CHAPTER ONE

INTRODUCTION

1.1       BACKGROUND OF THE STUDY

Flood is an overflow of water that submerges or "drowns" land. The European Union (EU) Floods Directive defines a flood as a covering by water of land not normally covered by water. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Flooding may result from the volume of water within a body of water, such as a river or lake, which overflows or breaks levees, with the result that some of the water escapes its usual boundaries or may be due to accumulation of rainwater on saturated ground in an area.

The activities of man without adequate attention to geological structure of most cities of developed and developing nations have undoubtedly contributed to reoccurrence of disaster and consequently pose threats to environmental sustainability in most of these nations (Oludare et al., 2012). This irrefutably has led or accumulated to unresolved challenges. Among the unresolved challenges being faced are vicious flood incidences experienced in the last four decades. The occurrence is stern in third world countries where there is intensity in land use, haphazard development, and unprecedented urbanization among others. According to Adeyinka et al. (2008) “Most of these cities are also characterized by uncontrolled development , substandard and inadequate housing, poor infrastructure provision and development, poor planning process and administration, weak urban governance, poor land use structure resulting to slum…’’.

There has been unprecedented occurrence of floods and its associated effects in most of the urban centers of developing countries (Montoya Morales, 2002). Several flood disasters have occurred in Nigeria in the recent past. For instance, in Nigeria, reports have shown that devastating flood disaster had occurred in Ibadan (1985, 1987, 1990, and 2011), Osogbo (1992, 1996, 2002, and 2010), Yobe (2000), Akure (1996, 2000, 2002, 2004 and 2006) and the coastal cities of Lagos, Ogun, Port Harcourt, Calabar, Uyo and Warri among others. And the most recent flood of 2012 in Nigeria that affected more than 12 states cannot be over emphasized. The incidence of flooding has become more frequent and severe around the world, a situation that has been attributed to climate change and sea-level rise (Clark et al., 1998).

 The September, 2012 flood affected several states in Nigeria including Adamawa, Kogi, Delta, Bayelsa and Rivers States, and displaced millions of people in the process. The flood rendered millions of people homeless and their means of livelihood destroyed. The social and economic impact of the recent flood incident, particularly on agricultural production and social infrastructure, cannot be overemphasized, yet the long term impacts of the recent flood in Nigeria could be more severe.

According to Oyebande (1990) water will always find its way if not well channelized. Its choice route often poses problems to man by tampering with his physical environment, health and products of agriculture, urbanization and industrialization. This has created a lot of social and economic cost on the environment and the citizenry. Few among these social and economic impacts on the environment are: outbreak of health diseases, infrastructure failure, mental health effects, building collapse, destruction of agricultural farmland and products.

Flood has been reported as a major and devastating problem in some sectors of the economy (Petak and Atkisson, 1982). Its effects are very severe to virtually all forms of land use. The severity of its impact is also reflected on the rate of development of most nations that experience such.

Though several scholars have analysed the problem of flooding in Nigeria (Atedhor, Odjugo, and Uriri, 2011; Eni et al. 2011; Etuonovbe, 2011; Dabara, 2012), most of the researches, however, focused on the health and social impacts of flooding. Eni et al. (2011) investigated the impact of flooding on farmlands in Cross River State, Nigeria using a combination of interview and laboratory methods, but the implications of flood disaster on Ngwo Udi Local Government Area seems not to have been investigated.

Moreover, it has been shown that the integration of Remote Sensing and Geographic Information Systems (GIS) provide valuable and timely spatial information in the event of a natural disaster. This approach has proved to be a very important tool in the evaluation and management of natural disaster. Pradhan (2009) analysed flood risk areas in the east coast of Malaysia using GIS and statistical models. Though effective, this method may be time consuming as every part of the affected area need to be visited for the purpose of collecting GPS data for elevation mapping and modeling. Advanced Space-borne Thermal Emission and Reflection Radiometer (ASTER) image and Shuttle Radar Topography Mission (SRTM) images provide a means of generating the digital elevation model (DEM) of the landscape and therefore, it can give an estimate of flood depth in areas inundated by flood water.

In Nigeria, flood disaster has been perilous to people, communities and institutions. Recently, so many states of the federation were affected by flooding which have claimed so many lives, damaged property, disrupt economic activities, caused grief and emotional trauma and also displaced the inhabitants of the affected environments. It shattered both the built-environment and undeveloped plan. It shattered both artificial and natural environment. Properties worth millions of naira   got lost due to flood occurrences. One prominent feature about it is that flooding does not discriminate, but marginalizes whosoever refuses to prepare for its occurrence NEMA Newsletter 2012).

Whereas flooding itself is a situation that results when land that is usually dry is covered with water of a river overflowing as a result of heavy rain, and dam over flow, flooding occurs naturally on the flood plains which are prone to disaster. It  happens without warning but with a surprise package that always delivers to unprepared community like the ones in Sokoto, Kaduna, Kebbi, Ogun, Lagos, Benue, Jos, Adamawa, just to mention a few (Daily Sun Newspaper, July 12,2011 ; NEMA Newsletter,2011).

Flood may create conditions that promote secondary treats of waterborne and vector borne diseases as in respiratory diseases. Bruce (2003) identified the possibility of human illness related to indoor mold growth in buildings. Dampness as a result of accumulated water in corners, curves and other parts of a building may promote mold growths. In more severe flooding, deaths and injuries are usually recorded. Business and agriculture are affected by flood. So many farmlands have been washed away in numerous communities, thereby contributing to food scarcity and widespread natural disaster that need serious emergency (Internet. www.undp.org).

Floods have greatest impacts on low- lying areas, river valleys, and coastal zones. The predicted consequences of global climate change which contribute immensely to recent increase of flood all over the world may well worsen the situation for both upland and low- lying areas. And Ngwo happened to be situated in a valley and top of the hill all together. Inappropriate development plan, urbanization, and poor land management will further aggravate the effects of climate change especially as relates to flooding (UNDP, 2004).

In some places, water levels are increasing, whereas it is decreasing in some other areas. The rainfall pattern is no longer what it used to be as we may experience extended rainy season or delayed rain. And whichever way many at times, lead to flood disaster.When flood disaster occurs, many environmental hazards are likely to follow. Today; it is not only the coastal communities that can be affected by flood. Poor urban planning are chief culprits in most flood cases we have in Nigeria today. This study will identify the impacts of flood on communities in Ngwo.

1.2       STATEMENT OF THE PROBLEM

Ngwo town in Udi L.G.A., Enugu state, is being threatened by the problem of flood which has been devastating the communities since 2010. Consequently, many economic activities have been paralysed, soil surface and farm lands are being washed away along with damage to crops and creation of  gullies. In a Community Report to Enugu State Emergency Management Agency (ESEMA), (2010), it was recorded that two primary school children were lost to flood in Ngwo in 2010. The Community Report to ESEMA(2010) showed that loss of lives, markets and local small business; and the destruction of infrastructure, including roads, school and health facilities, are among the major impacts. Displacements and fatalities were recorded.

Flooding incidents around the town was associated with heavy and torrential rainfall that ceaselessly fell for hours and sometimes days. Although the torrential rainfall is the immediate trigger, the risk of flooding have often been heightened in  periods prior to the rainfall through human activities, including construction of home along flood plains and river banks; siting and growth of villages and rural communities either at the foot of hills (for protection) or also along river banks.

These have been compounded by such other activities as blocking the waterways/river paths/flood plains through indiscriminate disposal of domestic and industrial waste. Essentially, the poor have borne the brunt of the situation because they are the ones who are forced by poverty to seek accommodation or build their homes in such highly vulnerable areas.  The impact of these flood disasters have often been quite overwhelming not only on the communities immediately impacted but also on the capacities of local and state disaster management agencies.

However, various efforts have been made to assuage the flood problem in Ngwo so as to reduce the impact. Such efforts include digging of catchment pit by some residents in their various compounds to reduce the surface water flow, excavations by Arab Contractors Construction Company, through the efforts of ESEMA and NEMA collaboratively, in August 2010; and construction of drainage channels in some areas.

In spite of these measures, the problem of flooding still persists in Ngwo, and no further study has been carried out on the flood hazard in the area. It is based on this situation that this study is set out to empirically examine the effects of the flooding on the environment in Ngwo. It is expected that the result of this study will provide measures that can reduce vulnerability and increase community resilience and response to flooding.

1.3       AIM AND OBJECTIVES OF THE STUDY

The aim of the study is to examine the flood disasters and their effects in Ngwo, Enugu State.

The following objectives are put forward in line with the aim of the study:

(i)        To assess the spatial extent of flood inundation and identify the most affected areas;

(ii)       To evaluate the effects of flooding on the environment

(iii)    To assess the extent of damage encountered as a result of flood in Ngwo.

1.4       RESEARCH QUESTIONS

(i)        What is the spatial extent of flood inundation and which areas of the town are affected?

(ii)     What are the effects of flood disaster on the communities and the extent of damages?

(iii)     What measures can be adopted to reduce flood vulnerability in the area?

1.5       RESEARCH HYPOTHESES

HO 1: There is no significant relationship between flood disaster occurrence and flood disaster effects.

Ho 2: The effects of flood disaster do not vary significantly among communities in Ngwo

Ho 3: There is no identifiable significant pattern of flood effects in Ngwo communities

1.6       SCOPE OF THE STUDY

The extent of this study will be on effects of flood disaster on Ngwo and its environment. The research will identify the likely causes of flood and evaluate the effects in the area through the use of Geographical Information System.

It will also focus on the assessment of the extent of damage caused by flood and its environmental hazards through the use of GIS remote sensing, with a handheld GPS hazard map, the disaster problems are identified. Finally, recommendations were made based on the findings. These will help in preparation, prevention, mitigation and response and recovery in future disaster management.

1.7   SIGNIFICANCE OF STUDY

This study will be of great benefit to both citizens and settlers in Ngwo communities, professionals, students and academics, government and the general public at large. The study will help Udi Local Government Area to know the areas that are prone to flood in communities in Ngwo; the extent of damage of flood in the areas; and the likely causes of flood in Ngwo. Also, the study will guide town planners and members of the public that dwell and/ or do business in Ngwo on better land use/ land cover of the environment.

1.8     LIMITATIONS OF THE STUDY

Some respondents had wrong perception of the questionnaire. Some of them thought had the impression that it is governmental project, and refused to cooperate in filling the questionnaire.

Again, some respondents demanded for money before they could respond to the questionnaire. Not meeting such demand could have affected their disposition to filling the questionnaire. High cost of obtaining data from NIMET reduced the number of years of rainfall data that was used for the study.

1.9       DEFINITION OF TERMS

(a)       Arc GIS: Arc Geographic Information System

(b)       Coordinates: Coordinates define a point with reference to an ellipsoid. Coordinates are defined using latitude, longitude and ellipsoidal height.

(c)       Fluvial: Connected with water.

(d)       GPS:  Global Positioning System.

(e)       Gauge/ Gage:  An instrument for measuring the amount of level of something.

(f)        Alluvial:  Made of sand or earth that is left by rivers or floods.

(g)       Percolate:  (of a liquid –water) to move gradually through of surface that has very small holes or spaces in it. Water percolates down through the rocks.

(h)       Inundation: To cover an area of land with a large amount of water.

(i)        Handheld Differential GSP: Differential Global Positioning System is a system that utilizes differential code connections to achieve an enhanced positioning accuracy of around 0.5 – 5m.

(j)        Topography:  The form of land of a particular region.

(k)       Space segment/Satellite:  The part of the whole GPS system that is in space.

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