ASSESSMENT OF THE IMPACT OF FLOODING DAMAGES TO PEOPLE BUILDING AND INFRASTRUCTURE CONSTRUCTED ON FLOOD PLAIN AREAS

CHAPTER ONE

INTRODUCTION

1. Background of the Study

The globe has seen a number of noteworthy catastrophes throughout the years that have resulted in substantial death tolls, catastrophic financial losses, and astounding environmental destruction. Community members are most affected by natural disasters (Buba et al., 2021). Floods are among the world's most destructive natural catastrophes, taking more people and damaging more property than any other natural occurrence. They are also the most common (Kundu & Kundu, 2011; Rabalao, 2010). According to statistics, flooding affects almost 100 million people worldwide each year (Sayama et al., 2010).

Developing nations, particularly those on the African continent, are more susceptible to flood catastrophes because of their inadequate governmental infrastructure and the absence or improper application of laws governing disaster prevention and mitigation. Floods are the most frequent and recurrent natural catastrophe, and they are becoming more frequent, severe, and widespread in Nigeria, one of the most disaster-prone nations in Africa (FGN, 2013). In 25 of the 36 states, the most catastrophic floods in the nation's history struck between July and October of 2012. The impact on human, material, and production loss was extremely large and unprecedented: 3,891,304 impacted, 5851 wounded, 363 dead, and 387,153 displaced(FGN, 2013). Major metropolitan hubs like Lagos, Port Harcourt, Kano, Kaduna, etc. frequently experience flooding. Anthropogenic activities, or human interference with natural processes, can result in floods. These activities include urbanisation, deforestation, population growth in low-lying plains that are vulnerable to flooding, increasing settlement areas, and changing climate and drainage patterns(Nharo, 2016; Adefisan et al., 2015; Nkwunonwo et al., 2015). Humans have built dams and other water control structures in an effort to use the water resources that are already accessible to them. Floods have been caused by these constructions' breakdowns(Komolafe et al., 2015; Rabalao, 2010).

Among the most destructive natural catastrophes in the world, flooding, particularly river floods, claims more lives and damages more property than any other natural occurrence (Adeaga, 2018). Despite not being the primary cause of mortality in Nigeria, it is the most common natural catastrophe to strike and uproot more people than any other (Buba et al., 2021). Therefore, it is imperative that the relevant authorities, particularly in emerging nations, comprehend, avoid, plan for, and minimise its impacts. This is especially prevalent presently because of the emerging nations' fast urbanisation and population expansion, which can lead to a concentration of people in unplanned environments.Thus, the best ways to ensure flood preparedness and risk reduction, according to Hue et al. (2019), are to identify areas that are susceptible to flooding as well as gather and analyse data on the elevation, slope orientation, proximity of built-up areas to drainages, network of drains, presence of buffers, extent of inundation, cultural practices as well as attitudes and perceptions.

According to Geo-science Australia (2013), flooding is essentially defined as "water where it is not wanted." A condition that arises when a typically dry portion of the earth's surface is flooded and covered in water as a result of heavy rainfall or a water body overflowing is another way to conceptualise it.In addition, pagasadost (2013) described flooding as a “natural hydrological phenomenon and its occurrence is usually the aftermath of metrological events such as seismic activities, astronomically influenced phenomena (high tides coinciding with occurrence of high rainfall), construction of temporary dams, as well as the failure of hydraulic and other control structures.” Although the severity and extent of floods vary according to geography, human activity intensity, water volume, and stakeholder readiness, the repercussions of floods are always devastating.

Flooding is the overall temporal situation of partially or totally submerging ordinarily arid areas due to tidal or inland water overflow, or to an unusually high and quick build-up of runoff(Jeb&Aggarwal,2018).The most frequent natural calamity to have an impact on society worldwide is flooding. According to Dilley et al. (2005), 82 percent of the world's population lives in areas that are susceptible to flooding, which makes up more than one-third of the planet's land area. The explanation is due to the low-lying beaches and river flood plains' extensive geographic distribution as well as their long-standing appeal to human habitation.Although floods are a natural occurrence, they may be extremely dangerous when they inflict more damage to property and more casualties than the affected communities can handle. They have an impact on all kinds of settlement, ranging from big cities and metropolitan areas to little villages, mid-sized market towns, and service centres. People who relocate from rural to urban areas, or within cities, frequently dwell in places that are particularly susceptible to floods, rendering them extremely vulnerable in the absence of flood defence systems, in many parts of the world(Jhaetal.,2012).

Urban flooding can occur in the form of coastal, fluvial, pluvial, or even a mix of these flood types. Extreme tidal conditions brought on by high tide levels, storm surges, and wave activity result in coastal flooding. When a river's flow surpasses the river channel's ability to hold it, a flood known as a fluvial flood occurs. While a pluvial flood occurs when the pace of rainfall surpasses both the ground's ability to hold onto water and the storm water drains' ability to remove the water(Balletal.,2018).The phrase "invisible hazard" refers to the fact that pluvial flooding frequently happens suddenly, with little notice, and in areas that are not visibly prone to floods (Houston et al., 2011). Urban areas with a lot of impermeable terrain and insufficient drainage infrastructure are prone to pluvial floods. Urbanisation leads to an increase in impermeable surface area, which puts people at risk of flooding when man-made drainage systems and natural streams cannot handle the surge in runoff that follows intense downpour(Youssef&Pradhan,2011).

Urbanisation and anticipated climate change are both likely to contribute to an increase in the frequency of urban pluvial flooding (Ugarelli et al., 2011; Simes et al., 2014). This kind of flooding is almost always possible and may be extremely damaging and disruptive in densely populated places with high property, vital infrastructure, and people densities. Due to the high frequency of this type of occurrence, the quantities involved and the danger associated with pluvial flooding frequently result in constant economic losses and subsequent damage over time(Freniet al.,2010).Related effects of pluvial flooding mostly include intangible costs from traffic jams, road closures, public and commercial function closures, and personnel evacuation, in addition to economic losses from damage to buildings and their contents and infrastructure. Extreme weather events and flood disasters have a huge economic cost on a global scale. If this cost increases due to climate change, it will mostly affect the world's poorest nations and people. Therefore, it is critical to decrease developing nations' susceptibility to climate change and boost their ability to adapt at the local, national, and regional levels(UNFCC,2017).The effects of floods are not caused by an abundance of water; rather, they arise from the negative interactions that this water has with the natural and man-made ecosystems, leading to harm, loss of life, and devastation. When natural floods happen in places with a high concentration of human habitation and development, that's what turns them into disasters. Otherwise, advantages of flooding exceed negative consequences when left in their natural condition(Bradshawetal.,2017).While most people consider flooding to be a bad thing, there are really some advantages to flooding. In actuality, having natural floods is better for nature than not having any at all. An urban slum dweller and a rural farmer will experience flooding very differently. For the farmer, flooding is a natural force that may be harnessed or endured for potential long-term benefits, but for the urban dweller, flooding is at best an annoyance and at worst a disaster that destroys everything they own(Jhaetal.,2012).

Approximately one-third of all worldwide disasters resulting from geophysical hazards are routinely caused by floods (Smith and Ward, 1998). It is predicted that they will become more frequent and devastating in the future, seeming to be more widespread and destructive than they were centuries before (Parker, 2016). Also, more people are residing in places that are vulnerable to flooding. There is strong evidence that, as human habitation of floodplains grows globally, vulnerability to floods is increasing at an accelerated rate, despite several nations' attempts to control development in these areas(Jhaetal.,2012).Floods, especially urban floods, are thought to be the cause of around half of catastrophes globally, and flooding is responsible for 84% of disaster-related deaths, according to UN-Water (2011). These are among the most common and expensive natural disasters in terms of the hardship they cause to people and the money they cost the US and the rest of the globe(Parker,2016).Today, millions of people worldwide are affected by the all too frequent occurrence of flooding-related deaths and property damage. One of the main natural calamities that impairs the prosperity, safety, and well-being of people living in human settlements is flooding(Jhaetal.,2012).

Nigeria follows a similar path to the rest of the globe. More people are displaced by floods than by any other calamity, maybe as a result of the fact that 20% of Nigerians are vulnerable to flooding(Etuonovbe,2011).Therefore, flooding is a recurring issue in Nigeria that constantly results in fatalities and community relocation. For example, in 2010 floods resulted in the deaths of around 1,555 individuals and the displacement of another 258,000(Babatunde, 2011).Similarly, in2012,floodsclaimed361lives,anddisplaced2.1millionpeople(Tkunbo&Ezigbo,2012). It is based on this backdrop that the present study seeks to examine the impact of flooding damages to people building and Infrastructure constructed on flood plain areas.

1. Statement of the Problem

In developing nations, flooding is seen as one of the most pressing environmental issues that local authorities must deal with. Undoubtedly, there is a serious environmental issue or significant risk that is persistently impeding the efficient operation of the urban environment, particularly in the areas of maintained infrastructure and services that are essential to a sustainable way of life.Severe floods that happen in human-populated regions cause natural disasters that cause significant disruptions to the lives and property of big urban and rural communities(Suriya & Mudgal, 2012).

The top-down approach to flood management in Nigeria has so far mostly included state and federal authorities, leaving little room for non-state actors and local communities to influence policy responses and decision-making (Olorunfemi, 2011). This has led to serious shortcomings in the way flood management techniques have been developed. The interactive strategy used in this study was influenced by this circumstance. Flood catastrophes have been a recurrent occurrence in Kogi State, especially in Lokoja and the surrounding areas. Flooding completely destroyed a number of settlements in the Lokoja, Ibaji, and Kogi Local Government Areas (LGAs) between 2010 and 2012. The 2012 floods had an impact on 344 villages throughout the State, resulting in the submersion of several farmlands (Okpala-Okaka et al., 2013). Floods not only cause fatalities and property damage, but they also impede the best use of the land and appropriate administration and control of water resources (Ojigi et al., 2013).

Furthermore, Adeosun (2012) revealed that the Federal Ministry of Environment declared that the adverse impact of climate change, which has recently resulted in a nationwide flood, has the potential to thwart efforts to achieve the Millennium Development Goals (MDG). This does pose a serious danger to the gains gained thus far in the fight against severe poverty and illness.The devastation caused by urban floods is increasing due to the consequences of these natural disasters; thus, it is critical that we continuously research the characteristics and effects of floods in order to implement suitable disaster risk reduction measures that will lessen the impact of floods.

These scholars have contributed to the knowledge available regarding flooding, encroachment, and flood-prone places in Nigeria; however, they have not evaluated the flood dangers in all of the areas that are susceptible to flooding. Furthermore, particularly in urban regions without large rivers, relatively few techniques have concentrated on local floods in tiny urban watersheds and the rainfall runoff created there.However, the examination of flood damage and loss has been impeded by insufficient data, especially when it comes to the development process and triggering variables (Suriya &Mudgal, 2012). It appears that not much research has been done on the causes of flooding and the harm that floods may inflict, specifically with relation to the effects of unlawful construction on the study area's riverbank, flood plain, and flood-prone areas.Thereisstilla dearth on how flooding damages people building and Infrastructure constructed on flood plain areas in Nigeria.

1.3 Research Questions

          The following questions guided this study;

1. What is the impact of flooding on people building and Infrastructure constructed on flood plain areas in Nigeria?
2. What are the causes of flooding in Nigeria?
3. What are the strategies that can be adopted to mitigate flooding in Nigeria
   1. Objectives of the Study

The main objective of this study is to examine the impact of flooding damages to people building and Infrastructure constructed on flood plain areas in Nigeria. Other specific objectives of the study include;

1. To determine the impact of flooding on people building and Infrastructure constructed on flood plain areas in Nigeria
2. To identify the are the causes of flooding in Nigeria
3. To identify the strategies that can be adopted to mitigate flooding in Nigeria

1.5 Research Hypotheses

          The following were hypothesized;

Hypothesis One

H01: There isno significant impact offlooding on people building and Infrastructure constructed on flood plain areas in Nigeria

H01: There isa significant impact offlooding on people building and Infrastructure constructed on flood plain areas in Nigeria

Hypothesis Two

H01: There isno significant relationship betweenflooding andpeople building and Infrastructure constructed on flood plain areas in Nigeria

H01: There isa significant relationship betweenflooding and people building and Infrastructure constructed on flood plain areas in Nigeria

1. Significance of the Study

Thefindingsofthisstudywillbebeneficialtourbanandinfrastructureplanners,riskmanagersanddisasterresponseoremergencyservicespersonnelduringextremeandintenserainfallevents.

Furthermore,publicandprivatebusinesses,privatehouseowners,housingcorporationscandecidewhetheritisworthtakingoutafloodinsurancepolicyorspendingadditionalmoneyonprivatefloodprotectionmeasures.

The findingsof this studycanprovide additionalinformationtotheexistingknowledgeinthefieldoffloodassessment.

The research work will provide a baseline for future planning and environmental modeling, simulation and for making early warning systems. Rivers State stands to benefit immensely because, all abnormalities identified will be addressed by flood disaster management planners and environmental managers, and outcome of the research will be useful to Rivers State Government.

It will also serve as a reference material for further investigations and developmental processes to generate interest on the sector particularly how devastating flood hazard changes the lives of people in the study area and further more to examine the effects and benefits of flood hazard to residents in Port Harcourt.

The findings of this study will also help the general populace to know how flooding damages to people building and Infrastructure constructed on flood plain areas in Nigeria.

1. Scope of the Study

This study is limited to the assessment of the impact of flooding damages to people building and Infrastructure constructed on flood plain areas in Nigeria. Participants from this study were recruited from Port Harcourt, Rivers State, Nigeria.

1. Operational Definition of Terms

Flooding: Floodingisageneraltemporalconditionofpartialorcompleteinundationofnormallydryareasfromoverflowofinlandortidalwatersorfromunusualandrapidaccumulationofrunoff.

Flood Plain Areas: Flood plain areas are thosegeneral flat area of land next to a river or stream.

Infrastructure:Infrastructure is the basic physical and organizational structures and facilities (e.g buildings, roads, power, supplies) needed for the operation of a society or enterprise