Department of Surveying and Geoinformatics

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    Open Access
    An Algorithm for Least Squares Computation Using the Manifold and Hilbert Space Dialectics
    (Theoretical Mathematics & Applications, International Scientific Press, 2012-03-12) OLALEYE, J.B.; ABIODUN, O.E.; OLUSINA, J.O.
    The method of least squares is widely used in numerical analysis of data in all applied quantitative fields. Although there is only one least squares criterion, several schemes have been used for its implementation. The manifold approach treats the entire least squares process, including the representation of the variables, the model formation and the computations, in terms of manifolds. A manifold is a group of variables or functions taken together and treated as an entity in the computation process. This paper presents the least squares optimization on the manifolds and shows that the express formation and solution of the usually formidable normal equations can be avoided by employing the Hilbert space axioms and methods in the Euclidean space generated by the axial manifolds. The sequential and systematic approach of the new scheme, the preservation of the group structure and the analytical insights it provides for understanding the fundamental geometry of the least squares problem, all of which are demonstrated in the sample applications presented, support the conclusions that the manifold approach is less daunting, requires less core storage space and facilitate better understanding of the problem and the solution.
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    Open Access
    Application of GIS Technology to Geospatial Location of Lagos State Fire Stations, Nigeria
    (Indian Journal of Geomatics, Indian Society of Geomatics, 2018-04-01) OMOGUNLOYE, O.G.; Otavboruo, B.E.; ABIODUN, O.E.; OLUNLADE, O.A.; Emesani, E.G.
    The number of lives and properties lost to fire outbreak has heightened the need for evaluating the efficiency of fire stations within Lagos State, Nigeria. In 2016, over 16 billion naira was lost to fire in the State. This research examined the application of GIS technology to geospatial location of Lagos State fire stations and their efficiencies. The aim of this research is to evaluate fire station distributions in relation to population and economic level within Lagos State using GIS technology. This evaluation provides various analyses to support efficient planning of fire services and identify areas that are less serviced within Lagos State. To accomplish this aim, graphical representation, Euclidean buffers, and network analyst, closest to facility mapping tool were used. The main data used were; Lagos State base map, XY coordinates of commercial/industrial buildings, thirty-four fire stations, (Federal, state and privately owned), and road network of Lagos State. The study revealed that within 1km coverage area, these thirty-four (34) fire stations owned by Lagos State (14 fire stations), Federal (8 fire stations) and Privately owned (18 fire stations) are insufficient for efficient service in the populated areas of Lagos state. The paper recommends need for more geospatially located fire stations in the populated areas of Lagos State for enhancing and achieving better and safe environments.
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    Open Access
    The application of remote sensing and GIS technology to erosion risk mapping
    (Multidisciplinary Digital Publishing Institute, 2018) Makinde, E. O.; Oyebanji, E. I.
    Erosion is one of the major problems in Nigeria and Lagos State in particular. The objectives of this research are to identify land use/land cover changes in Eti-Osa LGA and estimate actual erosion risk using Revised Universal Soil Loss Equation (RUSLE) model. In addition, this research evaluates the perception of communities within the study area with the view of understanding the risk involved in erosion. The result showed that the sediment yield of the study was estimated to be between 0 to 48 ton/ha/yr. The estimated soil losses were higher at Eti-Osa West, parts of Iru/Victoria Island, and Ikoyi/Obalende areas recorded low losses. Land uses mostly affected by very high and severe erosion are the bare soils and the crop lands having about 3% to 4% respectively compared to the others. It was concluded that combination of rainfall, lack of cover for the surface soil, were the major causes of soil loss in the study area.
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    Open Access
    An Assessment of the spectra characteristics of vegetation in south western Nigeria.
    (IERI Procedia, 2014) Omodanisi, E. O.; Salami, A. T.
    This study assessed the status of oil spill induced stress in the vegetation in Lagos and Ogun States, in the South West of Nigeria. The locations of oil spill impacted areas were identified on the field using information from the locals and a Global Positioning System with an accuracy of ± 5m and subsequently identified on the 5 m resolution RapidEye satellite image of 2009 and 2011. Field spectra were collected using Analytical Spectral Device (ASD) Handheld2 Spectrometer. The results showed varying spectral measurement of the impacted and the control. Indices were then used to distinguish less stressed from stressed vegetation which were statistically higher at F-ratio 4.825 (p < 0.01) and 3.194 (p < 0.01) in Lagos State; and 4.564 (p < 0.01) and 2.731 (p < 0.1) in Ogun State. It was concluded that oil spill had changed the spectra characteristics of impacted vegetation.
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    Open Access
    Automatic Registration of Simultaneously Overlapping Images
    (NED University Journal of Research, 2015) Olaleye, J. B.; Ajayi, O. G.; Omogunloye, O.G.; Odunmosun, J. O.; Okorocha, C.V
    The application of remote sensing has proved to be of tremendous importance over time in earth observation, monitoring and development. Images (the output of a remote sensing process) provide an overview of a particular place and afford the observer the opportunity to extract detailed information that will aid in making informed decisions. However, these images often come in overlapping patches from the sensor and also are of two-dimensional (2D) views. For a holistic perspective and to enable a stereoscopic view of the desired scene of interest, the bit by bit images must be fused together to produce a single image (mosaic). This fusion is the sole thrust of image registration. This study is intended to provide solution to the traditional (manually assisted) image registration by developing a model that performs automatic conjugate point identification, feature match and registration of multiple overlapping images. An approach which makes use of the relationship between the total matched points and final estimated inliers voted for the automatic registration is proposed for the evaluation of the model? accuracy.
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    Open Access
    Comparison between Landsat 7 Enhanced Thematic Mapper Plus (ETM+) and Landsat 8 Operational Land Imager (OLI) Assessment of Vegetation Indices.
    (Nigerian Journal of Environmental Sciences and Technology (NIJEST), 2017) Makinde, E. O.; Obigha, A. D.
    The Landsat system has contributed significantly to the understanding of the Earth observation for over forty years. Since May 2013, data from Landsat 8 has been available online for download, with substantial differences from its predecessors, having an extended number of spectral bands and narrower bandwidths. The objectives of this research were majorly to carry out a cross comparison analysis between vegetation indices derived from Landsat 7 Enhanced Thematic Mapper Plus (ETM+) and Landsat 8 Operational Land Imager (OLI) and also performed statistical analysis on the results derived from the vegetation indices. Also, this research carried out a change detection on four land cover classes present within the study area, as well as projected the land cover for year 2030. The methods applied in this research include, carrying out image classification on the Landsat imageries acquired between 1984 – 2016 to ascertain the changes in the land cover types, calculated the mean values of differenced vegetation indices derived from the four land covers between Landsat 7 ETM+ and Landsat 8 OLI. Statistical analysis involving regression and correlation analysis were also carried out on the vegetation indices derived between the two sensors, as well as scatter plot diagrams with linear regression equation and coefficients of determination (R2). The results showed no noticeable differences between Landsat 7 and Landsat 8 sensors, which demonstrates high similarities. This was observed because Global Environmental Monitoring Index (GEMI), Improved Modified Triangular Vegetation Index 2 (MTVI2), Normalized Burn Ratio (NBR), Normalized Difference Vegetation Index (NDVI), Modified Normalized Difference Water Index (MNDWI), Leaf Area Index (LAI) and Land Surface Water Index (LSWI) had smaller standard deviations. However, Renormalized Difference Vegetation Index (RDVI), Anthocyanin Reflectance Index 1 (ARI1) and Anthocyanin Reflectance Index 2 (ARI2) performed relatively poorly because their standard deviations were high. The correlation analysis of the vegetation indices that both sensors had a very high linear correlation coefficient with R2 greater than 0.99. It was concluded from this research that Landsat 7 ETM+ and Landsat 8 OLI can be used as complimentary data.
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    Open Access
    Creation of a Cell-Based Digital Cadastral Mapping System (Digital Cadastre): A Case Study of Goshen Beach Estate, Lekki Peninsula, Victoria Island.
    (2011-12) Olusina, J.O.; Olaleye, J.B.; Alademomi, A.S.; Ojie, T.I.
    The analogue ways of land administration over the years in developing countries have brought retrogression to land development and its sustainability as a limited natural resource. The use of pencil and papers in land management is outdated and has reduced efficiency. Fast delivery of land related products from government authorities and the private sector takes weeks or months. The need for transformation from analogue approach (traditional cadastre) into the digital technology era (digital cadastre) in order to derive the seemingly unlimited benefits is pertinent. Digital cadastre enhances land transaction activities to be conducted in a business manner. Similarly, land subdivision or boundary redefinition, land registration and land marketing are achieved with better accuracy. This paper discusses the need to introduce a national Cell-Based Digital Cadastral Mapping System model (DCMS) that spans from the federal level down to the states, local governments and the private enterprises such as estate surveying firms. That is, from geodetic accuracy to tertiary (micro) accuracy in order to achieve a seamless nationwide digital cadastre coverage. At the micro level of creating DCMS, Goshen Beach Estate in Lekki Peninsula was used as a case study. The use of Unique Parcel Identifier (UPI) and Spatial Indexing were discussed. Quasi-Land analysis was carried out. From this study, it was discovered that productivity and delivery of land information are enhanced; opportunity of multiple users guides against data and resources duplication; and legal, technical (organizational and technological) and financial issues are better tracked and tackled using DCMS.
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    Open Access
    Ecological effects and perceptions of victims of pipeline explosion in a developing country.
    (Springer International Journal of Environmental Science and Technology, 2015) Omodanisi, E. O.; Eludoyin, A. O.; Salami, A. T.
    Petroleum pipeline network is a critical infrastructure that should be protected because of its importance and the danger of fire disaster and ecosystem disruption if unprotected. However, the procedure for the management of the pipeline in Nigeria is probably faulty, and we think that this accounts for the multiple occurrences of pipeline fires in Nigeria between 1998 and 2007. Our study involves the use of satellite imageries, ecological sampling, questionnaire and personal interaction with some of the victims of the December 2006 pipeline fire in Ilado-Odo community in Lagos State, Nigeria. We attributed the causes of pipeline fires to poor pipeline network monitoring, poor communication and transportation in the vulnerable communities, and the inability of the pipeline management agency to ensure adequate community participation. We found that the biotic and abiotic components of the Ilado-Odo community were severely impaired, and we think that the impact may last for a long time if there is no post-disaster recovery programme. We conclude that the present method of labour-intensive approach to pipeline monitoring in Nigeria can promote further development of organised crime as explained by the Queer Ladder concept. We therefore recommend better tracking system, enhanced communication and transport infrastructure, as well as the review of the existing right-of-way regulations, and their strict enforcement around all critical infrastructures.
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    Open Access
    The effect of oil pipeline vandalization on the Mangrove Vegetation: A case study
    (Elsevier (Scopus) International Statistical Institute (ISI, Netherlands) Journal, 2011) Omodanisi, E. O.; Salami, A. T.; Oke, S. O.
    This study identified the area impacted by oil spill, explosion, and fire; and assessed the effect of the vandalization of oil pipeline on the vegetation in Ilado area of Lagos State of Nigeria. The study reveals that Rhizophora mangle (38.5 %) and Cocos nucifera (22.2 %) were the dominant woody plant species in the area while Rhizophora mangle (23.0 %) and Phoenix spp (26.6 %) were dominant in the control quadrat. The girth size-class distribution of woody plants species did not conform to the inverted J-curve structure characteristic of stable vegetation. Oryza longistaminata was the most abundant species with 38.5 % in the nine affected quadrats and Pennisetum purpureum with 32.8 % in the control. Species diversity index revealed that the control quadrat had a species diversity of 0.68 while that of the nine affected quadrats had the species diversity of 0.37. It was concluded that oil spill from vandalization and the resultant fire resulted in the reduction of mangrove vegetation and changes in its species composition and distribution.
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    Open Access
    Establishment of an empirical geoid model for a small geographic area: A case study of Port Harcourt, Nigeria.
    (Surveying and Land Information Science, 2010) Olaleye, J. B.; Aleem, K. F.; Olusina, J. O.; Abiodun, O. E.
    This paper examines changes in land-use and land-cover pattern in Ilorin Emirate in Nigeria between 1986 and 2006. Landsat images of Ilorin Emirates at three epochs (1986, 2000 and 2006) were used. An administrative map of local governments in Kwara State and a land-use map of Ilorin were used as base maps. Global Mapper Software was used for the image enhancement; image classification was done with environment for visualizing images (ENVI) software and was later exported to the ArcGIS for further processing and analysis. The land consumption rate and land absorption coefficient was determined to aid the quantitative assessment of change. Subsequently, an attempt was made at projecting the observed land-use / land-cover for a period of 14 years ending at 2020. The result of the work shows a gradual growth in built-up land between 1986 and 2000 and this tends to grow more rapidly between 2000 and 2006. It was also observed that the change by 2020 may likely follow the trend observed in 2000 and 2006. It is recommended that the information from the results of this work should be use to optimally and effectively plan and manage the study area.
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    Open Access
    Evolving a Comprehensive Geomatics Multi-Criteria Evaluation Index Model for Optimal Pipeline Route Selection
    (Taylor & Francis Online, 2020-02-17) Hamid-Mosaku, I.A; Oguntade, F.O; Ifeanyi, V.I; Balogun, A; Jimoh, A.O
    Selection of pipeline routes is a geospatial multi-criteria evaluation problem since it involves the assessment of technical, environmental and safety-related factors that influence pipeline system operations. This study determines the optimal pipeline route for transmission of oil and gas products using the Dangote Refinery Project in Nigeria as a case study. Pertinent route selection factors were identified and structured into the expert feedback model of the Analytical Network Process (ANP) for accurate prioritization. LANDSAT 8 imageries of the study area were processed and classified into various land use and land cover types, which were further modelled in ArcMap 10.2 GIS software for routing analysis. Findings reveal that the most highly prioritized factors for proper route selection were the environmental and geological factors, while the least prioritized was the economic factor. In the end, alternative Route 2 was identified as the optimal route among the four evaluated alternative routes because of its minimum route length, minimum passage length through sensitive settlement areas, and less number of river, stream and existing platforms’ crossings.
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    Open Access
    Facility Mapping of University of Lagos
    (Journal of Geoscience and Environment Protection, 2017) Makinde, E. O.; Adebangbe, S. A.; Erinjogunola, B. A.
    This paper shows a detailed methodology for creating 2D and 3D visual facility map of the campus. The purpose of this study work is to develop an interactive interface containing the 2 and 3-Dimensional features of all the facilities within the University of Lagos. The spatial attributes of the facilities were collected with the aid of total stations. The most recent Google earth software was used as source of data to produce 2-dimensional facilities of the study area through digitization process. SRTM Digital elevation model image was downloaded from United State Geological Survey website to give the elevation data required for the 3-dimensional representation. All these data were processed with ArcGIS 10.2.1.
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    Open Access
    Fuzzy MCDM-based GIS model for subsea oil pipeline route optimization: An integrated approach
    (Taylor and Francis, 2017) Balogun, A-L.; Matori, A-N.; Hamid-Mosaku, I.A.; Umar Lawal, D.; Ahmed Chandio, I.
    Proper pipeline route selection is an integral component of a typical oil exploration and transportation project. Improperly selected routes could have severe consequences including pipe failures, oil spillage, and environmental disasters. Consequently, technologies like geographic information systems (GIS) are increasingly being used to facilitate the oil pipeline route selection procedure—especially for onshore routing projects. Surprisingly, not much has been documented on the application of GIS to offshore pipeline routing. With recent discoveries on the merits of offshore oil exploration, it is necessary to extend the analytical capabilities of GIS to the unique offshore domain. However, concerns have been raised regarding the limitations of GIS in accurately prioritizing diverse selection criteria in typical multi-criteria decision-making (MCDM) problems like route selection. Consequently, this paper addresses the offshore/subsea pipeline routing constraint using a hybrid decision support system (DSS), which integrates a GIS and fuzzy logic-based approximate reasoning (AR) models for optimal performance. The resultant spatial decision support system (SDSS) was successfully applied to a case study in Malaysia. The AR algorithm calculated the significance level of the multiple criteria using various fuzzy linguistic variables and membership functions. The aggregated priority ranking from different pipeline routing experts showed that the overall influence of the environmental criteria (61.4%) significantly exceeded that of other equally important criteria in the study area. These rankings were inputted into the SDSS to simulate various probable routes. Final results accurately highlighted an optimal route, which places a premium on the protection of environmental features in the subsea study area—in alignment with the preferences of majority of the experts.
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    Open Access
    Geodesy and environmental management: – a case for the adoption of geomatics engineering
    (Nigerian Journal of Geodesy, Nigeria Association of Geodesy, 2018-11) OLALEYE, J.B.; ABIODUN, O.E.; BABALOLA, A.
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    Open Access
    Geoidal Map and Three Dimension Surface Model
    (International Journal of Computational Engineering Research (IJCER), Vol. 2. No. 4, pp 52-58., 2013) Olaleye, J. B.; Olusina, J.O; Badejo, O.T; Aleem, K.F
    Geoidal map depicts the geoid configuration of the area under study. Data acquisition for the production of such maps has been very tedious, time consuming and expensive with the use of classical and conventional geoid determination methods. "Satlevel" Collocation is a new method of geoid determination in which the ellipsoidal height from any satellite based system is combined with orthometric height from geodetic levelling to model the geoid. The method enables the geoid to be determined in patches. Geoid so determined can be applied with ellipsoidal height to get orthometric height which height users always prefer. In this work, "Satlevel" Collocation model along with the user‟s interactive computer program “Orthometric Height on Fly”, were used to generate geoidal values in part of Port Harcourt metropolis. The generated data was used to produce the Geoidal map of the study area using SURFER software. The map was overlaid on the Local government map of Rivers State of Nigeria. The production of Geoidal map from "Satlevel" Collocation is easier than the conventional methods, when the initial geoidal coefficients have been determined. This method can be extended to other parts of Nigeria and the world at large.
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    Open Access
    Geoinformatic assessment of urban heat island and land use/cover processes: a case study from Akure
    (Springer Environmental Earth Sciences, 2019) Makinde, E. O.; Agbor, C. F.
    Akure is one of the cities undergoing rapid growth in Nigeria, which has resulted to remarkable Urban Heat Island (UHI) effect. To examine the impact of this development in the city and its environs, this study derived the brightness temperatures and land use land cover (LULC) types using Landsat images between 1984 and 2016, of 190/55 path and row. Normalized Difference Built up Index (NDBI) and Normalized Difference Vegetation Index (NDVI), were used as LULC indicators for sub-pixel analysis. The results of this study revealed a remarkable change in built-up area at the expense of vegetation (forest) and bare lands. The sub-pixels analysis between land use/cover indicators and temperature revealed a strong correlation between LULC and temperature in the area. Findings revealed a 4.63 °C temperature increase in vegetated areas between 1984 and 2016; and an overall temperature values ranged from about 14 to 36 °C, which have been categorized into six classes (< 20 °C, 20 °C to < 24 °C, 24 °C to < 28 °C, 28 °C to < 32 °C, and ≥ 32 °C). The temperature increase over the years and the strong correlation between temperature and land use land cover suggests, that any small undesirable change in land use land cover in the future would lead to severe environmental condition.
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    Open Access
    Geospatial Assessment of Carbon Sequestration in Oluwa Forest, South-West Nigeria
    (Nigeria Journal of Environmental Sciences and Technology (NIJEST), 2017) Makinde, E. O.; Ogundeko, M. O.; Womiloju, A. A.
    The potential of the forest as a natural sink is vast and enormous and has been well documented in several types of research and reports. This project is an attempt at re-emphasizing this potential, by using geospatial technology, to quantify the amount of carbon sequestered by the Oluwa Forest Reserve. Remote sensing methods, specifically supervised image classification augmented with field data, were employed. Landsat imageries of 1984, 1991, 2002, 2010 and 2015 were obtained and the maximum likelihood supervised classification algorithm was used in obtaining the landuse/land cover information for those years. From this, the trend in the landuse was monitored and ascertained. The study revealed two distinct tree species, and subsequently, four forest strata were established. The heights and diameters at breast height of the trees from ten randomly selected 20 m × 20 m sample points, were measured. The allometric equation of Brown (1989, 1997) was used in estimating the above ground and belowground biomass while the Soil Organic Carbon (SOC) was obtained from the laboratory test on the soil samples, taken at 0 –15 cm, and 15 – 30 cm from the ten sample points using the Walkey Black method. The total above and belowground biomass was obtained to be 162,826.343 Mg/ha and 32,565.269 Mg/ha respectively while the total SOC was 5.7971 Mg/ha. The total carbon sequestered by the forest was estimated to be 358.565 Mg Ca. A multiple regression analysis was carried out and an adjusted r-squared value of 0.9809 with an f-test significance of -0.000000401 was obtained. This is to find the correlation between the biomass and the dbh, diameter at breast height and the tree heights, h.
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    Open Access
    Geospatial Assessment of the Impact of Urban Sprawl in Akure, Southwestern Nigeria.
    (Journal of Geoscience and Environment Protection, 2018) Usman, V. A; Makinde, E. O.; Salami, A. T.
    This study analyzed trend and examined the factors responsible for urban sprawl in Akure with a view to develop a user-friendly geospatial database for monitoring urban sprawl in the study area. Medium resolution satellite imageries derived from Landsat (TM) and (ETM+) comprising of four dates (1986, 1991, 2002 and 2011) were analyzed. The results revealed that built-up area increased rapidly by 43.31% from 5857.54 hectares in 1986 to 8394.21 hectares in 1991. It further increased by 72.02% from 8762.76 hectares to 15073.7 hectares in 2011. Field study conducted in 2013 involved in-depth interviews and questionnaires to stakeholders and residence respectively. The analysis showed that there was a weak negative relationship (r = −0.189, p < 0.01) between gender and “house ownership”, a weak positive relationship (r = 0.343, p < 0.01) between marital status and “house ownership” and a weak negative relationship (r = −0.159, p < 0.05) between “number of children” and “house ownership” in the sprawl location. Geo-spatial database modeled was tested by subjecting it to spatial analysis to show its capability to answer question pertaining to all the entities of the database. The study concluded that urban sprawl increased and if not reversed, might constitute greater social and environmental problems in the future.
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    Restricted
    The geospatial modelling of carbon sequestration in Oluwa Forest, Ondo State, Nigeria
    (Taylor and Francis European Journal of Remote Sensing, 2017) Makinde, E.O.; Womiloju, A.A.; Ogundeko, M.O.
    The study assessed the amount of carbon being sequestrated in the Ondo State Afforestation Project in Oluwa Forest, south -west of Nigeria, with the view to determine the above ground biomass (AGB) and belowground biomass (BGB), estimate the total carbon content and evaluate the CO2 sequestered. Geospatial techniques and the non-destructive field observation method were used. The results showed that a total of 359 megatons of CO2 was estimated to have been sequestered using the non-destructive field measurements. In addition, the rate of change in land use land cover between 1984 and 2015 was determined. A geospatial database derived from field measurements was developed to monitor carbon content of the forest.
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    Open Access
    The geospatial modelling of carbon sequestration in Oluwa Forest, Ondo State, Nigeria.
    (European Journal of Remote Sensing, 2017) Makinde, E. O.; Womiloju, A. A.; Ogundeko, M. O.
    The study assessed the amount of carbon being sequestrated in the Ondo State Afforestation Project in Oluwa Forest, south -west of Nigeria, with the view to determine the above ground biomass (AGB) and belowground biomass (BGB), estimate the total carbon content and evaluate the CO2 sequestered. Geospatial techniques and the non-destructive field observation method were used. The results showed that a total of 359 megatons of CO2 was estimated to have been sequestered using the non-destructive field measurements. In addition, the rate of change in land use land cover between 1984 and 2015 was determined. A geospatial database derived from field measurements was developed to monitor carbon content of the forest.