Assessment of Ibadan Metropolis on Agricultural Land or Assessment of Urban Encroachment on Agricultural Land in Ibadan
Chapter One
AIM AND OBJECTIVES OF THE STUDY
The aim of this study is to assess Ibadan metropolis on agricultural land or assessment of urban encroachment on agricultural land in Ibadan between 2000 – 2020. The specific objectives of the study are to:
- To find out the extent of encroachment of Ibadan on agricultural land.
- To establish the effect of this encroachment.
- To proffer recommendations to this further encroachment.
CHAPTER TWO
CONCEPTUAL FRAMEWORK LITERATURE REVIEW
INTRODUCTION
This chapter reviews extant literatures on urban expansion. The first part reviews literatures on the definition of major concepts such as urban expansion, causes and consequences; urbanization, urban areas, and agricultural land. While the following part deal with Geographical
Information System (GIS), Remote Sensing; and the application of Remote Sensing and Geographical Information System GIS in Urban studies, growth and dynamics (detecting and monitoring, measuring and analyzing urban expansion).
CONCEPTUAL FRAMEWORK
Urban Expansion
Opinions are far from various on the concept of urban expansion. However, Manish, Aruna and Vivek (2012) define urban expansion as the horizontal or vertical outward extension of urban area over the adjacent agricultural land, which can be measured in term of acres of land or in terms of percentage (actual or percentage expansion respectively). The percent expansion refers to the percentage increase in the aerial strength of the urban center over a period of time.
According to Lin, Yohei, and Haihong (2003) Urban expansion is a natural process which consumes many hectares of prime agricultural lands from their surrounding every year, it comes about through the transformation of non-urban land (for example, farmland) into urban land (such as residences, parks, shops and factories). He further argued that such transformation is one way; once transformed, it is very difficult to return back to the original land use. Thus, urban expansion, like a diffusion process, is also temporal but it is not strictly continuous in time.
Minwuyelet (2004), also see urban expansion as a worldwide phenomenon or process that involves both the internal reorganization and outward expansion of the physical structure of urban areas which results in loss of prime agricultural farmlands and natural beauties. This process could be seen in the history of all urban centers, although the term (urban expansion) has become synonymous with the creation of visual blight and the loss of natural habitat, not all of its effects are negative. In its simplest form, it is nothing more than expansion which normally occurs away from the dense areas of existing urban development. The need for urban expansion continues to escalate as the population continues to increase (Almeida, 2020; Shishay, 2011).
However, European Environment Agency (2006), describes urban expansion as the physical pattern of low-density expansion of large urban areas, under market conditions, mainly into the surrounding agricultural areas where development is patchy, scattered and strung out, with a tendency for discontinuity. It is seen as „horizontal spreading‟ or „dispersed urbanization‟, uncontrolled and disproportionate expansion of an urban area into the surrounding countryside, forming low-density, poorly planned patterns of development and common in both high-income and low-income countries.
Urban expansion, which is synonymous with urban sprawl, is the extension of the attentiveness of people or urban settlement to the surrounding area whose functions are non-agricultural. It is characterized by a scattered population living in separate residential areas, with long blocks and poor access, often over dependent on motorized transport and missing well defined hubs of commercial activity (Unicef, 2012).
Glaeser and Kahn (2003) states that the reason urban expansion is perpetuated is due to the low cost of the agricultural land which is being converted. The transformation of low cost agricultural land accompanied with an increase in accessible transportation networks increases the ability of the workforce to move out from the densely developed, urban areas. This, in turn, creates new areas for economic expansion and the overall increase of the tax base for local government.
CHAPTER THREE
THE STUDY AREA AND METHODOLOGY
INTRODUCTION
This section discusses the study area and the various methods that were employed in generating data for the study. The section also explained the types and sources of data, tools and procedure for data analysis using Remote Sensing and GIS in the study area.
STUDY AREA
Historical Background
Ibadan, coined from the phrase “Eba Odan”, which literally means ‘by the edge of the meadow’, came into existence in 1829, during a period of turmoil that characterized Yorubaland at the time. It was in this period that many old Yoruba cities such as old Oyo (Oyo ile), Ijaye and Owu disappeared, and newer ones such as Abeokuta, new Oyo (Oyo atiba) and Ibadan sprang up to replace them. According to local historians, Lagelu founded the city, and was initially intended to be a war camp for warriors coming from Oyo, Ife and Ijebu. As a forest site containing several ranges of hills, varying in elevation from 160 to 275 metres, the location of the camp offered strategic defense opportunities. Moreover, its location at the fringe of the forest (from which the city got its name) promoted its emergence as a marketing centre for traders and goods from both the forest and grassland areas.
In 1852, the Church Missionary Society sent David and Anna Hinderer to found a mission. They decided to build the mission and a church in Ibadan when they arrived in 1853.
Ibadan thus had initially begun as a military state and remained so until the last decade of the 19th century. The city-state also succeeded in building a large empire from the 1860s to the 1890s which extended over much of northern and eastern Yorubaland. It was appropriately nicknamed idi Ibon or “gun base”, because of its unique military character.
Population
With a population of over 6 million, it is the third most populous city in Nigeria after Lagos and Kano; it is the country’s largest city by geographical area.
The town’s morphology has changed over time to assume its present status and the accompanying land use problems, as experienced in similar medium sized urban centers in Nigeria continue to grow.
CHAPTER FOUR
RESULTS AND DISCUSSION
INTRODUCTION
This chapter dwells on the presentation and analysis of result obtained from the research analysis; the objectives of this study formed the basis of all the analysis carried out in this chapter. The results are presented in figures 4.1, 4.2, 4.3 4.4; and tables 4.1, 4.2, 4.3. and 4.4. The presentation and analysis of the data have been carried out under the following subthemes; land use and land cover classes; extent, percentage and rate of land use land cover change; spatial loss of agricultural land to other land uses; and the rate of agricultural land conversion to urban built – up (urban expansion) trend, pattern and rate of land use land cover change.
CHAPTER FIVE
SUMMARY, CONCLUSION AND RECOMMENDATION
INTRODUCTION
This chapter describes the summary of the major findings of this study, conclusion derived from the findings and recommendations for effective management and reducing the impact of urban expansion particularly on agricultural land in the study area and the state at large.
SUMMARY OF THE MAJOR FINDINGS
This research provide insight on the impact of urban expansion of agricultural land in Ibadan using Remote Sensing and GIS. Attempt was made to capture as accurate as possible the five major land uses types in the study area as they change through time. The study used Remote Sensing and GIS as an analytical tool with satellite images used for mapping and quantifying the land use types, rate and extent of urban growth, spatial loss and conversion of agricultural land to other land use and urban expansion within the study period.
As shown from the classified land use classes, land use types had changed significantly over the period of more than two decades (2000 – 2020). The statistics indicated that the growth rate of built up area occupied the largest share among land use categories especially at the expense of agricultural land. It shows a rapid decline in agricultural land between 2010 and 2020 while the period between 2000 and 2010 witnessed relatively slow decline. The lost agricultural land between these periods was converted to urban land use (built up and bare surfaces).
Agricultural land which has the highest coverage with 148.63 km² (65.36%) in 2000, 135.57 km² (59.62%) in 2010 and 107.18 km² (47.14%) witnessed decreasing trend throughout the study period (2000 – 2020). It changed by -41.45 km² (-27.89%) with an annual change rate of -1.73km² (-1.16%) and lost 1.81 km2 (0.80%) to urban expansion within the same period. Natural vegetation also reduced gradually over the study period from 23.54%, 15.97% and 11.86% in 2000, 2010 and 2020 respectively. This gradual reduction of agricultural land and natural forest can be attributed to the constant conquest by built – up land and bare surfaces.
The built-up area expanded from 17.5km² in 2000 to 32.00km² and 65.09km² in 2010 and 2020, the extent of the change within the same period was 14.42km² (82.09%), 33.09km² (103.42%) and 47.52km² (270.40%). It also expanded at an annual rate of 1.60km² (9.12%) between 2000 and 2010; 2.21km² (6.89%) between 2010 and 2020; and 1.98km² (11.27%) within the study period (2000 – 2020). This gradual expansion was at the expense of agricultural land and is also attributed to the creation of a local government area, sitting of federal and military institutions, rapid physical, commercial development of the study area as well as the significant rise in socioeconomic indices and population growth.
The GIS based analysis of urban expansion over the demographic change and land use modifications has also indicated that urban growth has basically taken place haphazardly on agricultural land because it is the suitable available land. This means land use has been changing from predominantly agricultural uses to non-agricultural uses, such that provision of residential and recreational space, transportation facilities, and industrial space is clearly dictated by the urbanization phenomenon.
CONCLUSION
This research work showcases the ability of GIS and Remote Sensing in analyzing spatialtemporal dynamics of urban growth. Ibadan has emerged from being predominantly rural area three decades ago to a city with an appreciable urbanization level. The result has shown that the area has lost quite significant portion of its agricultural land to urban expansion. Built – up has gained 28.63% of the total coverage over the study period. Therefore, there is a need to an understanding of structural urban dynamics in order to have absolute foundation for the formulating sound and effective urban policies. Such policies must be contemporary to turn potential crises into opportunities as failure maybe too devastating. Hence, the challenge is the sustainability of agricultural land (and in extension agricultural activities) in the face of very rapid declining agricultural land and urbanization. This feat can be achieved via the integration of agricultural landscapes into urban land use planning systems and as crucial part of urban development since urban growth and expansion is inevitable.
RECOMMENDATIONS.
The result of this work has shown that there had been remarkable reduction in agricultural land and a resulting increase in urban built up. In fact, the area has lost about 43.59% km² of its prime agricultural land to urban expansion in less than three decades. In view of the rate of development that is going on at present and the likely ones in the future with due consideration of the conversion rate of agricultural land to urban built up, the following are therefore recommended;
- Population influx has been attributed as one of the major causes of urban expansion in the study area especially from the surrounding rural areas. Hence adequate social amenities should be incorporated into rural planning framework to improve living conditions in the rural areas so that the rate of emigration will be reduced and thereby checking the expansion of the city on agricultural land.
- There is need to control urban spreading to agriculture land as this will have serious repercussion on food production. Although urban expansion cannot be stopped, with proper management and planning it can be directed in a desirable and sustainable way.
- Remote Sensing and GIS techniques should be incorporated as a monitoring system which will enable planners and decision makers to adequately plan and control urban expansion effectively in a spatiotemporal dimension.
- Proactive measure should be taken by all stakeholders the study area towards a better understanding of the changing pattern of landuse of the area so as to be better equipped in order to manage various environmental challenges that might be associated with urban expansion.
- Impact of population growth and urban expansion on agricultural land is a continual phenomenon; this research is therefore not an end to the issue of loss of agricultural land to urban expansion. Therefore that further studies into spatiotemporal pattern of urban expansion, the resulting environmental effects is recommended.
REFERENCES
- Abumere, S.I (2003) Urbanization. In Africa Atlases: Atlas of Nigeria, pp. 88 – 89. Paris: Le Editions J.A
- Adebayejo, A.T. and Abolade, O. (2006) Analysis of Spatial changes in Ogbomoso City; Journal of the NITP, Vol. 19 No 1, 40th Anniversary issue, 35-47.
- Adediji A. and Ajibade L.T. (2008) The change detection of major dams in Osun state, Nigeria using Remote Sensing and GIS techniques. Journal of Geography and Regional Planning. 1(6), 110-115
- Adem Siraji and Mezgebe T. Micheal, (2006) Impact assessment on urbanization and development of infrastructure on the livelihood of the displaced farmers from their farmland, Tigray Regional Environmental Protection, Land Administration and Use Authority, Mekelle, Addis Ababa
- Adesina, F.A; W.O. Siyanbola; F.O. Oketola; D.A. Palermo; L.O. Ojo and A.O. Adegbulugbe (2010) Potentials of agroforestry for climate change mitigation in Nigeria, some preliminary estimates; Global Ecology and Biogeography Letters, Vol 8, 163 – 173.
- Adeshina, F.A., (2020) Geoinformation and natural resources exploitation in Africa; United Nations Economic and Social Council. Paper delivered in Fourth meeting of the committee on Development Information, Addis Ababa.
- Agboola, T. (2004) “Readings in Urban and Regional Planning” Published by Macmillan Nigeria Limited, Ibadan, Oyo State, Nigeria. Pp. 179
- Akhmat,G and Y. Bochun (2010) Rapidly Changing Dynamics of Urbanization in China: Escalating Regional Inequalities and Urban Management Problems, Journal of SustainableDevelopment, 3(2) (2010), 153-158.
- Albert, O, Edmund, C.M. and Yaw, A.T. (2006) Use of Remote Sensing and GIS Techniques as a Decision Tool in Land Administration: The Case Study of Lagos, Nigeria. Promoting Land Administration and Good Governance. Journal of 5th FIG Regional Conference, Accra, Ghana March 8-11, 2006
