Browsing by Author "Onunkwo, A. A."

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    Application of geographic information system (GIS) in accuracy assessment of existing land use map a case study of Enugu Area, South-Eastern Nigeria
    (Scientific & Academic Publishing, 2012) Onunkwo, A. A.; Nwankwo, G. I.; Uzoije, A. P.; Okereke, C. N.
    It is suspected that continuous building collapses within Enugu area is due to faulty landuse map. This work aims at employing geographic information system principles to assess the validity of the existing landuse map of Enugu area. Three landuse options were considered (Industrial, residential and waste). The study was undertaken using Arc view 3.2a academic, Excel Statistical Software and autocard software of GIS. A total of 12 landuse determinants were selected as thematic data layers and basic factors influencing the choice of industrial, residential and waste disposal landuses. Soil characteristics and geology were integrated into the thematic maps to facilitate the weighting of the basic determinants. The thematic layers were weighted on a scale of 0% - 100% and 0-2 inclusive, using the criteria obtained from field work and laboratory investigation. The thematic layers for each landuse were subjected to overlay using arc view software overlay model builder. The operation yielded three (3) different landuse maps (Industrial, residential and wasted disposal,) which were further superimposed to produce a composite landuse map useful for regional and urban planning. Correlation with existing landuse map, exposed a lot of limitations of the existing landuse map. All the residential and industrial areas of the existing landuse map fall within the low capacity areas of the present study. Areas selected as open space by the existing landuse map correspond to the areas of industrial and residential land uses of the present study. Areas limited for use by the present study due to hazards of flooding, landslide, fault and gully erosion were not considered by the existing landuse map, rather they were mapped out for industrial, residential and partly as open space. The existing landuse map has no provision for waste disposal. The present study shows that areas to the West, Southwest and Southeast are highly suitable for industrial and residential landuses. The limitations of the existing landuse map exposed by the present study must have accounted for the cases of building collapses in the area.
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    Application of geographic information system (GIS) in industrial land capability index mapping of a developing country . a case study of Enugu area , South- Eastern Nigeria
    (2011-08-05) Onunkwo, A. A.; Uzoije, A. P.; Onyekuru, S. O.
    It was projected that the population of Enugu area will grow at approximately 300% by the year 2020. The information is further strengthened by the projected 3,237,298 population figure of the area. This implies that there is the expectation of overpopulation of the area in future. Unemployment and lowering of people’s standard of living are always associated with over population. It therefore, becomes necessary to map out areas on a sustainable basis and most suitable for the sighting of industries to employ the teeming population. Land capability index mapping using Geographic Information System (GIS) principles was used for this study. The study was undertaken using Arc View 3.2a academic, Excel statistical soft-ware and auto card software of GIS. A total of 12 land use determinants were selected as thematic data layers and basic factors influencing the choice of industrial land use. Soil characteristics and geology were integrated into the thematic maps to facilitate the weighting of the basic determinants. The thematic layers were weighted on a scale of 0%-100% and 0-2 inclusive, using the criteria obtained from field work and laboratory investigation. The thematic layers were subjected to overlay using arc view soft ware overlay model builder. The operation yielded a layer of preferred industrial land use options in a map form. 3 areas of varying suitabilities (Area 7,8 and 9) resulted from this operation. Area 7 occupies 10% of the study area suitable for industrial land use options; area 8 occupies 70% and has low suitability for industrial land use while area 9 occupies 20% of the land unit unsuitable for industrial land use.
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    Engineering properties and uses of soil derive from maastritchian Ajali formation in a part of Se Nigeria
    (European Centre for Research Training and Development UK (www.eajournals.org), 2014-12) Onunkwo, A. A.; Uzoije, A. P.; Onyekuru, S. O.
    The study is necessitated by the recent move by Imo State government of Nigeria to raise Okigwe town to urban status. Ajali Formation being the prominent geological terrain in Okigwe area, most structures would be erected on the soil derived from it. The parameter measured include grain size, atterberg limits, and compaction, shear strength, permeability and porosity as well as bulk density. The result shows that the soil underlain by Ajali Formation within Okigwe area is sandy silt with low clay content and has plasticity index, bulk density, porosity and permeability values of 9.65%, 2.06%,kg/m3, 0.45 and 0.35cm/s respectively. The value for the optimum moisture content (OMC) maximum dry density(MDD) shear strength, angle of internal friction are 13.5%, 2.06kg/m3, 106.86KN/M2 and 28.4o. These values indicate that the soil derived from Maastrichtian Ajali Formation within Okigwe area of south eastern Nigeria is of high strength, porous and permeable and can be used as a recharge site for regional aquifer, but cannot be used as a waste disposal area or for road construction. The soil due to its low plasticity index with no swelling characteristics and high shear strength is a good site for building foundations, but cannot be used in dam construction. It is ideal for projects requiring good drainage and embankments. However, for the soil to be used in any engineering construction works, it has to be compacted to its maximum dry density value of 2.06kg/m3 within the range of optimum moisture content of 13.5% as to achieve maximum strength.
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    Ground water quality assessment of newly created Local Governments in Nigeria – A case of Nkwerre, Local Government, Imo State
    (U. P., 2013) Onunkwo, A. A.; Uzoije, A. P.; Onyekuru, S. O.; Agumanu, A. E.; Chinaemelu, E. S.
    The creation of new Local governments in Nigeria brought about new socio-economic order such as over population, pressure on the available facilities and new land use elements with their generated wastes. There is the need to examine the present status of the underground water resource of these regions for effective development of the newly created local governments. For this reason it becomes necessary to carry out the ground water quality assessment of newly created local governments in Nigeria as a source of data base for development using Nkwerre Local Government Area of Imo State as a case study. The study was carried out by acquiring geologic and topographic maps of the area for easy identification of sample population areas and to identify geological boundaries, Spring out crops, landuse element especially waste dump sites. Agricultural and industrial projects were visited and examined. A total of 6 water samples from bore holes within six communities were collected and analyzed. Analysis was carried out using atomic absorption spectroscopy for major cations. Heavy metal analysis was undertaken using spectrophometer, potassium was determined using flame photometer method, concentration of total iron (Fe2+) was determined calorimetrically using spekker absorption meter while total dissolved solids (TDS) was determined using glass fiber filter. Turbidity. Physical parameters like ph and dissolved oxygen were measured insitu in the field with appropriate standard maters. The result of geochemical analysis shows that the water has high turbidity, high iron, slightly acidic, soft portable and suitable for industrial, agricultural and domestic purposes, but requires treatment to reduce iron and turbidity. The water type belongs to a no dominant cation and anion type and can be grouped as Mg2+-Ca2+ - So42+ - HCo3 water. North western segment in infested with ecoli bacteria. The general pollution index of 0.777 shows that the water in the area is ideal for various purposes, however, remediation of iron, turbidity and bacteria presence is proposed.
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    Resistivity methods of aquifer mapping and pollution vulnerability assessment of a part of Imo River Basin of South-Eastern Nigeria (A case study of Mbaitoli Local Government Area of Imo State, Nigeria)
    (IDOSI Publications, 2011) Onunkwo, A. A.; Uzoije, A. P.; Essien, A. G.
    Aquifer mapping and pollution vulnerability assessment of a part of Imo River basin of South-eastern Nigeria has been carried out with the aim of addressing the underground water exploitation problems inherent in the area. The instruments used for the study include aerial photographs, satellite images, topographic and geologic map of the area. Geophysical investigations were carried out with the aid of terrameter 300 SAS employing vertical resistivity soundings. Eleven selected locations were sounded using Schulumberger array with maximum electrode separation of 900 meters. Result shows that the area has average lithology of eight (8) layers with underground water occurring between the fourth and fifth layers. The lithology is dominantly sand (about 90%) sandstone (about 2%) clay / shale (about 8%). Average depth to top of aquifer ranges from 100 to 228 meters. Depth to the base of aquifer ranges from 88m to 278m while the average aquifer thickness is 33.7m. Three aquifer systems exist in the area-confined, unconfined and semi-confined. Semi-confined aquifer is dominant, while unconfined aquifer is less common. The former offers natural protection against pollution of underground water by waste effluents while the later is prone to pollution. Average resistivity of the formations is relatively high indicating a formation likely to contain abundant conglomeritic and sandstone beds capable of promoting loss of circulation and difficulty in drilling bit penetration during underground water exploitation. Areas to the west are relatively shallow while the South (Egbeada) is very deep. There is an insignificant relationship between aquifer depth and elevation. This section of Imo River basin is promising for underground water development but requires caution since conglomeritic and sandstone traces can effect adversely underground water exploitation. Down the hole electric logging is necessary considering the aquifer depth. The problem of unprotected aquifer against environmental pollution should be noted and addressed.