individuals in diverse ways (Abolade et al., 2023). However, multiple studies have shown that the consequences of floods have impacted almost every part and crevice of the city (West, 2024). 

The flooding incident in Lagos in 2024 exposed notable deficiencies in the current flood risk management measures (Jide, 2024). This event emphasised the need to evaluate and enhance these techniques in order to reduce the negative effects of floods on urban residents. The study seeks to assess the existing flood risk management strategies in Lagos State and offer suggestions for improving their efficacy. In addition, despite Nigeria's status as the most populous country in Africa with the largest economy, there is a lack of comprehensive case studies on Nigerian flooding in many significant global flood studies and papers (Steve et al., 2023). Remarkably, the comprehensive World Bank publication on guidelines for Flood Risk Management in developing countries failed to include any case study or reference pertaining to Nigeria (Afeez et al., 2021). Hence, it is crucial to conduct additional study to establish a solid and valid foundation for the efficient design and implementation of Nigerian policies pertaining to Flood Risk Management. Specifically, it is necessary to find Flood Risk Management methodologies and systems implemented in other locations and determine how to modify and apply them to Nigeria. Therefore, the necessity for doing this investigation arises.

1.2 Statement of the Problem

The issue of flooding continues to be a long-lasting and serious problem in numerous urban regions of Nigeria, with Lagos State being especially impacted as a result of its geographical and socio-economic attributes. The 2024 severe flooding event revealed notable deficiencies in the current flood risk control measures. This tragedy highlighted the importance of conducting a thorough assessment of existing procedures and implementing more efficient strategies to reduce future flood hazards.

Lagos is surrounded by multiple freshwater streams, a lagoon, and the Atlantic Ocean. The megacity's vulnerability to coastal flooding is heightened by its geographical location, flat topography, and average elevation of just 1.5m above sea level (Ajibade et al., 2017). This susceptibility will be further intensified by the increasing sea level (Obiefuna et al., 2021; Kaoje and Ishiaku, 2017). Sea level rise exhibits regional variations on Earth, and the coastline of Nigeria will see sea level fluctuations that beyond the norm. The latest IPCC report predicts that sea levels in the Lagos region will rise by 54 cm by 2100 under the RCP4.5 scenario, and by 75 cm according to the IPCC's findings in 2022. In Lagos, the rise in sea level in the region is compounded by the extensive sinking of the land, primarily due to the extraction of groundwater and urban development. The rate of land subsidence varies between 2 and 87 mm per year throughout the city, with the highest rates observed in coastal areas and areas where substantial buildings are constructed on landfills (Ikuemonisan and Ozebo, 2020). If global warming exceeds 2°C, the combination of subsidence and sea level rise in the region might result in a relative sea level increase of almost 90 cm in Lagos by the year 2100. This information is supported by the IPCC (2013), Jevrejeva et al. (2016), Bamber et al. (2019), and Johnson (2021).

A study indicates that a significant proportion of Nigerians either underestimate the danger posed by flooding or are unaware of the potential gravity of its repercussions. Insufficient understanding of potential dangers can result in inadequate preparation and ineffective execution of measures at both individual and community levels to reduce those risks. Ayobami, in the year 2024. In addition, the general populace has limited knowledge and awareness regarding the factors that contribute to floods, the areas that are most susceptible to them, and the most efficient methods for reducing their impact. Incorrect ideas and a lack of comprehension might lead to insufficient responses when confronted with flood conditions. Okafor (2024) argues that existing communication and education efforts aimed at enhancing flood awareness may be ineffective or insufficient. Information transmission may not adequately reach all segments of the community, particularly those who are vulnerable and marginalised. Disadvantaged populations, such as those living in informal settlements, are disproportionately affected by floods due to their limited access to resources and information. In order to mitigate the overall risk of flooding in Lagos, it is imperative to enhance their awareness and preparedness. 

Although there have been investments by the public sector in physical infrastructure and institutional capacity building for flood risk management, Lagos is still ill-equipped to effectively manage or finance urban flood risk. The public and commercial sectors' capacity to effectively manage and transmit flood risks has been hindered by limited coordination, insufficient technical skills and experience, and inadequate data and models. The flooding incident that occurred in Lagos in 2024 was exceptionally severe and revealed notable deficiencies in the existing flood risk control systems. This study aims to assess existing measures and suggest enhancements to decrease future flood hazards and strengthen the resilience of urban residents in Lagos.

Objectives of the study

The primary objective of this study is to critically Assess Flood Risk Management Strategies in Urban Areas of Nigeria: a case study of 2024 flooding event in Lagos state. Specific objectives of this study are to:

To assess the level of awareness of flood risk management practices by residents of Lagos

To identify the strengths in the existing flood risk management practice.

To examine the response measures implemented during the 2024 flooding event, including emergency management, relief efforts, and recovery processes

To develop comprehensive recommendations for enhancing flood risk management strategies in Lagos State.

1.4 Research Questions

The following research questions which are in line with the objectives of this study will be answered in this study:

What is the level of awareness of flood risk management practices by residents of Lagos?

What are the strengths and weaknesses in the existing flood risk management practice?

What are the response measures implemented during the 2024 flooding event, including emergency management, relief efforts, and recovery processes?

What are the recommendations for enhancing flood risk management strategies in Lagos State?

1.5 Research Hypotheses

The following research hypotheses will validate this study;

Ho: The level of awareness of flood risk management practices by residents of Lagos is low.

Ha: The level of awareness of flood risk management practices by residents of Lagos is high.

1.6 Significance of the study

This study is important because it seeks to conduct a comprehensive evaluation of the flood risk management techniques in Lagos State, specifically focusing on the 2024 flooding event as a specific example. The study will enhance the creation of more efficient and enduring flood management policies and practices by identifying deficiencies and suggesting specific enhancements. The results will be of great importance to politicians, urban planners, and community leaders in improving the ability of Lagos and other urban areas in Nigeria to withstand future flooding incidents. 

The study can provide policymakers and urban planners with valuable insights into the efficacy and limitations of current flood risk management techniques in Lagos State. This can result in enhancements in the process of creating policies and developing infrastructure with the goal of reducing future flood hazards. Lagos State, as a prominent metropolitan hub in Nigeria, regularly confronts substantial flood issues as a result of its geographical and infrastructural configuration. An analysis of the flood event that occurred in 2024 offers valuable information regarding the efficacy of existing flood risk control techniques.

Furthermore, this study adds to the existing body of academic literature on flood risk management, specifically focusing on metropolitan areas in Nigeria. By recording the details of the 2024 flooding incident, it provides factual proof that may be utilised by both researchers and practitioners to enhance and perfect ideas and methods about flood risk management.

1.7 Scope of the study

Broadly, this study focus is to critically Assess Flood Risk Management Strategies in Urban Areas of Nigeria: a case study of 2024 flooding event in Lagos state. Specifically, this study seeks to assess the level of awareness of flood risk management practices by Nigerians and identify strengths and weaknesses in the existing flood risk management practice. 

Further, this study will focus examining the response measures implemented during the 2024 flooding event, including emergency management, relief efforts, and develop comprehensive recommendations for enhancing flood risk management strategies in Lagos State.

The study is carried out in Ikeja, Lagos.

1.8 Limitations of the study

As is common in all human endeavours, the researchers faced minor limitations when conducting the study. The main limitation was the lack of extensive literature on the subject, as there is limited data available for Assessment of Flood Risk Management Strategies in Urban Areas of Nigeria: a case study of 2024 flooding event in Lagos state. Consequently, a significant amount of time and effort was necessary to locate the appropriate materials, books, or information and to gather data. 

Additionally, this study is constrained by its small sample size and narrow geographical scope, focusing just on Nigeria. Consequently, the results of this study are not applicable for generalization, thereby leaving room for further research. 

Additionally, the researcher's limitations were primarily due to financial constraints, as they are a student and do not have a source of income to sustain themselves. It was challenging to afford transportation expenses to and from the study location due to the high cost of transportation, which is influenced by inflation in Nigeria today.

Furthermore, the researcher faced a time constraint due to the need to do this research while also fulfilling the obligations of attending lectures and other educational activities.

1.9 Definition of terms

Flood: Flood is an overflow of water onto normally dry land. The inundation of a normally dry area caused by rising water in an existing waterway, such as a river, stream, or drainage ditch. Ponding of water at or near the point where the rain fell. Flooding is a longer term event than flash flooding: it may last days or weeks.

Flood risk: Flood risk is a combination of the probability (likelihood or chance) of a flood event happening and the consequences (impact) if it occurred.

Urbanization: Urbanization is the process through which cities grow, and higher and higher percentages of the population come to live in the city.