INTEGRATION OF GIS, GPS, GSM AND REMOTE SENSING, (3GR) FOR ROAD ACCIDENT REPORTING AND MANAGEMENT

Abeokuta metropolis is gradually developing into a mega city in Nigeria. At the moment the municipality spans 4 local government areas and the sprawl has just started. Along with the city expansion is the increase of vehicular movements and concomitant vehicular accidents. There is therefore a need for development of an accident, reporting data collection, referencing, management and analysis system, for Abeokuta city. Consequently, the paper looks at a GIS based integration of spatial technologies for near real time reporting and management of road traffic accident in the city. In the study, an accident database management system was developed  to store urban traffic accident data, and analyze these data in terms of their attribute and spatial characteristics in order to exploit the reasons for accidents, the hot spots and rank the urban area with various degrees of danger. Foremost, the study established a road network in ArcGIS for Abeokuta metropolis. Next, locations of fatal and minor road traffic accidents data within the metropolis in the last five years were geo-referenced with the aid of GPS and the attributes were developed into a database. Reasons for road accidents were analysed in order to summarize major factors related to the accidents. Finally a hazard map was created to show the accident hot spots and degree of danger with respect to road accident in the city. The paper particularly explains the method of using Mobile phones to report accidents by eye witnesses while using the GPS to reference the accident locations. The incorporation of GIS map along with some monitoring systems like the Personal Digital Assistants (PDAs) was identified as pedestal for the development of  real-time or near-real time accident reporting and management system.Â

AN ASSESSMENT OF URBAN ENCROACHMENT ON OGUN RIVER BANK PROTECTION ZONE IN ABEOKUTA CITY, NIGERIA

An assessment of urban sprawl in Abeokuta city, Nigeria from 1964 to 2008 was conducted. The study investigated the rate of encroachment of buildings on the Ogun River bank using Geographical Information Systems and remote sensing techniques. Topographic map of the city was scanned, imported into GIS, and digitized. Series of multi-date remote sensing satellite imageries were also acquired, processed, classified (where necessary) and vectorized to enable full assessment of the spread of built up area into the River bank Protection zone (RBPZ). A recent, high resolution satellite (Ikonos) image was utilized to assess the situation at present.  Results of the assessment revealed progressive spatial expansion in the city and progressive encroachment on Ogun river right of way. Particularly, gross encroachments were pronounced in the aboriginal part of the city. A total of 34.1ha of built up area are completely within the protection zone as at 1964, this increased to 50ha in 1974, 77 ha in 1984 and 90 ha in 1994. In the year 2008, the encroachment was almost four times (123 ha) what it was in 1964. The study demonstrated that use of remote sensing and GIS is very useful and effective for the monitoring of urban sprawl. It provides a tool of the quantitative measurement that is needed for rapidly growing regions in identifying internal variations and temporal change of urban sprawl patterns in different periods. Â

HUMAN HEALTH AND ENVIRONMENTAL RISK ASSESSMENT OF THE ALAKIA INDUSTRIAL DISTRICT OF IBADAN, SOUTH WEST NIGERIA

A scientific survey was conducted in February 2002 in three communities (Majawe, Osun-Abolowojaiye and Papa Adogba) communities of Alakia Industrial district of Ibadan to determine the extent of the damages caused by the negative impact of the industrial effluent discharges into the Elesin stream and emissions of gaseous pollutants into the atmosphere within the three communities. A socio-economic survey was also carried out to establish the impact(s) on human and livestock populations of the study area. A sample of non-affected areas served as control for comparison. The degree of pollution was established by the determination of the concentrations of the metals including Pb, Ca, N, K, Cd, Fe, Zn, Ca, Cr, Mn, Na, Mg, a specific non metal phosphorus as well as chlorides (Cl-) and Nitrates (N03-). The study established the presence of metals in concentrations higher than the recommended limits in effluent discharges in all the samples in the study area and a clear link between the effluent discharges and pollution with its severe damages in the area

QUALITATIVE AND QUANTITATIVE ASSESSMENT OF RAINWATER HARVESTING FROM ROOFTOP CATCHMENTS: CASE STUDY OF OKE-LANTORO COMMUNITY IN ABEOKUTA, SOUTHWEST NIGERIA

Quantitative and qualitative assessment of Rainwater harvesting system from rooftop runoff from acatchment at Oke-Lantoro Community in Abeokuta, Southwest Nigeria was determined using eightroof designs in respect to slope and six selected roofing sheet materials respectively. The resultshowed that the steeper the roof slope the more the rainwater harvested irrespective of rainfall amountand duration. The roof pattern with a large and steep slope designed with gutter tends to harvest morewater and at a higher rate. Physico-chemical analysis of the harvested water samples gave resultswhich varied from various drinking water quality regulatory standards. Sample from galvanized roofingsheet was influenced by zinc and lead in quantity beyond human consumption level, while the asbestosroofing sheet water sample gave higher calcium and magnesium contents which reflected in thetotal hardness value. Sample from the aluminum roofing sheet gave the best result but it was alsoaffected by the influence of atmospheric dust particles and faecal materials of birds, lizards and othersmall organisms. Considering the results of the physico-chemical tests, the harvested water samplescould be put to other domestic uses, as they cannot be consumed directly

COMPARATIVE ASSESSMENT OF CARBON STORAGE IN BIOMASS AND SOIL ORGANIC CARBON IN TEAK PLANTATION OF DIFFERENT AGES IN YEWA NORTH, OGUN STATE, NIGERIA

Tree act as a sink for CO2 by fixing carbon during photosynthesis and is a vital tool to alleviate climate change through CO2 absorption from the atmosphere. This study was conducted to assess carbon storage in tree biomass and soil carbon stock in Teak (Tectona grandis) plantations of different age series (5, 9 and 12 years). Data were collected on diameter at breast height (Dbh) and total height (TH) of all the trees in a sample plot of 1000 m2 in each plantation of age series. Carbon stored was evaluated based on tree growth variables, soil parameters and above ground biomass. Topsoil and subsoil (0-15 and 15-30 cm) samples collected from three sites were analyzed for organic carbon (OC) following standard methods.  Mean diameter at breast height were 67.11, 45.42, and 21.35 cm ha-1 and the mean volumes were 0.39, 0.16 and 0.02 m3ha-1 for 12, 9 and 5 years old were significant different (p<0.05). The highest value of total soil organic carbon (TSOC) was 8464.65 t.ha-1 for the 12year-old followed by 4430.25 t.ha-1 for 9 years old stand and 3004.95 t.ha-1 for 5years old were significant different (p<0.05) respectively. The total soil organic carbon per hectare were higher for the older than the younger Tectona grandis stand (8464.65 t.ha-1, 4430.25 t.ha-1 and 3004.95 t.ha-1) were significant different (p<0.05). Total carbon storage by soil and in biomass (CSB) was 15899.85 and 49.31 tons.ha-1 and total carbon accumulated by the plantation under investigation was in the order of 12 years old > 9 years old > 5 years old, respectively. The results of this study confirm that teak has good potentials to offer carbon sequestration through its soil and accumulate large amount of biomass carbon. The plantation ownership should be guided properly on the management activities such as thinning, pruning and weeding operation as well as indiscriminate removal of individual caused by anthropogenic activities should be avoided.     &nbsp

Geographical information system and predictive risk maps of urinary schistosomiasis in Ogun State, Nigeria

<p>Abstract</p> <p>Background</p> <p>The control of urinary schistosomiasis in Ogun State, Nigeria remains inert due to lack of reliable data on the geographical distribution of the disease and the population at risk. To help in developing a control programme, delineating areas of risk, geographical information system and remotely sensed environmental images were used to developed predictive risk maps of the probability of occurrence of the disease and quantify the risk for infection in Ogun State, Nigeria.</p> <p>Methods</p> <p>Infection data used were derived from carefully validated morbidity questionnaires among primary school children in 2001–2002, in which school children were asked among other questions if they have experienced "blood in urine" or urinary schistosomiasis. The infection data from 1,092 schools together with remotely sensed environmental data such as rainfall, vegetation, temperature, soil-types, altitude and land cover were analysis using binary logistic regression models to identify environmental features that influence the spatial distribution of the disease. The final regression equations were then used in Arc View 3.2a GIS software to generate predictive risk maps of the distribution of the disease and population at risk in the state.</p> <p>Results</p> <p>Logistic regression analysis shows that the only significant environmental variable in predicting the presence and absence of urinary schistosomiasis in any area of the State was Land Surface Temperature (LST) (B = 0.308, p = 0.013). While LST (B = -0.478, p = 0.035), rainfall (B = -0.006, p = 0.0005), ferric luvisols (B = 0.539, p = 0.274), dystric nitosols (B = 0.133, p = 0.769) and pellic vertisols (B = 1.386, p = 0.008) soils types were the final variables in the model for predicting the probability of an area having an infection prevalence equivalent to or more than 50%. The two predictive risk maps suggest that urinary schistosomiasis is widely distributed and occurring in all the Local Government Areas (LGAs) in State. The high-risk areas (≥ 50% prevalence) however, are confined to scatter foci in the north western part of the State. The model also estimated that 98.99% of schools aged children (5–14 years) are living in areas suitable for urinary schistosomiasis transmission and are at risk of infection.</p> <p>Conclusion</p> <p>The risk maps developed will hopefully be useful to the state health officials, by providing them with detailed distribution of urinary schistosomiasis, help to delineate areas for intervention, assesses population at risk thereby helping in optimizing scarce resources.</p

Regional assessment of trends in vegetation change dynamics using principal component analysis

Vegetation forms the basis for the existence of animal and human. Due to changes in climate and human perturbation, most of the natural vegetation of the world has undergone some form of transformation both in composition and structure. Increased anthropogenic activities over the last decades had pose serious threat on the natural vegetation in Nigeria, many vegetated areas are either transformed to other land use such as deforestation for agricultural purpose or completely lost due to indiscriminate removal of trees for charcoal, fuelwood and timber production. This study therefore aims at examining the rate of change in vegetation cover, the degree of change and the application of Principal Component Analysis (PCA) in the dry sub-humid region of Nigeria using Normalized Difference Vegetation Index (NDVI) data spanning from 1983-2011. The method used for the analysis is the T-mode orientation approach also known as standardized PCA, while trends are examined using ordinary least square, median trend (Theil-Sen) and monotonic trend. The result of the trend analysis shows both positive and negative trend in vegetation change dynamics over the 29 years period examined. Five components were used for the Principal Component Analysis. The results of the first component explains about 98 % of the total variance of the vegetation (NDVI) while components 2-5 have lower variance percentage (< 1%). Two ancillary land use land cover data of 2000 and 2009 from European Space Agency (ESA) were used to further explain changes observed in the Normalized Difference Vegetation Index. The result of the land use data shows changes in land use pattern which can be attributed to anthropogenic activities such as cutting of trees for charcoal production, fuelwood and agricultural practices. The result of this study shows the ability of remote sensing data for monitoring vegetation change in the dry-sub humid region of Nigeria