AN ASSESSMENT OF THE PREVALENCE AND CAUSES OF FLOOD IN LAGOS ISLAND IN 2024

CHAPTER ONE

INTRODUCTION

Background of the Study

Globally, flood has received a great deal of scholarly interest throughout the years, particularly in developing countries such as Nigeria. Although there are several types of environmental problems and issues that result, including soil degradation, greenhouse effect change, ozone depletion, drought, desertification and deforestation, industrial pollution, water contamination, and waste management. Howbeit floods are among the most prevalent and widespread. The conventional flood concept is the overflowing of a water body's riverbanks, which results in an uncontrolled spread of water that exceeds the water carrying capacity of the catchment region that surrounds the water body. This causes floods (Okorafor et al., 2015). Floods, like drought and desertification, are natural hazards that arise as a result of excessive hydrological (runoff) events, according to Danumah, Odai, and Saley (2016). According to Bello and Jeb (2016), flooding is the most common natural catastrophe, with the frequency of documented flood incidents growing dramatically over the previous 20 years. According to United Nations-Water (2011), there has been a dramatic increase in the number of persons killed or badly injured by flood catastrophes, which affect an estimated 520 million people globally each year, resulting in up to 25 000 deaths in a single year. Floods are widespread across the planet, according to a history of flood occurrences provided in NASA's Earth Observatory (EO), which was cited in Bello, & Jeb (2016), with the Northern Hemisphere and the Southern Hemisphere seeing the most extreme flooding. According to Bello and Jeb (2016), extreme rainfall in Brazil, Bolivia, and Peru during December 2006 to January 2007 caused major flooding and landslides in those nations.

Significantly, the essence of flood attention in study is always linked to its origins, the consequences of severe property damage and even irreparable loss of life, and the control methods. Flood is one of the key problems preventing Africa's population from overcoming poverty, and flood victims are typically urban poor (Adetunji and Oyeleye, 2018). A flood occurs when a watercourse overflows its banks and submerges adjacent regions. To add to this, Egbinola, Olaniran, and Amanambu (2015) define flood as an overflow of a body of water that submerges land. Flood, as defined by the European Union (2007) and Adetunji et'al (2015), is a temporary covering of land by water that was not previously covered by water. Flooding, according to Nelson (2018), is a natural result of stream flow in a constantly changing environment. Flooding to Nelson represents abnormally high rates of discharge, frequently resulting in inundation of land near to streams, and is generally produced by severe or protracted rains.

Surprisingly, many settlements in Nigeria's coastal region, and among other places, have weak drainage systems and are thus prone to floods. Flooding threatens an estimated 25 million people, or 28 percent of Nigeria's population, who live in the coastal zone (NCAR, 2024). Flooding poses a significant risk to riverside populations and floodplains, as well as significant impacts on the environment, including aquatic fauna and flora and bank erosion (Twumasi, Merem, Ayala-Silva 2017). Therefore, risk assessment is required in order to determine the likelihood of flood occurrence and its negative implications. According to Twumasi et al. (2017), many aspects such as vulnerability and exposures must be considered in the real evaluation of catastrophe scenarios and losses. Thus , flood risk is the result of flood dangers, susceptibility, and exposure of people, which necessitates an appropriate response in order to minimize or lessen the consequences of flood. Various communities have and will continue to experience the effects of meteorological disasters, such as flooding, as a result of unpredictable seasons (Adelekan, 2016; Tambo, 2016). While natural disasters affect the entire world, underdeveloped countries are particularly susceptible. According to Nicholls et al. (2007), there are roughly 800 million people currently residing in flood-prone regions in developing nations. Out of these, around 70 million people face floods every year (Surminski and Oramas-Dorta, 2014). 

Mirza (2020) proposed that Africa is prone to a rise in flood occurrences, which could consequently impact water systems, infrastructure, health, and impede development. Nevertheless, the ability of developing countries to cope with flooding rely on their implementation of preventive measures and their future development strategies (Mirza, 2020). Nigeria is among the emerging nations that have experienced a growing susceptibility to flooding. From 2009 to 2023, Nigeria faced the consequences of natural disasters. These consequences were worsened by insufficient infrastructure, poverty, limited knowledge about disaster risks, and substandard living conditions (Daramola et al., 2016). On the other hand, the inadequate management options and enforcement of flood control are caused by a deficient institutional and legislative framework in the development control process of developing countries. Developers often construct buildings without taking into account the specific flood-prone zones and locations that are prone to flooding. Likewise, insufficient funding from relevant organisations hinders the establishment of drainage distribution channels and other management strategies that can effectively reduce flooding in the environment. Available research have observed that flooding has had a significant impact on the lives, properties, and environmental sustainability. Flooding, as a natural hazard, has significant adverse effects on both the environment and the economy. For example, flooding has a detrimental impact on housing, roads, and other physical infrastructure, rendering these locations unappealing to residents. In spite of the foregoing, literature that are aimed at analyzing the prevalence and causes of flooding are inadequate. Against this backdrop, a survey will be conducted in order to assess the prevalence and causes of flood in Lagos Island in 2024.

1.2 Statement of the Problem

In recent years, urban flooding has been identified as one of the most pressing and serious environmental concerns confronting municipal authorities in developing countries. Floods are the leading cause of catastrophe losses in Nigeria, according to the EM-DAT database (Komolafe et al., 2015b), and with the projected rise in rainfall intensity due to climate change, several river basins in the country are expected to flood. The oldest documented instance of flooding in Lagos can be traced back to July 1947, when excessive rainfall led to the occurrence of this catastrophe. Although Lagos has a long history of flooding, the problem has been worsened by the expansion of unplanned settlements in the city. Currently, only 45% of the metropolitan area is equipped with storm drains, and less than 30% of these drains are consistently maintained (Nwigwe & Emberga, 2018).  Ayoade & Akintola (2023) have acknowledged that the increased vulnerability to flooding in Lagos, particularly on the Island, during the rainy season has been a longstanding concern for inhabitants, who have identified it as one of the top three significant environmental issues.

Furthermore, the process of urbanisation, along with inadequate drainage infrastructure, has a substantial role in causing flooding in Lagos Island. The rapid and uncontrolled growth of cities has resulted in the intrusion of natural watercourses and wetlands, which historically served as barriers against flooding. A research conducted by Adelekan (2023) revealed that the drainage system in Lagos is insufficient to handle severe rainfall, resulting in waterlogging and flooding. Likewise, the urban drainage infrastructure frequently experiences blockages caused by garbage and waste, impeding the smooth movement of water and intensifying flood situations.

In addition, the Nigerian Punch (2024) provided a comprehensive account of the regular instances of flooding in many areas of Lagos, Nigeria, including Ikoyi, Ipaja-Ayobo, Ajegunle, Ikorodu, Agiliti, Mile 12, and Victoria Island. In recent decades, flooding has resulted in the loss of several lives and properties. Flooding in Nigeria is primarily attributed to the inadequate enforcement of planning policies, obstruction of streams and channels due to indiscriminate waste disposal practices, and human activities in flood plains. This conclusion is supported by various studies conducted by Ituen et al. (2014), Ekpoh (2015), Udoh (2015), Evan et al. (2017), and Abraham et al. (2021). The report determined that there is a necessity for the coordination of flood control efforts among the pertinent departments (Nigerian Punch, 2024). It also demanded a clearly defined flood management policy and a societal shift in thinking about this important topic. Hence, it is in the light of these that the study seeks to assess the prevalence and causes of flood in Lagos Island in 2024.

 1.3  Objectives of the Study

The main purpose of this study is to assess the prevalence and causes of flood in Lagos Island in 2024. Specifically, the study will;

Determine the prevalence rate of flooding incidents in Lagos Island.

Determine the factors contributing to flooding in Lagos Island.

Assess the impacts of flooding on residents and businesses in Lagos Island.

Evaluate the effectiveness of flood control infrastructures in Lagos Island.

1.4  Research Questions

The following questions have been prepared for the study:

What is the prevalence rate of flooding incidents in Lagos Island?

What are the factors contributing to flooding in Lagos Island?

What are the impacts of flooding on residents and businesses in Lagos Island?

How effective are the flood control infrastructures in Lagos Island?

1.5 Research Hypotheses

H0: Flooding has no significant impacts on residents and businesses in Lagos Island.

Ha: Flooding has significant impacts on residents and businesses in Lagos Island.

1.6 Significance of the Study

This research will empower urban planner to create urban development plans and infrastructure projects that are more resilient to floods. Possible interventions may encompass enhanced drainage infrastructure, flood prevention strategies, and land-use policies targeting the reduction of Lagos Island's susceptibility to future flood occurrences.This includes improved drainage systems, flood mitigation measures, and land-use regulations aimed at reducing the vulnerability of Lagos Island to future flood events.

Furthermore, policymakers at local, state, and federal levels will use the findings to develop and enforce specific laws and regulations that tackle the underlying factors contributing to flooding in Lagos Island.Moreover, subsequent researchers will use it as a literature review. This means that other students who may decide to conduct studies in this area will have the opportunity to use this study as available literature that can be subjected to critical review. Invariably, the result of the study contributes immensely to the body of academic knowledge with regard to the prevalence and causes of flood in Lagos Island.

1.6 Scope of the study   

The scope of this study is boarded on the prevalence and causes of flood in Lagos Island in 2024. Empirically, this study will determine the prevalence rate of flooding incidents, the factors contributing to flooding, the impacts of flooding on residents and businesses and the effectiveness of flood control infrastructures in Lagos Island.

Geographically, the study will be delimited to residents of Lagos Island.

1.7 Limitation of the study

In the course of carrying out this study, the researcher experienced some constraints, which included time constraints, financial constraints, language barriers, and the attitude of the respondents. In addition, there was the element of researcher bias. Here, the researcher possessed some biases that may have been reflected in the way the data was collected, the type of people interviewed or sampled, and how the data gathered was interpreted thereafter. The potential for all this to influence the findings and conclusions could not be downplayed. More so, the findings of this study are limited to the sample population in the study area, hence they may not be suitable for use in comparison to other schools, local governments, states, and other countries in the world.

 1.9 Definition of Terms

Flood: an overflow of water that submerges land which is usually dry. Floods can occur due to various reasons including heavy rain, rivers overflowing, dam breakages

Rainfall: the amount of rain that falls over a certain period in a specific area.

Drainage: a natural or artificial removal of surface and sub-surface water from an area.

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