Open Access Case Study

Community Approach to Growing Greener Cities through Self-help Street Horticultural Gardens: A Case Study of Lagos, Nigeria

Albert Ayorinde Abegunde

International Journal of Environment and Climate Change, Page 103-117
DOI: 10.9734/BJECC/2011/427

The study examines residents’ concerns in greening their communities though self-help initiatives (SHI) carried out by individuals who utilise road set-backs to plant street horticultural gardens (SHG) in Eti-osa Local Government Area, Lagos, Nigeria. It purposefully administered questionnaire to managers of all SHG in the study area to establish their socio-economic characteristics, contributions to community greening and motivating factors behind their SHI. The study found that the horticulturists were nearly males (93.7%), young adults (54.0%), earning about three dollars per day (63.6%), have been in practice for more than four years (79.3%) and altogether using about 1.5% of land in the study area for SHG. A good number of them have contributed to voluntary greening of their communities through planting of trees (76.2%), hedges and shrubs (47.6%) and flowering plants (65.1%). The horticulturists’ Motivating Index (HMI) employed to know why they went into the practice revealed that they (51%) were moved by the depreciating state of urban green (HMI=2.55) and feared (46.4%) the impending ecological doom on the built environment due to lack of sufficient green space, causing global warming (HMI=2.32). This could be why the linear regression test of the preference of social to economic value of the practice of SHG in the study area has its R2 to be 0.219. This means that SHG in the area did not necessarily bring positive economic value to the horticulturists as the social value embedded in it. This study is a prove that literature and publicities on environmental effects of global reduction in green space seem to be yielding positive results in Africa as some individuals in the study area are taking into self-help initiatives in community greening, even where land seemed very scarce for such development. It concludes that literature on the subject should be more encouraged.

Open Access Original Research Article

Application of Harmonic Analysis in the Preliminary Prediction of Air Temperature over Lagos and Abuja, Nigeria

B. C. Isikwue, O. I. Agada, E. U. Utah, F. N. Okeke

International Journal of Environment and Climate Change, Page 53-65
DOI: 10.9734/BJECC/2011/353

Harmonic Analysis technique has been employed in predicting the hourly air temperature variations over Lagos and Abuja, Nigeria. The variations in hourly air temperatures over the two stations are periodic and thus have strong tendency of being repeated the next day, if all other atmospheric variables are constant. It was observed that the variation in hourly air temperature in the two stations is dominated by the first harmonic, thus it fluctuates by one cycle with a period of 24 hours. Invariably, harmonic equations could be applied to hourly temperature prediction even on a large scale data. The maximum hourly air temperature occurred two hours on the average after the maximum solar irradiance has occurred in each station. It was found that the temperature of the air at a particular hour is dependent on that of the previous hour.

Open Access Original Research Article

Effect of Depth on Microbial Pollution of Shallow Wells in Makurdi Metropoilis, Benue State, Nigeria

M. O. Isikwue, D. Iorver, S. B. Onoja

International Journal of Environment and Climate Change, Page 66-73
DOI: 10.9734/BJECC/2011/354

This study looked at the effect of depth on the microbial pollution of shallow wells in the three floodplains of Makurdi metropolis of Benue State, Nigeria. Water samples from the wells were collected and analyzed monthly for seven months from February to August (covering both wet and dry seasons) using the pour plate technique. The assessment was for the presence coliform bacteria. The species isolated were Salmonella typhilis, Escherichia coli, Streptococcus faecalis, Proteus spp. and total coliform. The pollution of wells was found to increase with decrease in depth and decrease with increase in depth. The water table varied from 4.3m (in wet season) to 6.4m (in dry season). Generally pollution level in the floodplains was between 17cfu/ml and 297cfu/ml of bacterial population. No well studied met the limit by World Health organization (WHO) for drinking water which is 0cfu/ml and 10cfu/ml by the National Agency Food and Drugs Administration and Control, Nigeria (NAFDAC). This shows that wells must be up to 15m deep so as to be free from pollution. Screening the wells to the depth of 15m and treatment by disinfection before drinking were the recommendations made.

Open Access Original Research Article

Determination of the Contamination of Groundwater Sources in Okrika Mainland with Polynuclear Aromatic Hydrocarbons (PAHs)

D. H. Ogbuagu, C. G. Okoli, C. L. Gilbert, S. Madu

International Journal of Environment and Climate Change, Page 90-102
DOI: 10.9734/BJECC/2011/408

In this study, we examined the presence and concentrations of six polynuclear aromatic hydrocarbons (PAHs) in groundwater sources of Okrika mainland impacted by effluent discharges from a petroleum refinery into her surrounding Creeks. Sterile amber coloured bottles were used to collect 10 replicate borehole water samples from the mainland and fixed with concentrated H2SO4. Samples were transferred to the laboratory in iced coolers and analyzed using Gas chromatography coupled with Flame Ionization Detector (GC-FID). The interactions of the PAH components detected was determined using the Pearson product moment correlation coefficient (r) while spatial variance equality in means of concentrations was explored with the One-way ANOVA. Structure detection of observed inequalities was made with means plots. Concentrations of the PAHs were high and exceeded the WHO maximum permissible limit of 0.002mg/l in drinking water. Benzo(b)fluoranthene, with the highest mean concentration varied between 0.00037-0.51266 (0.08117±0.03330159)mg/l, fluoranthene varied between 0.00060-0.32890 (0.0473946±0.01769877)mg/l, while benzo(k)fluoranthene with the least mean concentration varied between 0.00017-0.08478 (0.0237385±0.00610045)mg/l. However, pyrene concentration ranged between 0.00015 and 0.24757 (0.0508440±0.01859716)mg/l, benzo(a)anthracene between 0.00020-0.21972 (0.0512660±0.01688275)mg/l, and chrysene between 0.00013 and 0.16571 (0.0488975±0.01090264)mg/l. Strong associations were observed between all the PAH components measured at P<0.01. Significant heterogeneity in mean variance of the PAHs [F(211.9502)>Fcrit(3.921478)] was recorded across the sampling locations at P<0.05. Structure detection of mean difference revealed that the inequalities were most contributed in BH1, BH 2, BH 5 and BH 10, while equality in mean concentrations were observed between BH 1 and BH 4, and BH 5 and BH 6. BH 8 recorded the highest contamination level of the various PAHs due basically to its proximity to the refinery’s effluent channel. The most probable source of these PAHs is therefore the nearby Port Harcourt Refinery Company’s effluent discharges into the surrounding creeks of the mainland. This contamination is of public health concern as several PAHs are known carcinogens. It is recommended that advanced technological engineering be applied to contain the presence of these pollutants in drinking water sources of residents of the area.

Open Access Review Article

Global Climate Change: A Threat to Food Security and Environmental Conservation

O. M. Agbogidi

International Journal of Environment and Climate Change, Page 74-89
DOI: 10.9734/BJECC/2011/206

Rapid socio-economic changes in some developing countries like India, China, etc., are influencing dramatically the fuel consumption pattern world over. An increase of 880 TWh of electricity consumption in transport in 2030 compared with the Reference Scenario, of which 90% occurs in PLDVs, results in about 250 Mt of additional CO2 emissions. The rise in the amount of CO2 in the atmosphere is 1.0 – 3.5°C (1PCC, 2007a). If emissions of greenhouse gases, and in particular CO2, continue unabated the enhanced greenhouse effect may alter the world’s climate system irreversibly. This review attempted to examine how climate change constitutes a threat to food security and environmental conservation. Climate change (CC) refers to changes in modern climate. It reflects abnormal variations to the expected climate within the earth’s atmosphere and subsequent effects on other parts of the earth. It is emphasized that CC poses a threat to food security as it impacts on natural systems and resources through erratic rainfall patterns, heightened temperature and susceptibility to pest and disease outbreaks hence decreasing crop yields and consequently increased hunger. CC negatively affects biodiversity conservation and management through exacerbated drought conditions, increased risk of wildfires leading to some extreme events like heat, waves, river and coastal flooding, landslides, storms, hurricanes and tornadoes which culminate in environmental degradation. For its effects to be reduced establishment of more forest plantations and maintenance of the existing natural and artificial forests should be encouraged. Saving biodiversity in the form of standing forests and interact lands can help prevent climate change and help communities and natural areas cope with a changing planet. At the same time, helping nature become more reification climate change through a combination of management restoration and protection strategies will help prepare places, plants, animals and people for climatic change successful adoption of living system can help ensure their ability to support the needs of people and better withstand future changes.