The climate of Lekki is the wet equatorial type influenced by nearness to the equator and the gulf of Guinea. There are two main seasons namely, raining season and dry season, which usually lasts from April to October and October to March respectively. The raining season has two peak periods; May to July and September to October, with rainfall being heaviest during the first peaked period. Floods usually result at these period which are aggravated by the poor surface drainage system of the coastal lowland. It has an elevation of less than 15m above sea level. Lekki records 1675.5mm of rainfall.
Lekki has a constant high temperature around November to December, and February to March, while the lowest temperature occur around June to July, which coincides with the middle of the peak of the raining season. The humidly level is generally high all over the area throughout the year.
LAND USE PATTERN
The nature of land use in the area is predominantly rural type which include residential, commercial, education. Also road networks are being constructed to allow for accessibility, and because of transportation, most of the roads are paved. The area is now greatly and wrongly exposed to flooding due to much use for the various purposes mentioned above. Much of the deposits and over land flow have polluted rivers in the area.
SOIL GEOGRAPHY
The soil in Lekki is mostly Hydromorphic which develops a poorly drained condition and accumulation of peaty materials on the surface. The poor drainage situation of hydromorphic soils is caused by several factors including generally low relief, high water table and high rainfall distribution all year round.
Hydromorphic soils are found in coastal swamps of mud flats. Sometimes the mud flats are former lagoons which have been silted as the coastline shifts seawards. Hydromorphic soil also include the variety of mudflats found along coastal river valleys below relief of the lower beaches of the rivers in the coastal areas. This causes water to stagnate between the surface of the ground and create peaty soils.
The major characteristics of hydromorphic soil is poor drainage. Whatever soil management technique that have been introduced, whether traditional or modern, hydromorphic soils have proved wonderful in agriculture. For instance, the rice field of Abakaliki in Ebonyi state is predominantly hydromorphic soil. Since the soil is non-cementing or non-compatible, it causes lack of structural stability and highly susceptible to soil erosion.
GEOMORPHOLOGY
Lekki has flat topography. It is naturally made up of depositional land form which include; wetland, barrier Island, beaches, low-lying tidal flats and estuaries. The most significant topological feature in the area is wetland which covers a reasonable land area. The nature of the watershed is a factor that facilitates flooding. The watershed has less tributaries leading to discharge of excess water to the surrounding flood plains. Because the terrain is steeper near the watershed, flood water is encouraged to be swift., the shape and configuration of the land has been altered by sea actions. In addition, the area is composed of soft, unconsolidated materials such as sand.
1.5 RESEARCH QUESTIONS
· How does flooding affect the socio-economic activities of the area?
· Which specific areas are being affected by flooding?
· Are there measures and techniques adopted by the government in checking and controlling flooding in the area?
· What is the efficiency rate of the measures adopted?
1.6 HYPOTHESIS
There is a significant relationship between flooding in the area and decrease in socio-economic activities.
1.7 OUTLINE OF THE ESSAY
The entire work is divided into five chapters. The first chapter gives introductory overview of the subject matter. This include statement of problem, research questions and study area. The hypothesis for the project work is derived. It also contains the aim and objectives.
The second chapter deals with literature review and causes of flooding. Chapter three contains the research methodology which include the study population and method of data collection. Chapter four deals with the analysis of data collected and the impacts of flooding on the socio-economic activities of the study area.
Chapter five summaries the entire work. The section will also make some suggestions which will go a long way towards ameliorating the problem of flood. It also contains the conclusion.
CHAPTER TWO
2.1 THEORETICAL FRAMEWORK
A flood occurs when a river rises to leave its bed and cover adjacent lands. It was observed that flooding is affecting the study area. Based on this, it becomes expedient that models be adopted to serve as a basis for proper identification of flood and subsequent magnitude.
In this regard, the work of the National Weather Services (formerly the Weather Bureau) is workable in identifying flood and their magnitude.
The Weather Service operates a flood forecasting service through offices located at strategic points along major river systems. They are the ones that provide a flood warning services. There are three programs that contribute to flood warning; A severe storm unit forecasts severe weather for the entire nation. A quantitative precipitation unit forecasts precipitation expected in the next 24 hours over the country and delineates areas of heavy rainfall to alert local flash-flood-warning networks. The third program involves radar surveillance, which is especially useful in spotting scattered thunder storms. Current and repetitive data from earth orbiting satellite are proving especially valuable.
The magnitude of a flood is usually measured by the peak discharge or highest stage of a river during the period of flooding. As the flood history of any river shows, large floods occur less frequently than smaller ones-that is, the greater the discharge or higher the stage, the less likely the flood. A tool used by the National Weather Service to present flood history of a river is the flood expectancy graph.
When a flood threatens, forecasters analyze precipitation patterns and the progress of high waters moving down stream. By examining flood history of the rivers and stream concerned, they developed specific flood forecasts. These are delivered to communities within the associated district, which usually covers one or more large watersheds. Flood warnings are publicized by every possible means, and various agencies cooperate closely to plan the evacuation of threatened areas and the removal or protection of property. Additionally, flood patterns in drainage basin are as complex as the weather, the floods and weather are equally variable and both include a level of unpredictability.
