Nigerian Journal of Environmental Sciences and Technology - October 2019
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189
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Published By University Of Benin - Faculty Of Environmental Sciences

2616-0501, 2616-051x
Updated Saturday, 13 November 2021

Author(s):  
Y.A. Maleeks ◽  
A.O. Aliyu ◽  
A. Bala ◽  
A.U. Isiaka ◽  
K.Z. Atta

The pattern of development in a city is mostly governed by urban dynamics, with population increase being the primary driving force. Built-up cover is the most important predictor of urban expansion. Zuru metropolis in Kebbi State has witnessed remarkable developmental activities caused by human influences such as buildings, road constructions, and population growth for over decades. Urban growth was ascertained for a period of 30 years through the analysis of Landsat imagery of 1988, 1998, 2008 and 2018. The datasets were classified into five (5) land covers, namely, built-up, water body, rocky surface, vegetation, and others. Quantitative assessment of the urban growth was ascertained by computing post-classification LC dynamics and Land Consumption Rate/Land Absorption Coefficient (LCR/LAC). The results showed that the built-up cover (urban area) conspicuously increased with area of 693.35 ha, 728.74 ha, 5210.5 ha and 6845.75 ha respectively for the period of study (1988 – 2018). The increment in built-up area was indicative of population growth from 1988 to 2018. The study revealed that between 1988 to 2018 showed that built-up increased by 11.78%, while rocky surface and water body have shrunk by 16.44% and 0.02% respectively, which can be attributed to anthropogenic activities in which rocky surface and waterbody have been transformed into built-up cover. It further revealed that the urban area experienced crowdedness in the years 2008 and 2018 respectively due to high LCR values of 2.71% compared to LCR values of 0.0714% and 0.0558% in 1988 and 1998. Land transformation into urban area and spread of the population to the outskirts of the study area was prominent between 1998 and 2008 due to high LAC value of 0.0998. The study concluded that there was transformation of rocky surface and waterbody into urban area, which was caused by population growth, human and agricultural activities in Zuru metropolis.


Author(s):  
G.O. Omoregie ◽  
B. Ikhajiagbe

The present study investigated the accumulation of selected HMs by Chromolaena odorata and the concomitant effects on leaf anatomical features. Top soils were collected from a marked plot and pooled together to obtain a composite sample. The soil was sun-dried to constant weight and measured into experimental pots at 20kg each). The pots were divided into 5 metal groups with 3 sub-groups each. Each group was polluted with Manganese (Mn), Cadmium (Cd), Copper (Cu), Lead (Pb) and Zinc (Zn) in their respective chloride forms. Concentrations of the metals in the soil were initially based on their respective ecological screening value/benchmark (ESV). The ESV values for the 5 HMs were 50, 4, 100, 50 and 50 mg/kg respectively. Within each group, the respective HMs was applied in 3 concentrations of 1ESV, 3ESV and 5ESV. The control experiment consisted of plants grown in soils with no exogenous application of the test metals. The experiment was triplicated. Twenty hours later, equal sized stem cuttings of C. odorata (2.0 – 2.3cm in thickness, 30 cm in length) were planted per experimental pot. Six months later, results showed significant accumulation of metals in plant stem, leaves, and most especially the root. Mn was the most accumulated HM in all plant parts (9.22 – 17.86 mg/kg), compared to Cd (0.85 – 1.66 mg/kg).Significant changes in folial anatomy were reported in HM-impacted plants compared to the control. There were more upper epidermal stomata (270 – 353 mm2) in Mn-exposed plants compared to the others. Increase in vascular bundle thickness (p<0.01) was reported in HM-exposed plants compared to control. Highly significant decrease in stem parenchyma thickness (p<0.01) never the less parenchyma thickness of HM-exposed plants ranged from 46.37 – 49.53 µm in Zn and Pb-exposed plants compared to 79.23 µm in the control.


Author(s):  
U.S. Ibrahim ◽  
T.T. Youngu ◽  
B. Swafiyudeen ◽  
A.Z. Abubakar ◽  
A.K. Zainabu ◽  
...  

The increased flood incidences experienced all over the world due to climate change dynamics call for a concerted effort towards forestalling future hazards. This study thus, identified the areas that are susceptibility to floods in parts of the Makera district of the Kaduna South Local Government Area in Nigeria using geospatial techniques. Geographic Information System (GIS) was used to produce thematic layers of the factors contributing to flooding (elevation, slope, drainage density, rainfall, land use/land cover); and a multi-criteria evaluation particularly the “Analytical Hierarchical process” (AHP) was applied to determine the locations at risk. The various thematic layers were integrated into the weighted overlay tool in the ArcGIS 10.3 environment to generate the final susceptibility map. The overlay tool was also used to determine the elements at risk of flood in the study area. The results show that the areas that were highly susceptible to flood constituted about 39% of the study area, while moderate and low vulnerable areas constituted about 26% and 35%, respectively. The result of the multi-criteria analysis revealed that land use/land cover (0.601) was the factor that contributed the most to flooding in the study area based on the criteria weights followed by rainfall (0.470), drainage density (0.326), elevation (0.144), and slope (0.099), respectively. The study recommends that authorities concerned should ensure strict adherence to land use planning act, such that floodplains are avoided during development of any type.


Author(s):  
M. Ocholi ◽  
B. Adeyemi ◽  
O.O. Omojola ◽  
C.S. Samuel

The solar radiation data taken from 14 meteorological stations in Nigeria has been analyzed. The periodic component of the data which covered a period of 13 (mostly 1977-1989) years was removed via Fourier analysis while the residual series was subjected to autoregressive analysis. It was evident from the t-test and autocorrelation plots of the modified (i.e. without the periodic component) series that there exist significant persistence at nine stations including Sokoto, Nguru, Kano, Maiduguri, Bauchi, Yola, Minna, Ibadan, and Benin. The autocorrelation at Jos, Bida, Ikeja, Enugu and Port Harcourt were however found to be insignificant. As the sample partial autocorrelation function cuts off after lag 1, a non-seasonal autoregressive model of order 1, AR (1), was identified for stations with autocorrelation. The Q-statistic of error series suggested that the models were adequate as identified. Moreover, the exploratory plots of the model residual series showed agreement with the quantitative statistics and thus enforces the inference that the models were adequate for monthly mean daily global solar radiation forecasts at some of the study stations. It is interesting to note that all the stations within the sub-sahelian region showed significant persistence whereas all the stations in the coastal region except Benin were found with insignificant autocorrelation. Expectedly, the performance evaluation of the model gave impressive result for the stations within the sub-sahelian region but a relatively weak result for the coastal region. The result for the midland region was mixed whereas it was difficult to conclude on the Guinea savannah region with result from only one station.


Author(s):  
C. Nwakanma ◽  
C. Nmecha ◽  
R.U. Onyeizu

This study assessed the concentrations of heavy metals in soil and surface water from a Lead-Zinc mined pit at Enyigba, Ikwo Local Government Area in Ebonyi State, Nigeria. Soil samples were collected and analysed from different soil depths (0 – 15 cm) and (15 – 30 cm) at a tailing down (marked as TD) and refuse dumpsite (marked as RD) and a vegetation site 50 km away which was used as the control site. Surface water samples were collected from the Enyigba River from three (3) points (marked as point A, B, and C) and were analysed using routine laboratory procedures. The following parameters were analysed for soil: particle size distribution, pH, available phosphorus, total nitrogen, organic carbon, organic matter content, calcium, magnesium, potassium, sodium, exchangeable acidity, and effective cation exchange capacity. The results for mean values of soil samples obtained at both depths were 58.86% (sand), 11.73% (silt) and 34.04% (clay). Mean values obtained for heavy metals from the soil for Iron (Fe) ranged from 3.31 to 2.24 mg/kg: Zinc (Zn) 0.70 to 0.62 mg/kg and Lead (Pb) 0.01 to 0.01 mg/kg). Results obtained for surface water around the mined pit showed mean values for Iron (Fe) 0.57 mg/L, Magnesium (Mg) 151.6 mg/L, Calcium (Ca) 76.62 mg/L, Chlorine (Cl2) 416.6 mg/L and Lead (Pb) 0.01 mg/L. The high concentrations of chlorine make the water unsuitable to be discharged on any agricultural land as plants could accumulate these metals and when consumed could pose serious threat to humans. The discharge from the mining site increased the already slightly high turbidity of the water to a much higher and undesirable level. The mining activity at Enyigba Ikwo LGA, Ebonyi State has negatively impacted the environment through the introduction of heavy metals in soil and surface water, thereby causing an increase in the pollution of the environment. It is recommended that further studies and monitoring should be carried out in the study location for possible remediation.


Author(s):  
L. Hart ◽  
D.D. Basil ◽  
T. Oba

Various factors contribute to the degree of accuracy of the adjusted parameter (coordinate), one of which is the choice of adjustment model. Adjustment models seeks to eliminate (accounts) for the presence of random errors present in a given observations. The choice is critical for surveyors and other spatial analysts for optimal positioning and mapping projects since different adjustment models will yield different level of accuracy of spatial information generated irrespective of the quality of observations. For a traversing network, various adjustment models have been put forward which include; the Transit, the Bowditch, and the Crandels models. In spite of these models, internal consistency and reliability indicators of the network of positions are determined using the least squares adjustment model (observation equation and condition equation models). The aim of this work is to analyze the various traverse adjustment models. The approach deployed in this work was to compute the provisional coordinate of six traverse stations using the approximate methods of adjustment i.e., Bowditch and transit methods of traverse adjustment models. In addition, the least square adjustment models were deployed to minimize the propagation of residuals of the obtained values. The adjusted distances and directions were then compared with the observed distances and directions to obtain the residuals. The coordinate of positions was determined and the Root Mean Square Error (RMSE) associated with the traverse adjustment models are given as 0.128702264 and 0.008560954. Similarly, the RMSE of the adjusted values using the least square models are given as 0.007181432, and 0.005763969 for the observation and condition equation models respectively. The analysis of these results reveals that the traverse adjustment models are unique with capabilities embedded in the determination of the observables during data acquisition. However, for mapping and engineering survey of small locations, the transit method is more preferable to the Bowditch method.


Author(s):  
J. O. Okovido ◽  
C. Kennedy

The probability of earthquake occurrence in the Niger Delta region of Nigeria was studied in this research. The resonant column/bender element tests were used for the study. Series of analysis were carried out on compacted silt in subsoil strata obtained from various locations in Rivers, Bayelsa, Delta and Akwa Ibom States. The effects of confinement on frequency, shear modulus, shear velocity and damping ratio were studied. The tests results revealed that confinement has effects on the investigated parameters. Thus, frequency response increases with increase in confinement pressure. Also, the resonance column test at various confinements revealed changes in shear modulus, accelerometer output and damping ratio. Accordingly, there was high disparity in the tested parameters as confinement pressure was increased. Similarly, the bender element tests also showed that pressure has effect on shear wave-velocity, shear modulus and damping ratio confinement. The shear modulus and shear wave-velocity generally increased as confinement pressure was increased, while damping ratio decreases as confinement pressure was increased. The variations in Resonance Column/Bender Element test parameters showed that the silty soil in the Niger Delta region, an oil and gas rich area, is likely to experience earthquake in the future. Therefore, geological data should be collated for monitoring, especially as several geological activities take place in the region.


Author(s):  
M. Ocholi ◽  
K.E. Ibe ◽  
E.E. Iheonu ◽  
E.E. Ameh

In this study, we have used wind data obtained from an earlier work covering several locations in Nigeria to estimate the possible impact of wind on sound pressure levels. Estimated Weibull parameters were used to compute the most probable wind speed, the average wind speed and the duration for which wind speed exceeds or equal the most probable speed. Adopting the proposed criteria that wind is able to strengthen or weaken sound pressure levels by 3dB depending on wind direction, the effect of wind on sound pressure level was determined. Results showed that wind effect seemed more predominant for the sub-sahelian stations such as Sokoto, Kano, and Maiduguri where the impact was found to be +/- 3dB obviously due to the characteristic high wind speeds recorded at those stations. The situation is almost the same for the midland region except that moderate impacts were found in some of the stations like Yola, Yelwa and Bauchi. However, moderate wind impacts generally characterize the Guinea Savannah and the coastal regions with the exception of Enugu with an impact of +/- 3dB. The result for Warri was found to be insignificant. It was concluded that most locations within the Nigerian environment may attain the wind conditions that would necessitate an adjustment in noise level measurements for application in architectural acoustics. In order to further validate the results of this preliminary study, it was recommended that detailed field survey where all relevant parameters such as wind speeds, wind directions and noise levels are simultaneously measured be conducted.


Author(s):  
F. Ike ◽  
I.C. Mbah ◽  
C.R. Otah ◽  
J. Babington ◽  
L. Chikwendu

The land surfaces of hot-humid tropical urban areas are exposed to significant levels of solar radiation. Increased heat gain adds to different land surface temperature profiles in cities, resulting in different thermal discomfort thresholds. Using multi-temporal (1986, 2001, and 2017) landsat data, this study examined the impact of land use change on urban temperature profiles in Umuahia, Nigeria. The findings revealed that over time, built-up regions grow in surface area and temperature at the expense of other land use. The transfer matrix, showed that approximately 59.88 percent of vegetation and 8.23 percent of bareland were respectively changed into built up during the course of 31 years. The highest annual mean temperature in built-up regions was 21.50°C in 1986, 22.20°C in 2001, and 26.01°C in 2017. Transect profiles across the landuses reveals that surface Temperature rises slowly around water/vegetation and quickly over built-up and bare land area. The study observed drastic changes in land cover with a corresponding increase in surface temperature for the period between 1986 and 2017 with consistent decrease in water bodies and bare land in the study area. Overall, the spatio-temporal distribution of surface temperature in densely built up areas was higher than the adjacent rural surroundings, which is evidence of Urban Heat Island. The impact of landuse change on urban surface temperature profiles could provide detailed data to planners and decision makers in evaluating thermal comfort levels and other risk considerations in the study area.


Author(s):  
C.O. Fakorede ◽  
G.T. Anguruwa ◽  
O.B. Ajayi ◽  
C.A. Odega

Waste generation is inevitable in every human society, although methods of disposal may differ from region to region especially developing and developed nations, yet waste disposal is generally necessary. This study therefore investigated waste disposal practices amongst residents of Oluyole local government area of Ibadan, Oyo State. It was observed that (44.4% ) and (32.4%) of the residents dumped their household refuse with government and private waste collectors respectively, but majority utilized improper waste disposal methods such as dumping in rivers (10.3%), roadsides(14.8%), open dumpsites (20.4%), gutter (9.3%), and open-air burning(33.3%). Larger proportion (97.5%) of the respondents strongly agreed that indiscriminate waste dumping has inimical environmental implications such as flooding, disruption of aesthetic beauty, disease, river pollution amongst others. In order to bring the situation under control, the respondents prefer the full involvement of the government waste collection agency instead of private waste collectors. It is therefore recommended that government waste collector should be empowered to penetrate more traditional core areas for more effective waste collection.


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