In: Wagner W., Szekely, B. (eds.): ISPRS TC VII Symposium - 100 Years ISPRS, Vienna, Austria, July 5-7, 2010, IAPRS, Vol. XXXVIII, Part 7B 
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however, is sometimes weak (Jensen, 2005). In heterogeneous 
areas, such as residential areas, it has been shown that 
classification accuracies may improve even as spatial resolution 
decreases (Cushnie, 1987). This occurs due to the potentials of 
urban features to blend together to form composite distinctive 
“urban signals” that can be distinguished from other landcovers. 
In this study, the capabilities of three satellite imageries 
including Landsat, NigeriaSat-1 and SPOT-XS for landuse 
studies are evaluated with a view to amplifying the 
understanding of their specific potentials, advantages and 
limitations for environmental studies. This is borne out of the 
growing recognition of the need to develop “appropriate 
technology” for developing countries to enable researchers 
based in these countries to accomplish desirable level of 
sophistication in earth’s resources analyses even with their 
limited access to spatial data. 
2. THE STUDY AREA/ LOCATION EXTENT 
The study area is made up of Ekiti west, Ado-Ekiti, 
Irepodun/ Ifelodun and Ekiti south-west. Local government 
areas in Ekiti State of western Nigeria (Figure 1). The State lies 
within Longitudes 4° 5 and 5° 45 East of the Greenwich 
Meridian and Latitudes 7° 15 and 8° 5 North of the Equator. It 
is about 6,353 square kilometers in size. It is bounded in the 
north by Kwara and Kogi States, in the West by Osun State and 
Ondo State in the East and in the South. The State has 16 Local 
Government Areas. By 1991 Census, its population was 
1,647,822. The estimated population upon its creation on 
October 1 st 1996 was 1,750,000 with the capital located at Ado- 
Ekiti (Ekiti Investors Handbook, 2002). The current estimated 
population based on 2006 census, was 2384212 million people 
(NPC, 2006). 
Figure 1: Map of Ekiti State and the LGAs used for the study 
The State is mainly an upland area, rising generally around 
250 meters above the sea level (Ekiti Investors Handbook, 
2002). The landscape consists of ancient plains broken by 
steep-sided outcropping dome rocks. These rocks occur singly 
or in groups or ridges and the most notable of these are to be 
found in Efon-Alaaye, Ikere-Ekiti and Okemesi-Ekiti (EKSG, 
1997). The area is underlain by metamorphic rock of the 
basement complex. The State is dotted with hills of varying 
heights. The notable ones among them are Ikere-Ekiti Hills in 
the southern, Efon-Alaaye Hills in the western and Ado-Ekiti 
Hills in the central parts. 
The State enjoys the tropical climate with two distinct 
seasons. These are the rainy (April-October) and the dry 
(November-March) seasons with an annual rainfall of around 
1150mm. Temperatures range between 21° and 28°C with high 
humidity. The South-Westerly wind and the North-Easterly 
Trade winds blow in the rainy and dry (harmattan) season 
respectively. The tropical forest originally covered this part of 
Nigeria. However, as a result of exploitation for many centuries 
of exploitation, the original vegetation has been removed and 
now replaced with anthropic covers. Forest is now confined 
largely in the south, while savanna dominates the natural 
landscape in the north (Kayode, 1999 and EKSG, 1997). 
3. METHODOLOGY 
3.1 Data Acquisition and Image Preprocessing 
Relevant data were collected on the physical attributes of 
the five landuse types, i.e. farmland, built-up areas, forest 
regrowth, bare lands and water bodies, which were the 
dominant landuse in the area. Sample sites for data collection 
were determined from the remotely sensed imageries .For each 
landuse, five sample sites measuring 100 x 100m were selected 
and were fully described during field observations, variables 
examined for site characterization included dominant, concrete 
among others and drainage characteristics of the site . The 
coordinates of the sample sites were tracked with Global 
Positioning System (GPS) receiver. Secondary data used were 
Landsat TM, SPOT- XS NigeriaSat-1 covering the study area. 
Table 1 shows key parameters of the data used for the study. 
Images were obtained from the National Centre for Remote 
Sensing Jos, Forest Monitoring, Evaluation and Coordinating 
Unit (FORMECU) Abuja and Global Land Cover Facility 
(GLCF) an Earth Science Data Interface. The topographic map 
covering the study area was collected from the Ministry of Land 
and Surveys, Lagos. 
The satellite data were extracted one after the other as sub 
scenes from the original datasets. For the purpose of 
landuse/cover assessment, a common window covering the 
same geographical coordinates of the study area was extracted 
from the scene of the images obtained. This made the band Red, 
Blue, Green (RGB-123) colour combination. For SPOT XS 
data, Channel 3 was assigned red plane, Channel 2 to green and 
channel 1 to blue plane. The band combination then consisted 
of Blue, Green and Red (BGR-321) colour combination. For 
NigeriaSat_l data set, colour combination, channel 1 was 
assigned to red plane, channel 2 to green plane and 3 to blue 
plane. This puts the band combination as Red, Green and Blue 
(RGB-123). 
The geometric errors were corrected using ground control 
points (GCP). The process of georeferencing in this study 
started with the identification of features on the image data, 
which can be clearly recognized on the topographical map of 
the study area and whose geographical locations were clearly 
defined. Stream intersections and the intersection of the 
highways were used as ground control points (GCP). The 
latitude and longitude of the GCPs of clearly seen features 
obtained in the base map were used to register the coordinates 
of the image data used for the study. All the images were 
georeferenced to Universal Transverse Mercator projection of 
WGS84 coordinate system, zone 31N with Clarke 1866 
Spheroid. Nearest-neighbor re-sampling method was used to 
correct the data geometrically.