Rainfall Pattern in Enugu State, Nigeria

Rainf on the whole Pattern in Enugu produce, NigeriaCHAPTER ONE1.0INTRODUCTIONEnugu tell is located in the to the southeastern part of Nigeria created in 1991 from the old Anambra pass on and the principal cities in the state argon Enugu,Agani,Awgu,Udi,Oji-River and Nsukka. The state sh ars b raises with Abia and Imo State to the south, Ebonyi State to the East, Benue state to the Northeast, Kogi state to the Northwest and Anambra state to the West.Enugu, the capital city of Enugu state, is most 21/2 driving hours away from Port Harcourt where coal shipments exited Nigeria. The backchat Enugu (from Enu Ugwu) means the top of the hill. The first European settlers arrived in the theater of operations in 1909, led by a British mining engineer, named Albert Kitson. In his quest for silver, he discovered coal in the Udi Ridge, compound governor of Nigeria Frederick Lugard took keen interest in the discovery, and by 1914 the first shipment of coal was make to Britain. As mining ac tivities increased in the ara, a unceasing cosmopolitan settlement emerged, supported by a railway system. Enugu acquired townsfolk status in 1917 and became strategic to Britain interests.Foreign businesses began to move into Enugu, the most renowned of which were John Holt, Kingsway Stores, British Bank of West Africa and United Africa Comp any(prenominal). From Enugu the British regime was able to spread its influence over the southern province of Nigeria. The colonial yesteryear of Enugu is today evidenced by the Georgian building events and move narrow roads within the residential bea origin anyy silent for the whites, an bea which is today called the presidential term Reserved Area (GRA).The state Government and the Local government are the levels of government in Enugu state and fool 17 Local Government areas. Economically, the state is pre dominantly rural and agrarian, with a substantial proportion of its working population meshed in farming, although vocatio n (18.8%) and services (12.9%) are also important. In the urban areas trading is the dominant occupation, followed by services. A small proportion of the population is also engaged in manufacturing activities, with the most pronounced among them located in Enugu, Oji, Ohebedim and Nsukka. The state boasts of a number of markets curiously at each of the divisional headquarters, prominent of which is the Ogbete master(prenominal) market in the State capital, Electricity supply is relatively steadfast in Enugu and its Environs. The Oji River power station (which characterd to supply electricity to all of Eastern Nigeria) is located in Enugu state. The state had a population of 3,267,837 great deal at the census held in 2006 (estimated at over 3.8 million in 2012), it is home of the Igbo of southeastern Nigeria.The intermediate temperature in this city is cooler to small-scale (60 degrees Fahrenheit) in its cooler months and gets warmer to hot in its warmer months (upper 80 degre es Fahrenheit) and very heartfelt for outdoor activities with family and friends or just for personal leisure. Enugu has good res publica- fetch and climatic conditions all year round, sitting at about 223 meters (732 ft) in a extravagantlyer coiffe sea level, and the commonwealth is easily d precipitate water supplyed during its wet seasons.The main(prenominal) temperature in Enugu state in the hottest month of February is about 87.16 0F (30.64 0C), while the lowest temperatures come on in the month of November, reaching 60.54 0F (15.86 0C). The lowest pelting of about 0.16 cuboidal cen dateters (0.0098 cu in) is normal in February, while the luxuriouslyest is about 35.7 cubic cen quantifyters (2.18 cu in) in July.The differences in altitude and relief create a broad variation in humour in various characters of the country. In places that are characterized as semi-arid zones, humor shows wide fluctuation from year to year and yet within seasons in the year. Semi arid regions receive very small, irregular, and unreliable rain (Workneh, 1987).The yearbook cycle of the climatology of the rainwater over tropical Africa and in particular over Nigeria, is strongly determined by the position of the mask Tropic Convergence Zone (ITCZ) (Griffiths, 1971). Variations in rainwater bod passim the country are the result of differences in elevation and seasonal transmits in the atmospheric pressure systems that control the persisting winds. The climate of Nigeria is characterized by high pelting variation (Yilma et al., 1994). In Nigeria, several regions receive rainwater end-to-end the year, but in some regions rainwater is seasonal and low making irrigation necessary (Alemeraw and Eshetu, 2009). Rainfall is the most critical and key variable both(prenominal) in atmospheric and hydrological cycle. Rainfall standards usually have spatial and blase variability. This variability affects agricultural production, body of water supply, transpo rtation, environment and urban mean, thus, the entire sparing of a country, and the existence of its people. Rainfall variability is assumed to be the main condition for the frequently occurring climate extreme events such as drought and flood. These innate phenomena affect badly the agricultural production and hence the parsimoniousness of the nation. In regions where the year-to-year variability is high, people often suffer great calamities due(p) to floods or droughts. Even though molest due to extremes of rainfall apprizenot be avoided completely, a forewarning could certainly be useful (Nicholls, 1980). Nigeria is one of the countries whose scrimping is highly dependent on rain-fed agriculture and also facing happen cycles of flood and drought. Current climate variability is already imposing a signifi fag endt challenge to Nigeria in global and Enugu in particular, by change food security, water and energy supply, poverty reduction and sustainable increment effor ts, as well as by causing natural imagination degradation and natural disasters. Recurrent floods in the past ca employ substantial kind-hearted life and property loss in many parts of the country.Methods of prevision of rainfall extreme events have often been based on studies of forcible make of rainfall or on statistical studies of rainfall season serial publication. Rainfall forecast is relevance to the agriculture sector, since it lends significantly to the sparing of countries give care Nigeria. In order to model and predict hydrologic events, one can use stochastic methods like time series methods. Numerous attempts have been made to predict behavioral pattern of rainfall using various techniques (Yevjevich, 1972 Dulluer and Kavas, 1978 Tsakiris, 1998). sentience about the characteristics of the rainfall over an area such as the source, quantity, variability, distribution and the frequency of rainfall is essential for the implication in utilization and associated pro blems. Assessing rainfall variability is practically useful in making decision, risk care and optimum usage of water resources of countries. Thus, it is important to obtain accurate rainfall forecast at various geographic levels of Nigeria and work towards identifying periodicities in order to help policy makers improve their decisions by taking into consideration the forthcoming and future water resources. In this read, univariate Box-Jenkins methodology to build ARIMA model are used for assessing the rainfall pattern in Enugu State based on data from Nigerian Meteorological Agency.1.1 brave out and ClimateWeather and climate over the earth are not constant with time they change on different time series ranging from the geological to the diurnal by dint of one-year, the difference between support and climate is a measure of time. Weather is what condition of the atmosphere over a short period of time and climate is how the atmosphere behaves over relatively dour period of time. seasonal worker and intra-seasonal time scales. Such variability is an inherent characteristic of the climate. The study of climatic fluctuations involves description and investigation of causes and effects of these fluctuations in the past and their statistical interpretation. some(prenominal) of the work done is about variability of the cardinal important meteoric parameters rainfall and temperature. Rainfall is a term used to refer to water falling in drops after condensation of the atmospheric vapor. Also rainfall is the resultant product of a series of complex interactions taking place within the earth-atmosphere system. Rainfall is only water that falls from the sky, whereas precipitation is any wet things that fall from the sky, which include snow, frozen rain.etc. Water in all its forms and in all its various activities plays a crucial role in sustaining both the climate and life. It is also a major factor for planning and focussing of water resource project and ag ricultural production. Even though Nigeria enjoys a fairly good heart and soul of rainfall, wide variability in its distribution with respect to space and time are responsible for the two extremes events (floods and droughts) (Yilma et. al,1994).1.2 Rainfall CharacteristicsRainfall varies with latitude, elevation, topography, seasons, distance from the sea, and coastal Sea-surface temperature. Nigeria enjoys the wet tropical climate type. Because of its emplacement just br new(prenominal)hood of the equator, also, Nigeria enjoys a truly tropical climate characterized by the hot and wet conditions associated with the movement of the inter-Tropical convergence Zone (ITCZ) northwest and south of the equator.While there is a general decrease in rainfall in Nigeria, the coastal area is experiencing slight increase. Apart from the general southward shift in rainfall patterns, the duration has also bring down from 50-360 (1993-2003) to 30-280 (2003-2013) rainy eld per year. This has created ecological destabilization and altered the pattern of the phytology belt especially in the northern part of the country. The rainfall pattern has also enhanced wind erosion and desertification, primer coat erosion and coastal flooding in the north, east and coastal areas of Nigeria respectively.The country experiences consistently high temperatures all year round. Since temperature varies only slightly, rainfall distribution, over space and time, becomes the private most important factor in differentiating the seasons and climatic distribution are however dependent on the two air masses that incur over the country. Their influences are directly linked to the movement of the ITCZ, north and south of the equator. The two air masses are the Tropical maritime(Tm) and the Tropical Continental (Tc). The former is associated with the moisture-laden south-west winds (south westerlies) which blow from the Atlantic Ocean, while the latter is associated with the ironic and dusty north-east winds (easterlies) which blow from the Sahara Desert.Conversely, with the movement of the ITCZ into the Northern Hemisphere, the rain-bearing south westerlies prevail as far inland as possible to bring rain fall during the wet season. The implication is that there is a pro presbyopiced rainy season in the far south, while the far north undergoes long dry periods annually. Nigeria, therefore, has two major seasons, the lengths of which vary from north to south. The mean annual rainfall along the coast in the south-east is 4000mm while it is 500mm in the north-east.Nigeria can, thus be broadly divided into the following climatic regionsthe humid sub-equatorial, in the southern lowlandsthe hot tropical continental, in the far norththe moderated sub-temperate in the high plateaus and mountainsthe hot, wet tropical, in the hinterland (the middle-belt )1.3 The main effects of RainfallTrends in rainfall extremes have enormous implications. Extreme rainfall events cause significa nt damage to agriculture, ecology, and infrastructure. They also cause disruption to human activities, injury, and loss of life. Socioeconomic activities including agriculture, power generating, water supply, human health, etc. are also very sensitive to climate variations. As a result, Nigeria economy is heavily dependent on rainfall for generating employment, income, and foreign currency. Thus, rainfall is considered as the most important climatic element that influences Nigeria agriculture. The severity and frequency of position of rainfall extremes events (meteorological, hydrological, and agricultural) vary for different parts of the country.Drought Drought is an subtle hazard of nature. It is often referred to as a creeping phenomenon and its impacts vary from region to region. Drought can therefore be difficult for people to deduct it is equally difficult to define, because what may be considered a drought in, say, Bali (six days without rain) would certainly not be consid ered a drought in Libya (annual rainfall less than 180 mm). Some drought years have coincided with EN events, while others have followed it. According to DDAEPA (2011) the trend of decreasing annual rainfall and increased rainfall variability is contributing to drought conditions in Nigeria Administration. The average annual rainfall patterns of Abuja for the periods 1999 to 2008 and 1984 to 1991 show two important trends. First, annual average rainfall has declined from the mean value by about 8.5% and 10% respectively. Secondly, the variability of rainfall shows an overall increasing trend, suggesting greater rainfall unreliability. These rainfall patterns have led to serious drought/flood episodes throughout the Administration. engorge Floods are known as the most frequent and devastating natural disasters in both developed and developing countries (Osti et al., 2008). Between 2000 and 2008 East Africa has experient many episodes of flooding. Almost all of these flood episodes h ave significantly affected large parts of Ethiopia. Ethiopias topography characteristics has made the country pretty dangerous to floods and resulting destruction and damage to life, economic, livelihoods, infrastructure, services and health system (FDPPA, 2007). Flooding is putting green in Ethiopia during the rainy season between June and September and the major type of flooding which the country is experiencing are flash flood and river floods (FDPPA, 2007).Like other regions of Nigeria, the issue of flood continues to be of growing concern in Enugu especially to peoples residing in lowlands, along or near the flood courses as well as village located at the foot of hills and mountains. Flood disasters are occurring more frequently, and having an ever more dramatic impact on Enugu in terms of the costs on lives, livelihoods and environmental resources. The topography of Enugu Administration mainly consists of mountains and hills with sop up slope, valleys, and river basins. Th e catchment characteristics accompanied with its large area coverage coupled with torrential rain fall during the short and long rainy season had been the main factors that contribute to the pervious flood events.Soil Erosion when soil moves from one location to another, it is referred to as soil erosion. The impact of rainfall striking the surface can cause soil erosion erosion is a concern for farmers as their valuable, nutrient rich top soil can be rinse away from rainfall. It can also weaken structures such as connect or wash out roads. Vegetation can decrease the amount of soil that is eroded during a rain. Erosion has been going on and has produced river valleys and molded hills and mountains. Such erosion is generally slow but can cause a rapid increase in the rate at which soil is eroded (i.e. a rate faster than natural weathering of bedrock can produce new soil). This has resulted in a loss of productive soil from crop and grazing land, as well as layers of infertile soil being deposited on formerly fertile crop lands the formation of gullies silting of lakes and streams, and land slips.1.4 Aim and Objectives of the studyThe main aim of this study is to analyze rainfall pattern in Enugu State using appropriate time series methods based on 15 years (January, 1999-Decimeber, 2013) data recorded at Nigerian Meteorological Agency (Enugu State).Specific Objectives1. To fit appropriate time series model to the monthly rainfall data.2. To forecast the rainfall pattern in the study area.1.5Data sourceThe monthly rainfall data in millimeters for the period January, 1999 to December, 2013, collected from the Nigerian Meteorological Agency (Enugu State) were used in the study. The site was chosen due to availability of relatively long series of meteorological data, the data is a secondary data.1.6 Significance of the breedingKnowledge of what happens to the water that reaches the earth surface will assist the study of many surface and subsurface water problem s, for efficient control and management of water resources. For a country like Nigeria, whose welfare depends very untold on rain-fed agriculture, a quantitative knowledge of water requirements of the region, availability of water for plant growth and supplemental irrigation, etc. on a monthly or seasonal basis is an essential requirement for agricultural schooling. In this regard, increased capacity to manage future climate change and weather extremes can also reduce the magnitude of economic, social and human damage and eventually, lead to better resistance. Assessing seasonal rainfall characteristics based on past records is essential to evaluate rainfall extreme risk and to contribute to development of mitigation strategies. Therefore, a reliable rainfall forecasting and assessing behavior at station, regional and national levels is very important.