Spatial Growth Assessment with Remote Sensing Data for Central Nigeria

JOURNAL OF AGRICULTURE & SOCIAL SCIENCES ISSN Print: 1813–2235; ISSN Online: 1814–960X 09–058/SBC/2011/7–1–1–6 http://www.fspublishers.org

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Spatial Growth Assessment with Remote Sensing Data for Central Nigeria DAVIDSON S.A. ALACI1, FRANKA A. AMUJABI†, ADAMS N. BABA AND OGBAJE DANIEL‡ Department of Urban and Regional Planning, Federal Polytechnic Idah, P.M.B 1037, Kogi State, Nigeria †Corporate Quality, Health, Safety and Environment and Security Management Unit, Julius Berger Nigeria Plc Abuja (FCT) Nigeria ‡Department of Architecture, Federal Polytechnic Idah, Kogi State Nigeria 1 Corresponding author’s e-mail: [email protected]

ABSRACT Remote sensing data are reliable basis for making predictions about growth. Present study was aimed to analyze the spatial growth through remote sensing (RS) data to assess urban expansion in Kogi state, central Nigeria. This study integrated LandSat TM of 1987, LandSat ETM 2001 and Nigeria Saturday, 1 2005 satellite imageries and came out with a comprehensive land cover change over the period, 1987-2005. It used ILWIS 3.1 for image processing, which were classified into these land uses; bare surface, built-up area, cultivated area, natural vegetation and water body. The analysis shows that between, 1987 and 2005 the size of the built-up area (settlement) increased by 9.97 km 2 from 0.34 km 2, with over 162% growth rate indicating a rapid rate of physical development. Arising from this is the substantial ecological resources increasingly being lost due to the physical expansion. Other problems include flooding, over-stressed facilities and environmental pollution. The study conclude by recommending the increased use of RS data in urban management because it is one of the best approach to making inventory and to map, monitor urban growth and model the natural environment. © 2011 Friends Science Publishers Key Words: Remote Sensing; Urbanization; Growth; Land Cover Change and Lokoja

INTRODUCTION The process of outward expansion of settlements (towns & cities), urbanization is driven by a number of interconnected development of alteration cutting across economic, demographic, political, industrial and social specialties. When, properly managed, this process makes urbanization an essential building mass of prosperity, accounting for 50-80% of National Gross Domestic Product (GDP) of most countries (Alaci, 2008). It is the increasing contribution of urban centers to the Gross Domestic Product (GDP) of countries worldwide that has made urban development an attractive vehicle for economic improvement and poverty alleviation. This is why urbanization is increasingly becoming the norm and as Alaci (2008) noted, cities are regarded as the most efficient agents of production. According to the United Nations (UN) projections, some 97% of all world population increase between 2000 and 2030 will be in urban areas and almost entirely within the developing countries, enduring a prototype recognized in 1950 (Getis et al., 2004). Well managed urban growth and development can contribute not just to economic advancement, but also to reduce poverty and improved quality of life for all citizens, including the poor (Un-Habitat, 2002). The resultant dysfunctional

urbanization attributes have high cost, making more difficult the economic growth needed to improve living standards. Nigeria as an important crude oil exporter and the oil boom from 1973 to 1979 generated an intense social and economic activities in large urban centers in Nigeria (Abiodun, 1985). Lokoja is an urban centre in central Nigeria. The city has experience series of political status change within the last 50 years; first as a provincial capital, then later (when provinces were scrapped in Nigeria) Local Government headquarter and now a State capital. Consequently infrastructure and amenities are almost continuously under intense pressure, stress and in short supply. Erratic and unreliable power supply and water supply, long queues at public water point, long distance trekking in search of water, traffic congestion are among the many manifestations of infrastructure inadequacies. In many instances urban planning and management decisions have been based on casual observation and demographic data analysis. Since qualitative measurements are often subjective, quantitative measures are the only alternatives. Remote Sensing (RS) Data are scientific measures that can provide a more vivid and reliable information on urban expansion. Remote sensing data yield graphical and quantitative elements whose qualitative analysis can be relied upon for planning and management

To cite this paper: Alaci, D.S.A., F.A. Amujabi, A.N. Baba and O. Daniel, 2011. Spatial Growth Assessment with Remote Sensing Data for Central Nigeria. J. Agric. Soc. Sci., 7: 1–6

ALACI et al. / J. Agric. Soc. Sci., Vol. 7, No. 1, 2011 decisions. This paper therefore uses RS Data to measure the rate of growth of Lokoja urban system. The purpose is to examine the nature of land use/cover change in Lokoja ensuing from spatial growth; recognize key environmental challenges occurring from the spatial growth and make informed recommendation to solve the issues arising thereof. This study is hinged on the multiple nuclei theory owing to the fact that Lokoja has multiple CBD and each having growth pole to development (Hammond, 1979; Waugh, 2000). Remote Sensing (RS) is a technology that offers a significant opportunity to help improve effectiveness of urban management, to help guide growth and development and to help maintain and improve quality of metropolitan environments. Lillesand and Kiefer (1994) defined RS as the science and art of obtaining information about an object, area or phenomenon through the analysis of data acquired by the device that is not in contact with the object, area or phenomenon under investigation. According to Campell (1996), RS is the practice of deriving information about the earth’s land and water surfaces using images acquired from an overhead perspective, using electromagnetic radiation in one or more regions of the electromagnetic spectrum reflected or emitted from the earth’s surface (Campell, 1996). For the purpose of this study, Campell’s definition shall suffice. Estes (1974) noted that RS provides a means of discerning physical changes in the distribution of activities, which in turn are related to social and economic changes within the system. Balzerek (2001) used Ikonos satellite data for monitoring, classification and evaluation of urbanization processes in Africa; highlighting the improvement in the classification of urban areas by using high resolution imagery. The method allows quick monitoring of the urbanization process to be linked to demographic and socioeconomic background information. Clark and Pellikka (2005) adopted the multispectral SPOT XS satellite images with the period under observation from 1987-2004 in monitoring land use change. The urban growth of Voi, soil erosion processes, land cover and land use change, development of infrastructure and condition of the indigenous forest remnants were studied by the authors in the Taita hills, SE-Kenya using the images mentioned earlier.

Table I: Population Projection Lokoja Town 1991 2004 2014. + Adankolo 2,926 5,208 ↓ 8,332 ↓ + Lokongoma 618 1,100 ↓ 1,760 ↓ + Felele 716 1,274 ↓ 2,038 ↓ + The rest of Lokoja 39,524 70,352 ↓ 112,563 ↓ * Ganaja 309 550 * 880 * *Otokiti (Army Barracks) 550 979 * 1,566 * Total 79,463 127,139 * Researcher’s estimate + National Population Census 1991 ↓ Researcher’s projection of 6% based on growth rate (Ecoplan projected growth rate)

Table II: LandSat TM Bands (Lillesand & Kiefer, 1994) Band 1 2 3 4 5 6 7

Wavelength (µM) 0.45 - 0.52 0.52 - 0.60 0.63 - 0.69 0.76 - 0.90 1.55 - 1.75 10.4 - 12.5 2.08 - 2.35

Spectral Locaton Blue Green Red Near Infra-Red Mid Infra-Red Thermal Infra-Red Mid Infra-Red

Table III: Image Processing

Images; LandSat TM, LandSat ETM, NigeriaSat-1 Image Georeferenced. Created Sample Set. Image Classification. Statistical Charting.

LandSat TM 1987: LandSat TM sensor provides several improvement over the MSS (Multispectral Scanner) including; higher spatial resolution and radiometric resolution, finer spectral bonds with seven (as opposed to four in MSS) Spectral band (Table II). Thematic Mapper data are collected using a 30 m ground resolution cell except for the thermal band with 120 m resolution. The image was acquired on the 10th of December, 1987. LandSat ETM 2001: LandSat ETM has the same seven spectra bands and the same spatial resolution as LandSat TM. The ETM major improvement over the TM was the design of the detector, which permits the data for the branch to be automatically co-registered as they are acquired. This image was taken on the 17th November, 2001 (Table III).

MATERIALS AND METHODS Lokoja is medium-sized urban centre in central Nigeria. It is both the administrative and commercial capital of Kogi state, the most centrally located state in Country. The state is located between Latitude 70 47’ N and Longitude 60 46’E. The annual growth rate of 2.5% raised the population by 1996 to 49,258. The projection in this paper is based on the estimated annual growth of 6% used in Ecoplan projection cited in Tolushe (2003). This is in recognition of the diverse socio-economic functions associated with Lokoja (Table I).

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GROWTH ASSESSMENT WITH REMOTE SENSING / J. Agric. Soc. Sci., Vol. 7, No. 1, 2011 ETM 2001; NigeriaSat-1 2005. Computer hard ware was used in accessing the images, while ILWIS 3.1, Microsoft Excel and Microsoft Word (Software) were used for the processing of the images. Image georeference: Since every point on earth has location. The images were Georeferenced to bring out only the study area with coordinates in Latitude and Longitude and Universal Transverse Mercator (UTM) With minimum range as Lat.7045’ 27 56”N; Long 6041’ 55.64”E UTM (246194.77, 858194.66) and Maximum range as; Lat.7051’ 04.34”N Long 6045’ 36.58”E UTM (253022.01, 868508.26). The images were Georeferenced with essential annotations such as Title, Scale, Legend and North direction. LandSat TM and ETM with band 4, 3, 2 and channel 3, 2, 1 were used, while NigeriaSat-1 has the same band with the LandSats, but different channel 1, 2, 3 (Green, Red, InfraRed). In other words, NigeriaSat-1 has a different scale from LandSat TM and ETM because of their different resolutions. The images were in False Color Composite (FCC). Sample set: Sample set was created in other to train the computer to recognize certain feature as a particular class. Image classification: To further process the images, pixels were assigned to categories based on their reflectance characteristics. With range of 28, from 0 (black) to 255 (white), having digital number of 8 bits. In classifying the sample set, the maximum likelihood classification method was adopted with supervised classification based on the knowledge of the study area. For a better understanding and representation of changes that has taken place in the study area, statistical data were extracted base on the figures from the classified sample set; land area for each class was converted to Sq. km (km2), tables for the images with their classes drawn and bar charts plotted. The analysis, interpretation, results and discussion of results are presented in the next section of this study. The images (Landsat TM, ETM & NigeriaSat-1) were classified using ILWIS 3.1 into their various land use; the Bare Surface, Built-up Area, Cultivated Area, Natural Vegetation and Water Body. Figs. 1, 2 and 3 show the classification of the study area and digitized image of the built-up area from 1987-2005 is presented. From the images, each classified land use has an area covered in square kilometers (sq km). With this, tables of classes and area covered were used to draw up the bar chart showing the variance in land use along side with percentage (%) of each land use. This was done to further simplify the interpretation of the images (Table IV-VIII).

Table IV: Derived Classified Landsat TM 1987 Variance in Land Use Class Bare Surface Built-up Area Cultivated Area Natural Vegetation Water Body

Area (sq km) 0.25 0.34 18.22 42.21 2.8

Percentage (%) 0.39 0.53 28.55 66.14 4.39

Table V: Derived Classified Landsat ETM 2001 Variance in Land Use Class Bare Surface Built-up Area Cultivated Area Natural Vegetation Water Body

Area (sq km) 2.43 9.17 37.25 10.13 4.60

Percentage (%) 3.82 14.42 58.59 15.93 7.24

Table VI: Derived Classified NigeriaSat-1 2005 Variance in Land Use Class Bare Surface Built-up Area Cultivated Area Natural Vegetation Water Body

Area (sq km) 2.52 10.31 38.18 7.90 4.40

Percentage (%) 3.98 16.29 60.31 12.48 6.94

Table VII: Land-Use Changes and Growth Rate between, 1987 and 2001 Size in 1987 Size in 2001 Newly created (%) (km2) Land- use Growth (km2) Bare Surface 0.25 2.43 2.18 62.3 Built-up Area 0.34 9.17 8.83 185.5 Cultivated Area 18.22 37.25 19.03 7.5 Natural Vegetation 42.21 10.13 -32.08 -5.4 Water Body 2.8 4.6 1.8 4.6 Source: Landsat TM 1987 and Landsat 2001 Land-use

Table VIII: Land-Use Changes and Growth Rate between, 2001 and 2005 Size in 2001 Size in 2005 Newly created (%) (km2) Land- use Growth (km2) Bare Surface 2.43 2.52 0.09 0.9 Built-up Area 9.17 10.31 1.14 3.1 Cultivated Area 37.25 38.18 0.93 0.6 Natural Vegetation 10.13 7.90 -2.23 -5.5 Water Body 4.6 4.40 -0.2 -1.1 Source: Landsat ETM 2001 and Nigeriasat-1 2005 Land-use

It is one of the latest satellites launched into space by Nigeria in 2003. The NigeraSat-1 has a spatial resolution of 32 m and its spectral location is Green, Red and infra Red. The image was taken on the 11th November, 2005. The source of the images is from National Space Research and Development Agency (NASRDA) Abuja. The Method used in processing the images in this research work is as follows: The images used are LandSat TM 1987, LandSat

RESULTS AND DISCUSSION Lokoja town is experiencing tremendous population growth and this is particularly visible from increase land use conversion. The population of the ‘growth poles’ of Lokongoma, Adankolo, Ganaja and Felele appears to also be increasing. The 1987 LandSat TM image classification of the

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ALACI et al. / J. Agric. Soc. Sci., Vol. 7, No. 1, 2011 Fig. 1: Landsat TM 1987, Image of the study area

Fig. 3: Nigeriaset-1 Imae 2005 of the Study area

Source: National space research development agency (Nasrda) Abuja

Source: National space research development agency (NASRDA) Abuja

expansion are changes in land use. This is expressed in the reduction of Natural Vegetation by 32.08 sq.km (50.12%) and increased Cultivated Area by 19.03 sq.km (30.04). Based on the 2005 NigeriaSat-1 image classification the Built-up Area expanded by 1.14 sq.km (1.87%) and cultivated area by 0.93 sq km (1.72%), while Natural Vegetation land use shrunk by 2.23 sq km (3.45%). This was found to be consistent with earlier studies like Alabi and Ufuah (2007), who examined the rate of farmland conversion to built environment along the bank of River Niger in Lokoja as well as Alabi (2009), where urban sprawl pattern and development was measured. The two studies had relied on satellite imageries to draw conclusions on both the rate of farmland conversion and sprawl expansion. However, specific focus on environmental implications was not part of these studies. Aggregating the Commercial/Industrial, residential, Public and semi-Public Land use under the Built-up Area, The effective urban area of Lokoja covers such areas as Lokongoma, Felele, Gadumo and Otokiti (Army Barracks), which were before now rural suburb localities. Jinadu (2004) work on Urban Expansion in Abuja, gave the difference in Area Extent and the growth rate of each land-use. His formula was adopted.

Fig. 2: Landsat ETM (2001), Image of the study area Source: National space research development agency (NASRDA) Abuja Nigeriasat-1, 2005

study area (Table I) shows that urban growth/urbanization was minimal in terms of settlement (Built-up Area) only 0.34 sq.km or 0.53% of the total land area. The land use was more of natural Vegetation covering as much 42.21 sq.km (66.14%). The Built-up Area from the image was principally the old township (i.e., the native town) made up of Kabawa, Karaworo, Cantonment, Kpata, Marine and Adankolo. The 2001, Landsat ETM image classification (Table II) gives a clear cut change in the Built-up Area, which increased to 9.17 sq.km (14.42%), with expansions in land area reaching 8.83 sq.km (13.89%). Although density has became highest in the native town, noticeable expansion is taken place in the outer periphery of the city along Ajakuta and Okene road. These expansion areas are made up of Phase I and II, Worker’s Village, 200 Housing Unit. Commissioner’s quarters, Confluence Beach Hotel, 500 housing Unit, Colonel Danladi Zakari Housing Estate. The implication of this growth and consequent outward

r = ∆A x 100 nA0 Where: r = Growth rate. ∆A = Change in area extent between 1987 and 2005. n = Number of years (interval between 1987 & 2005) A0 = Area extent of the base year (1987). Loss of natural resource: Perhaps, the most direct repercussion arising from the physical growth of Lokoja is the loss of bio diversity, ecological and or environmental resources. This is because a reduction in vegetal cover has implication on cumulative plant and animal kingdom. Absence of plant for example translates to a reduction in the

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GROWTH ASSESSMENT WITH REMOTE SENSING / J. Agric. Soc. Sci., Vol. 7, No. 1, 2011 of the environment. In tune with this, this study has demonstrated in very scientific and reliable way, how remote sensing data can be used in monitoring urban growth. It has shown that Remote Sensing provides unique sets of data about many important aspect of urban growth and the accompanying environmental change in which adequate measures can be taken. The growth rate of Lokoja and its implications have been succinctly communicated devoid of ambiguities even to an environmental conservation neophyte. It is recommended that Nigeria TOPREC should increase the knowledge content of the various institutions responsible for the training of town planners with issues on application of remote sensing knowledge. Associations like the Nigerian Society of Remote Sensing should harness the available Remote Sensing opportunities and capabilities in the Nigerian environment for the benefit of the country. Associations like the Nigerian Society of Remote Sensing should harness the available Remote Sensing opportunities and capabilities in the Nigerian environment for the benefit of the country. Monitoring systems through reliable data like Remote Sensing should be adopted as activities which will enable planners and decision makers arrest errors before they occur, as well as manage changes in dynamic environments. Adopt the use of Remote sensing data as an integral part of the urban planning and management tool. Government should give adequate priority to the discipline of space technology in our tertiary institution so as to prepare skilled and professionals that will carry out government project of monitoring urban growth and other related issues. Members of the Nigerian Institute of Town Planners (NITP) and the Town Planners Registration Council of Nigeria (TOPREC) should increase the knowledge content of the various institutions responsible for the training of town planners with issues on application of Remote sensing Knowledge.

oxygen supplied into that environment. Loss of vegetal cover, more paved surfaces, use of corrugated iron sheet together with increase in built up area among others result in higher surface run off. Where, drainage and storm water ways are not properly maintained this can lead to flooding and sheet erosion. It also leads to less infiltration and hence reduction in ground water recharge. In addition to this is the loss of farmlands; areas hitherto used for crop production including rice fadama areas have all given way to buildings. This has meant farmers traveling longer distances to establish farms and the intensification of plots in close vicinity. Intensification of agriculture has implication on soil quality susceptibility to erosion. Flooding: Due to the rapid urban growth of the town, there are many un-planned rural-urban fringe within Lokoja. This un-controlled land use has resulted in illegal construction of houses and construction on drainage channels and other areas not fit for residential construction. This is common in places like Felele, Adankolo and Sarikin Noma areas among others. Over-stressed facilities: The stress can be displayed on the traffic congestion usually along the Murtala Mohammed Express Road, this congestion is associated with the fact that the road over the years has become too narrow, with no space enough for cars to pull off the road (i.e., park) and the space for pedestrian (walk way) is almost disappearing. This congestion is further compounded when luxurious buses and tankers travel through the road. There are many un-planned structures that exist around Lokongoma, Science school area all further diminishing available space for traffic flow. Environmental pollution: Environmental Pollution in Lokoja arises mainly from the indiscriminate disposal of waste. With the rapid growth of Lokoja the immense increase in waste generation and refuse comes largely from domestic (residential) and market places (commercial) resulting in heaps of un-collected waste as seen around Lokoja. These wastes have largely become problematic and a case of eye sore. Waste generation grows with increase in population and where effective planning and urban management is absent, indiscriminate disposal results. This is the present state of many parts of Lokoja city.

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CONCLUSION The sustainability of the environment is a matter of necessity; it has been recognized at the global level with many international discuses on the environment, which includes the Millennium Development Goal No. 7, Targets 1 and 2; integrate the principles of sustainable development into country policies and programmes and reverse the loss of environmental resources; Reduce biodiversity loss, achieving, by 2010, a significant reduction in the rate of loss. This therefore calls for adequate measures to be taken to address the challenges associated with urban growth and population explosion among others. Space technology is unanimously adopted as a tool for the sustainable development

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Jinadu, A.M., 2004. “Urban Expansion and Physical Problems in Abuja. Implications for the National Urban Development Policy. J. Nigerian Inst. Town Planners, XVII(1): 15-27 Lillesand, T.M. and R.W. Kiefer, 1994. Remote Sensing and Image Interpretation. John Wiley and Sons Inc Tolushe, S.A., 2003. An Analysis of Physical Changes in Lokoja Town, 1991-2003. Final year dissertation. Department of Urban and Regional Planning, Federal Polytechnic Idah, Kogi State, Nigeria Un-Habitat, 2002. Sustainable Urbanisation. Achieving Agenda 21, Nairobi, Kenya Waugh, D., 2000, Geography; An Integrated Approach. Nelson House, United Kingdom (Received 01 October 2009; Accepted 08 May 2010)

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