19 research outputs found

    Reliability assessment of Thomas Fiering's method of stream flow prediction

    Get PDF
    This study was carried out to assess the reliability of Thomas-Fiering’s method of stream flow prediction. The 19 years gauged data of 1955-1973 was extended to 2016 using the model. Model calibration was done by multiple linear regressions of the gauged and synthetic data of 1956-1973. The linear equations developed for January to December were used for adjustment of the three sets of stream flow data generated for 1974-2016. The reliability assessment was done based on the extent to which the unbiased statistics (mean, standard deviation and correlation coefficients) of the 1955-1973 stream flow data were preserved in the synthetic stream flow for 1955-2016. The comparison was done using linear regression and One-Way ANOVA (95% Confidence level) to check for the reliability of the generated data. The coefficients of determination, P-values, F-values and critical F-values were used to estimate the reliability index. Synthetic data was found to be 95.9% reliable.Keywords: Ofu River, Reliability, Stream flow, Synthetic, Thomas Fiering’s mode

    Assessment of the change in river discharge-carrying capacity using remote sensing geographic information system: a case study of Ofu river, Nigeria

    Get PDF
    This study assessed the changes in the flow carrying capacity of Ofu River in Nigeria between 2000 and 2011 using the DEMs of the respective years. The results showed that Ofu River had lost 12.88 m amounting to about 42.58 % of its flow depth at Oforachi between 2000 and 2011 at a rate of 1.171 m per year and an estimated 18.74 m amounting to about 61.95 % in 2016. The Total sediment load was 66,825,730 kg/year comprising of 56,747,260 kg/year and 10,077,470 kg/year of measured and unmeasured sediment loads respectively. The results obtained suggested that the loss in flow depth is a result of siltation of the river bed due to the high sediment load probably as a result of soil cultivation within the floodplains. The study demonstrated that remote sensing and GIS can be used to assess the changes in the discharge-carrying capacity of a river.Keywords: DEM, Discharge capacity, Flow depth, GIS, Ofu river, Sediment loa

    Assessing genetic diversity and phylogeographic structure of duck (Anas platyrhynchos) in Nigeria using mitochondrial DNA D-loop sequences

    Get PDF
    In this study, the maternal genetic diversity and phylogenetic relationship of Nigerian duck populations were assessed. A total of 591 base pair fragment of the mitochondrial DNA (mtDNA) D-loop region of 87 indigenous ducks from two populations in Nigeria were analyzed. Seven haplotypes and 70 polymorphic sites were identified. The mean haplotypic and nucleotide diversity were found to be 0.381±0.058 and 0.315±0.155 respectively. The phylogeny revealed two divergent haplotype clades, suggesting two possible maternal lineage in Nigerian duck population, with the most commonly shared haplotype belonging to Mallard ducks (Anas platyrhynchos). Genetic variation within and between populations accounted for 63.32% and 36.68% of the total genetic variation respectively. This study concluded that there was relatively high genetic diversity and differentiation, thus, this information will probably pave way for further evaluation studies, preservation and improvement of Nigerian ducks as genetic resources.Keywords: Genetic Diversity, MtDNA, Nigerian duck, phylogen

    Assessment of the Effect of Land Use /Land Cover Changes on Total Runoff From Ofu River Catchment in Nigeria

    Full text link
    The total runoff from a catchment is dependednt on both the soil characteristics and the land use/land cover (LULC) type. This study was conducted to examine the effect of changes in land cover on the total runoff from Ofu River Catchment in Nigeria. Classified Landsat imageries of 1987, 2001 and 2016 in combination with the soil map extracted from the Digital Soil Map of the World was used to estimate the runoff curve number for 1987, 2001 and 2016. The runoff depth for 35 years daily rainfall data was estimated using Natura Resource Conservation Services Curve Number (NRCS-CN) method. The runoff depths obtained for the respective years were subjected to a one-way analysis of variance at 95% level of significance. P-value < 0.05 was taken as statistically significant. Runoff curve numbers obtained for 1987, 2001 and 2016 were 61.83, 63.26 and 62.79 respectively. The effects of the changes in LULC for 1987-2001, 2001-2016 and 1987-2016 were statistically significant (P<0.001) at 95% confident interval. The average change in runoff depths were 79.81%, -11.10% and 48.09% respectively for 1987-2001, 2001-2016 and 1987-2016. The study concluded that the changes in LULC of the catchment had significant effect on the runoff from the catchment

    Human factors influencing contractors' risk attitudes: a case study of the Malaysian construction industry

    Get PDF
    Malaysia is one of the most rapidly developing countries among developing nations. The construction industry has played a major role in Malaysia’s rapid economic growth. Among the major sectors in Malaysia, the importance of the construction industry is unique regardless of the level of the country’s development. However, the attitude of the construction industry in Malaysia towards managing contractors’ risk attitudes is very weak. The introduction of the Occupational Safety and Health Act in 1994 by the Malaysian government made all industries in Malaysia to identify risks, conduct risk assessment and control risk. In addition, the Malaysian construction industry simultaneously implemented an integrated system to ensure consistency and better performance of projects. To identify the factors influencing contractors' risk attitudes, relevant literature was reviewed, and a questionnaire survey was conducted. This study focused on the G7 contractors operating in the Malaysian construction industry. One hundred and nineteen copies of a structured questionnaire were analysed with a response rate of 85%. Structural equation modelling was utilized to test the hypotheses developed for the study. Results showed that government policies played a moderating role in enhancing the relationship between human-related factors affecting contractors’ risk attitudes in the construction industry

    Application of Analytic Hierarchy Process and Geographic Information System Techniques in Flood Risk Assessment: A Case of Ofu River Catchment in Nigeria

    Get PDF
    Flood risk assessment of Ofu River Catchment in Nigeria was carried out by integration of thematic maps in ArcGIS 10.2.2. Analytic Hierarchy Process (AHP) was applied in the decision making and ranking of flood causative factors before their integration for development of hazard map in ArcGIS. The social and physical vulnerability of the catchment were considered in the development of the vulnerability map. The flood risk map was developed as a product of the hazard and vulnerability map. The results showed that the land areas within the Very High and High Risk zones were respectively 163.07 km2 and 392.63 km2 with Igalamela/Odolu Local Government Area (LGA) accounting for about 62% and 31% respectively. A total of 19, 034 and 47,652 persons are respectively at very high and high risk of flood within the catchment. Oforachi community in Igalamela/Odolu LGA and Ejule Ojebe Community in Ibaji LGA both in Kogi State are respectively at Very High and High Risk of Ofu River flood. High Impacts were recorded by about 35% and 52% of Oforachi Community during the 1995 and 2000 historical flood events. A watershed management plan is therefore required to prevent the serious damage experienced in previous flood events

    EOSINOPHILIC MENINGITIS IN A 10-YEAR OLD NIGERIAN BOY: A CASE REPORT

    Get PDF
    Eosinophilic meningitis is rare, commonly caused by invasion of the central nervous system by helminthes. The present case is that of a 10–year–old boy who presented with history of generalized pruritus not associated with skin eruptions, followed by pain and weakness of the extremities and loss of consciousness. Patient did not receive BCG vaccination. Initial clinical evaluation was suggestive of tuberculous meningitis but cerebrospinal fluid analysis revealed eosinophilic meningitis. Patient made remarkable improvement with treatment with no sequel

    Hydrologic and Morphometric Analysis of Ofu River Sub-Basin using Remote Sensing and Geographic Information System

    Get PDF
    The morphometric characteristics of a river basin are very important factors in watershed hydrology. The morphometric analysis of the Ofu River sub-basin was carried out in this study to assess its morphologic and hydrological characteristics as well as its flood potentials based on the morphological characteristics. The study was carried out using remotely sensed spatial data analysed using Geographical Information Systems (GIS). The morphometric parameters analysed were the areal, linear, and relief aspects of the sub-basin. The results showed that Ofu river sub-basin covers a total area of 1604.56 km2 and a perimeter of 556.98 km covering parts of Kogi and Enugu States in Nigeria. The sub-basin has 3rd order river network based on the Strahler’sclassification with a dendritic drainage pattern and moderate drainage texture. The values of bifurcation ratio, drainage density, circularity ratio, elongation ratio, form factor, stream frequency and drainage intensity indicate that the sub-basin is elongated and would produce a flatter peak of direct runoff for a longer duration implying that the sub-basin is morphometrically less susceptible to flood and that any flood flow that may emanate from it would be easy to manage

    Development of Rating Curve for Ofu River at Oforachi Hydrometric Station

    Get PDF
    The stage-discharge rating curve is widely used in the research for analysis of flow regime and design of hydraulic structure and river channel where the measurement of discharge is difficult especially in developing countries like Nigeria. This study sought to develop a stage-discharge relationship for Ofu River in Nigeria where water resources project planning has been limited by the unavailable of stream flow data. Discharge Measurement was carried out using Valeport Current meter while stage was measured using staff gauge at Oforachi Bridge hydrometric station from February, 2016 to January, 2017. The Stage and discharge results were used to determine the curve coefficient via regression analysis and finally the rating curve equation for the river at this station. The Oforachi Bridge serves as the permanent control, thus the curve is reliable

    Examining technology orientation constructs: A validation study

    Get PDF
    This study validates technology orientation (TO) constructs in the Malaysian construction industry context. Using a well-structured online-administered questionnaire, the data was collected from one hundred and eighty-five representatives of Grade 7 (G7) construction firms comprises of top or middle management level who are involved in the day-to-day running of the firm as well as taking strategic decisions about how the firms are been run like CEO, Executive Director, Managing Director, Construction Managers, and Project Managers). The data was analyzed using Smart-PLS 3 software. Results of this analysis revealed that all the technology orientation’s dimensions namely, technology capability, top management capability, learning (commitment to learning), and unlearning (commitment to change) were highly applicable. Acceptable level of internal consistency, reliability, discriminant validity, and convergent validity for each of the constructs of the technology orientation was established. Based on the outcome of the analysis, it is therefore recommended that the TO instrument are suitable for measuring all the constructs of TO to study how Malaysian construction firms can combine their capabilities to build the assets of the organization and allow them to be utilized in a wellorganized and efficient way
    corecore