6 research outputs found

    Fluctuations in drought occurrence and perceptions of its positive consequences in the Savanna region of Nigeria

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    This study is on fluctuations in drought occurrence and perceptions of its positive consequences in the Savanna region of Nigeria. Data for seventy years (1941 to 2010) on rainfall were sourced from earlier researches for eight selected stations in the study area. The Bhalme and Mooley Drought Index (BMDI) was applied to the data to determine whether or not drought occurred in a particular year. Three different moving averages were applied to the drought series values as depicted by Bhalme and Mooley Drought Index (BMDI). This was done to remove the cyclic, seasonal and irregular patterns (smoothing of the time series) and clearly indicates variations from year to year and any abrupt climatic change in the drought series. Findings revealed various drought intensities in the selected stations during the period of study. Also, a desktop review and perceptions on the positive consequences of drought was carried out with information derived from various stakeholders such as farmers, traders, miners, military personnel and others using focus group discussion, excerpts from journals and books as well as observations by the researcher. This qualitative data and information collaborated the findings of the statistical tools (BMDI and Moving Averages) in the occurrence of drought in the study area and also gave insights into benefits derived from its occurrence by various socio-economic sectors (aviation, trade and commerce, tourism, sand mining, construction, leather work and military activities) of the economy in the study region

    Intensity, duration and frequency of rainstorms in Lokoja

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    This study analyzed the Intensity, duration and frequency (IDF) of rainstorms in Lokoja. Daily rainfall data were collected from Nigerian Meteorological Agency (NiMET). These data were for fifty-five years (1955-2010).The Weibull’s equation was used to plot the return periods of the IDF. The data were fitted to gamma distribution, while the IDF curves were generated using the Gumbel’s distribution. Furthermore, a model expressing the relationship among intensity, duration and frequency of rainstorms for Lokoja was developed. Results showed that the highest annual rainfall in Lokoja in the last 35 years occurred in 1999 with a depth of 1767.1mm with a return period of 36 years while the lowest rainfall occurred in 1982 with an amount of 804.5mm and a return period of one year. The IDF model showed various rainstorm occurrences in Lokoja with their intensities. The highest rainfall intensities are those of relatively low duration (0.2 to 0.7hrs), the medium intensities for 1 to 3hrs durations and the lowest intensities for 6 to 24hrs durations). The highest intensity was that of 0.2 hour (226mm) with a return period of 100 years. The lowest intensity for 0.2 hour was 66.1mm with a return period of 1 year. The IDF curves also confirmed that rainfall intensity in Lokoja decreases with increasing time interval. This study therefore, will be useful in the design of hydrologic facilities like dams and drainage channels.Keywords: Intensity, Duration, Frequency, Rainstorms and Return Perio

    In the Milieu of Planning: The Micro and Meso Scales Climatic Effects in Urban Neighbourhoods in Nigeria

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    In several developing countries, urban centres are emerging at rapid rates. These urban centres are associated with increase in population as well as increase in social and economic activities resulting in the generation of huge wastes. They are also known as areas of intense constructions especially of buildings and roads. Most of these activities result in the cutting down of trees and deforestation thereby making surfaces to be bare or at best paved with bitumen or concrete. All these result in increase in temperature especially in areas within the urban centres without vegetal cover (treeless). This very much is the situation in many Nigerian urban centres including Lokoja North Central Nigeria. This paper posits and shows the contrast in temperature between neighbourhoods that have vegetal covers (tree communities) and those that do not have. It therefore highlights the benefit of the micro scale climatic effect of tree(s) on the meso scale climatic effect of a city or urban centre on itself. It further advocates for the greening of the study area (Lokoja) through the planting of trees, establishment of lawns, urban parks and gardens and the use of green roof options. This position is supported and based on the survey of local resilience strategies and measures used by the respondents and inhabitants of the study area in which 59% of the respondents make use of urban greening options among other coping measures such as lifestyle modification and building modification. Keywords: Micro and Meso-Scales Climatic Effects, Temperature, Urban Heat Island, Thermal Discomfort and Resilience

    Meteorological Drought and Temperature in Sudano-Sahelian Region of Nigeria under Increasing Global Warming

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    This study examinesmeteorological drought and temperature in the Sudano-Sahelian region of Nigeria under increasing global warming. Rainfall data of 60 years (1961 to 2020) and temperature of 40 years (1981–2020) for nine stations were used to quantify drought occurrences as well as the pattern of temperature. The Bhalme and Mooley Drought Index (BMDI) and Student’s t-test were used to indicate if changes have occurred in the amount of rainfall and temperature (increase or decrease) over space and time in the study region. The BMDI was used because it is simple and able to depict historically documented droughts better than other indices. The student’s t-test was used to determine if the sub-period means of the series have altered significantly over time. Results show that the spatial and temporal occurrence and duration varied from one sub-area to another. Also, its intensity was mainly from mild to moderate. Results also show a consistent alternation between drought and wet years over the study period. The trend of temperature shows a tendency towards decreasing temperature during the period of study although it was not significant. The study concludes that the study region experiences climate variability that may well be part of global climate change

    Oral Exposure to Silver/Gold Nanoparticles: Status of RatLipid Profile, Serum Metabolites and Tissue Morphology

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    Study investigated the effect of oral administration of gold-silver nanoparticleson rat biochemical parameters and tissue morphology. Wistar rats weighingapproximately 180±7 g were randomly assigned into four groups. Animals in thecontrol group received distilled water once daily for 30 days while, those in thetreatment groups were administered 10, 50 and 100 mg kgG1 b.wt. gold-silvernanoparticles. The rats were sacrificed under slight anesthesia, 24 h after the lasttreatments. Blood and vital organs including the heart, kidney and liver werecollected and prepared for biochemical and histopathological determinations.Exposure to Ag/Au nanoparticles altered the rat serum lipid profile; lowering theHDL-C while raising the atherogenic index. Exposure of Ag/Au nanoparticles inrats caused significant alteration to the levels of serum albumin, total protein,bilirubin, urea and creatinine. The activities of alanine transaminase, aspartatetransaminase and alkaline phosphatase in rat serum and tissues were alsosignificantly altered by Ag/Au nanoparticles exposure. The histopathologicalexamination revealed inflammation and cellular degeneration caused by exposureto the Ag/Au nanoparticles. We show evidence that Ag/Au nanoparticles elevatedatherogenic index, as well as caused biochemical and morphological alterations,reminiscent of cellular injur