1.1 Background of the Study
Geographers have over the years noted regional imbalances in warning trends that seemed to render the term “global warning” invalid. While annual temperature averages unquestionably continued to rise through the late 1990s and early 2000s, over-heated areas in the Northern Hemisphere often were matched by excessively cool regions in the Southern Hemisphere (Blij, Muller, Williams, Conrad and Long, 2005).
The discovery and extraction of natural resources has brought different consequences to countries that are endowed with such resources. While some of these nations have become economically strong and self sustaining, others have being drawn into serious economic hardships and conflicts due to the atmospheric influence of man and his activities while man through his various actions deliberately or inadvertently influence weather and climate which brings about climate change refers to an increase in average global temperatures.
Natural events and human activities are believed to be contributing to an increase in greenhouse gases such as carbon dioxide (CO2). Nigeria is experiencing adverse climate conditions with negative impacts on the welfare of millions of people. The climate of an environment or a region are usually explained in terms of the prevailing climatic elements of temperature, rainfall or precipitation, relative humidity, evaporation, solar radiation etc. The description of these climate element or parameters in any region is known as climatic characteristics of what region. Among all these parameters, the most widely used measure of climatic description is the temperature, rainfall or precipitation and relative humidity (Oguntoyinbo, 1983 and Ayoade, 1992).
Over the years, studies of climatic characteristics have been limited to the micro scale known as micro climatic characteristics (Efe, 2002; Oguntoyinbo, 1981; Ojo, 1988; Figurola, 1995; and Efe and Aruegodine, 2003). Human activities have much effect on the climate of Abraka as most of these climatic parameters are being altered by the numerous activities of human in the region. Some of these human activities are the method of farming, gas flaring within the environment or neighbouring communities, transportation, fumes from factory buildings, illegal oil bunker, fumes from generator sets, improper waste disposal, deforestation etc.
Lately the heat wave all over the country has been unbearable. Even with rain, the heat is still unbearable. Have you ever wondered why the sun is so hot? The heat is caused by global warning. Global warning is the rise in the atmosphere. This is called the Green House Effect. A Green House Gas (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the green house effect.
The primary green house gases in the Earth’s atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone. The effect of global warming include extreme weather conditions, heat due to the depletion of the ozone layer by the greenhouse gases, flood, shortage of water due to climate change.
However, in Abraka, urbanization has also resulted in massive increases in problems such as obesity, township life, especially in modern urban slums of the developing world, are certainly immune to neither pestilence nor climatic disturbance such as floods, yet continue to strongly attract migrants. As an area is getting urbanized, there is the need to study climatic characteristics before they are completely militated by the modern trend of human population explosion, human and industrial activities as well as to get acquainted with its rural environmental conditions in relation to its rural surrounding centers. It is against this background that this research attempts to examine the effects of global warning in Abraka.
1.2 Statement of Problem
As the natural geographical setting and landscape of Abraka and its environs is rapidly being replaced by an agglomeration and clustering of both planned and unplanned building structures, its attendant consequences are enormous. The geometric increase in population, vehicular emissions from exhaust pipes, industrial discharges and increased use of power generating set due to erratic power supply by Power Holding Company of Nigeria (PHCN) all these lead to appreciable disturbance in the in the natural ecosystem of Abraka region, which in turn adversely affect the climate of Abraka.
One of the effects of man’s activities that is resulting to increase in temperature is based on the exercised through which changes in atmospheric composition particularly the CO2, Ozone and aerosols content of the atmosphere. There is unequivocal evidence that the CO2 content of atmosphere has been increasing over the years as a result of man’s use of fossil fuels, for energy. For instance the exploration of oil, has led to deforestation, the exploitation of oil has led to gas flaring in the southern part of Nigeria and that now exacerbate high temperature and lower humidity. The coastal location and presence of River Ethiope in Abraka helped to create humid condition and heavy amount of rainfall in Abraka, but the influence of the gas flaring (in neigbouring community such as Ebedei), fumes from generator sets etc. has shadow over this factor (Efe, 2002). Some other human activities in Abraka and its environ has in turn resulted to global warming. Some of these other activities include the use of generator sets, fumes from automobile vehicles and factory buildings, indiscriminate dumping of waste/refuse etc. Most of the farm products that are being produced at Abraka P.O, are being affected due to the adverse effect of human activities as most of the plant are being poorly produced as a result of too much high temperature in that part of Abraka. These substances (Fumes from factory building, generator sets, motor vehicles, tricycles and motorcycles) have also caused air pollution and also increased the temperature of the region there by causing Global Warming. This is as a result of increase in the numbers of building structures and warm air conditioners that adds warmth to the surroundings, much pollutes and radiate heat into the surrounding landscape and also turning of landscape into townscape also altered the natural environment. This alternation according to Efe (2002a and 2006) resulted in increased temperature of the urban canopy.
Similarly research efforts in the past years have focused mainly on education, economic activities, religion, political system, sporting activities, administrative divisions and other non geographical aspect of Abraka region. Virtually, as s result of intense research, it was discovered there has not been much emphasis laid on the effects of global warning in Abraka region, neither has interest been shown towards the idea.
In recent times there has been a call for periodic re-examination of the urban climate of tropical cities in order to have an update and compare the situation in these cities with that of other cities in the world (Lowry, 1998; Efe, 2004 and Adelekan, 2005). Based on these calls and with these numerous problems and the neglects associated with Abraka as an urban centre, the needs arises to carry out this study in order to find out how global warning has affected Abraka community in Delta State.
This study is also meant to truly point out the effects of global warning in Nigeria using Abraka region as a case study, including how urbanization and civilization has affected the climate of Abraka and its environs.
1.3 Aim and Objectives
The study is aimed at evaluating global warming effects in Abraka, and specific objectives are to:
1.5 Significance of the Study
The significance of the study lies in all over the effects of human activities resulting to global warning within Abraka. The effects and the importance of human activities on climate cannot be over emphasized. It is to this effect that the study is aimed at informing the people of Abraka the extent to which human activities have resulted to global warming.
Hence effort must be put in a place to control human activities in order not to affect the climate of Abraka negatively, as if the climate of the study area is continued to be affected by the excess of human activities. There may be excess of rainfall which in turn might cause flooding in the area or there might be over increase in the temperature of the area which will in turn affect not only agricultural activities but other activities also that human’s depend upon for survival. It is therefore hoped that the result of this research work will go an extra mile to control global warming caused by human activities resulting to depletion of the ozone layer which have greatly affected the climate of Abraka region. The findings will also provide useful background information to future research in the contribution of geography towards nations.
1.6 STUDY AREA
1.6.1 Location and Size
Abraka is located in the South-South zone of Nigeria. It is located in latitudes 050 471 and 050 501 North of the equator and longitudes 060001 and 060 081 East of the Greenwich Meridian. It is situated at the Eastern Bank of River Ethiope in Ethiope East Local Government Area of Delta State, Nigeria.
Abraka covers a total land area of 21.2 square kilometer (Ufuoma, 2000). In the North it is bounded by Orhionmwon Local Government Area of Edo State, in the South, it is bounded by Ughelli Local Government Area of Delta State, in the East, it is bounded by Ughelli North Local Government Area of Delta State and in the west, it is bounded by Okpe Local Government Area of Delta State.
Abraka region is located in the Benin lowland (Udo, 1987). Abraka is in the Humid Tropical Climate with very high temperature between months of November and April. It may be as high as 250c to 310c.
Rainfall throughout the year is due to its location in the Niger Delta with monsoon wind continually blowing from the Atlantic Ocean. The wet and dry seasons are noticeable with annual rainfall between 2000mm to 3000mm.
Table 1.1 Mean Monthly Rainfall Distribution (mm) in Abraka (1976-2005)
Source: Archive: Dept of Geography Weather Station: 1976-2005 (Efe, 2006)
Table 1.2 Mean Monthly Temperature Distribution (0C) in Abraka (1976-2005)
Source: Archive: Dept of Geography Weather Station: 1976-2005 (Efe, 2006)
Abraka as an urban area has experienced a rapid increase in size over the years, due to the presence of various administrative offices and governmental functions it performs both as the administrative and governmental functions. This is also as a result of the presence of the institution in the area. This attracts people from surrounding area, to itself, because of its employment opportunities and academic activities thus resulting in over-crowding, increased temperature, urban warming, among others leading to global warming.
1.6.2 Population of the Study Area
There have been increases in the population of Abraka since 2005 when it was declared an urban centre by the Ministry of Lands, Survey and Urban Development (MLSUD), Asaba-Delta State. The population of Nigeria as a whole has been on the increase in recent times (Mabogunje, 1980). He gave two reasons; which are natural growth in the urban population and migration from other parts of the world. This can be attributed to Abraka region as it is one of the rapid urbanization towns in Nigeria due to the presence of tertiary institution. The presence of tertiary institution that have different programmes and other economic activities has been one of the major pull factors attracting people into Abraka and this has led to population explosion which contributed immensely to rapid economic and socio-economic development of Abraka urban. Apart from population growth the town has expanded from small town to an urban centre today engulfing the surrounding of Abraka rural due to its rapid urban development.
The implication of these increase in size and population, is that it has led to population explosion in urban areas of Abraka which have in turn resulted in the alteration of the natural environment and its climate due to anthropogenic activates carried out in the area. This has in turn had adverse effect on the inhabitants of Abraka and its environs through global warming effects.
Abraka falls within the tropical environment that enjoys the tropical rainforest climate (AF) of Koppen in 1918 and the wet equatorial climate of Strahler in 1969. The climate is influenced by two masses; the tropical maritime air mass and tropical continental air mass. Abraka is region of the humid tropical climate with high temperature between the months of November and April with variation in temperature between 250c – 290c between April and October. The region of Abraka has an annual temperature of about 30.60c with a monthly mean temperature of 300c from September and 31.10c in June and July with an annual range in temperature between 30c and 50c. It is discovered in repeated studies that the average climatic rainfall in Abraka is about 2500mm annually. Abraka is placed into two seasons; the dry (Harmattan) and wet (rainy) season. However, Abraka experiences rainfall throughout the year owing to its location in the Niger Delta zone with the continual monsoon wind blowing from the Atlantic Ocean and also a continuous from shift in the Inter-Tropical Discontinuity (ITD) due to the movement of air masses.
The implication of these is that intense rise in temperature over the years have affected the inhabitants of Abraka through global warming effects.
Abraka is located on the equatorial rainforest which is evergreen forest and consist of three canopies of trees which are, the upper layer of which is about 60m tall, middle layer which is about 40m tall and the lower layer which is about 30m in height. The three major vegetation types in Abraka includes; the tropical rainforest belt, temperate grasslands and the grassland vegetation remains one of the key important factor which affect the climate of Abraka Region. Vegetation provides lumbering, medicinal purpose of Abraka region. The high amount of rainfall in Abraka aids the cultivation of crops like cassava and maize within the region. The influence of man has reduced the forest mainly to secondary growth (deciduous vegetation) due to agricultural practices and growing of various cash and food crops. This has in turn prone the environment direct sunlight which has resulted to intensive heating of the environment causing global warning due to lack of trees to act as shade and wind break.
The implication of these is that human activities have reduced the vegetation of Abraka to a secondary re-growth thereby exposing the environment to hazards such as intense temperature rise, flooding erosion, etc. which have in turn affected the inhabitants of Abraka through global warming effects.
1.6.5 Geology and Soils
Abraka is predominantly underlying sedimentary rock. Abraka lies in southern most sedimentary rock. Abraka lies in southern most sedimentary basis in Nigeria.
Abraka soil is acidic in nature. Abraka soil varies from coarse through medium to fine grained soils. The soils of Abraka can be said to be sandy loam. The colour of the soil is greenish brown to reddish brown and then to brown. The light grayish colouration characterizes the entire sandy portion of the soil, while the reddish brown colouration depicts the presence of ion oxide in the soil. This colouration depicts the availability of mineral matters and moisture. Abraka soil is poorly structured in relation to its type in terms of grain size, pore spaces which greatly influences the rate of percolation and capillarity, aeration and the rate of evaporation.
The implication of these is that human activities have exposed the soil to erosional activates and flooding making the soil inferity for agricultural acuities, etc. which have in turn affected the inhabitants of Abraka region who rely on farming for their source of livelihood.
1.6.6 Relief and Drainage System
Abraka and its environs are drained by two major rivers, River Ethiope and River Ovwuvwe.
Most communities in Abraka are located in the upland in between these Rivers. The drainage pattern of River Ethiope is dentritic in nature. These rivers serves as recreational and tourist centers, major sources of water to the populace, mining sites for sand stones, religious activities and agricultural activities just to mention but a few.
Abraka and its environs lies within the low land area of Nigeria, with 50m above sea level. Also, it is only about 45km from the coast of Nigeria. Abraka has a low relief of gentle hilly flat surface with an anticline nature i.e. having an elevation of less than or equal to 60 which in the north shell can also be linked ion classification with the interior coastal landmass of western Nigeria.
The porous nature of the Abraka soil coupled with the undulating landform absorbs much heat which radiates to the atmosphere thereby altering the climate of the area which may be responsible for high temperature in Abraka resulting to global warming.
1.6.7 Socio-economic Activities
The government of Ethiope East and Delta State at large has in recent time embarked on rehabilitation of existing, socio-economic, infrastructure such as roads, portable water, rural electrification, educational facilities, health facilities, stadium and other socio amenities. The government have areas such as revolutionalized changes and improvement in areas such as Education, Health, Agriculture, cooperative movement, commerce and market development, industrialization, Youth and sports development, etc. Town Unions, Private Individuals and associations, being part of voluntary agencies, have played active roles in the development of educational infrastructure, tourism and recreational facilities in the region.
In terms of transportation, the tricycle mode of transportation in Abraka has aided not only in the facilitation of movement of people and information but also in provision of employment, income and increases the standard of living of both motorcyclist, tricyclist and commercial transports.
In terms of commerce, the Abraka region entails sales of varieties of food crops which are produced locally such as yam, plantain, banana etc. alongside none food products. The physical structure of the Abraka market (Centre of Commerce) and other neigbouring stores being poorly planned has really affected the rate of commerce with regard to drainage, indiscriminate waste disposal at market site which has a resultant effect on the health standard of food crops for consumption sold in the market. This mismanaged waste produce heat which makes the environment inhabitable and thus results in the alteration of the climate which brings about global warming.
In terms of its settlement, Abraka is characterized with primary and secondary settlement. Primary settlement includes residential buildings, hospitals, health care centres and schools while secondary settlements are hostels, filling stations, factories etc. There is no doubt today that settlement pattern and characteristics has played a major role in the socio-economic development of Abraka region and have over the years boast the socio-economic activities of the region.
The people of Abraka region practice both subsistence and commercial agriculture in which food and cash crops are produced. They engage in mixed cropping and crop rotation farming method as their major type of agricultural practices. Over the years, agriculture has provided food, employment, sources of income, etc. to the inhabitants of Abraka region.
Generally speaking, the enormous emotion of poisonous gases and substances from motor vehicles, engines, tricycles etc into the atmosphere has polluted the environment and altered the climate of the area thereby resulting to global warming.
1.7 Scope/Delimitation of the Study
The scope of this study is restricted to the influence of urbanization on climate with emphasis on the effects of global warming in Nigeria using Abraka as a case study. The project is also restricted to some selected areas of study: these include Abraka P.O (Urban area of study), Ekrerejeta, Abraka Inland (rural area of study), Ajalomi, Erho, Oria, Urhuovie, Ugono and a control rural area (such as Umeghe and Urhagbesa).
However, this research work was limited by number of factors, amongst which are finance, time and physical constraints. But these constraints did not deprive the researcher from reaching dependable results.
1.8 Definition of Terms