Downstream morphologic characteristics of the alluvial section of lower river Ogun, Nigeria

Rivers constitute an important focus of attention in surface water studies because of their dynamic nature. Therefore, natural rivers develop a wide range of channel forms whose characteristics vary as a function of the position within the fluvial systems. This study examined the river channel morphologic parameters along the alluvial section of River Ogun in South western Nigeria. Data on the channel morphologic variables were collected through field measurement of the bankfull cross sectional characteristics of the river from where the longitudinal characteristics were defined. 48 cross sections were randomly established at bankfull stage along the river channel stretch of 90 km. Bankfull depth and width at each of the cross sections were determined using sonar (electronic sounding machine) that was mounted to a boat. Velocity was measured with the aid of a current meter, while other morphological parameters were estimated from the field data. Analysis of variance revealed that downstream morphological characteristics of the river varies distinctively at each cross section with bedslope as the most significantly varied among all other morphologic parameters (F=91.18; P=0.00). Pearson product moment correlation technique revealed that bankfull width had a correlation of 0.8 and 0.9 with wetted perimeter and cross sectional area respectively while bankfull depth (maximum) had correlations of 0.9, 0.8 and 0.78 with hydraulic radius, wetted perimeter and cross sectional area respectively. The research also revealed that gradient affects the discharge with a positive correlation of 0.9. The study ascertains the extent of variability in the morphologic characteristic of River Ogun which provides scientific basis for river maintenance and management

Sediment dynamics in a small, 2nd order urban River awba cat chment, Ibadan, Nigeria

The sediment dynamics in a small 2nd order catchment of River Awba in the territory of the University of Ibadan, Nigeria was investigated between January and December 2012. The river was gauged by daily measurements of water level as well as sampling of water for determination of suspended sediment load. In this regard, apart from weekly sample, twelve (12) storm flow events which occurred during the day were sampled for determination of suspended sediment concentration. The results showed that during the storms the suspended sediment concentration varied between 636 mg/l in May and 3641.5 mg/l in September, with a mean of 2136.8 mg/l. Also, the value of monthly suspended sediment yield ranged from 10.85 kg in January to 288.4 kg in October with a mean of 89.5 kg. The variability in monthly sediment load closely followed the trend of monthly rainfall in the study area. However, in order to minimize the storm runoff and sediment load generated from the rainstorms events, the paved surfaces within the study catchment should be grassed with the planting of some few tree species. This could further reduce the rate of floods occurrence

Landuse Types within Channel Corridor and River Channel Morphology of River Ona, Ibadan, Nigeria

The importance of river a corridor warrants a well thought out and balanced management approach because it helps in improving or maintaining water quality, protecting wetlands, etc. Hence, this study seeks to identify major landuse types within the River Ona Corridor; examine the impact of these landuse types within the River Ona corridor on its channel morphology and understand the risk being posed by these landuse types. The study is designed by selecting two reaches of six times the average width from each of the four major landuse types that exist along the river corridor. This study revealed that along the downstream section of Eleyele Dam of River Ona, natural forest stabilizes river channel banks, thereby presenting a narrow and shallow width and depth respectively but the widest of all is found at the agricultural zones. 

Downstream Morphologic Characteristics of the Alluvial Section of Lower River Ogun, Nigeria

Rivers constitute an important focus of attention in surface water studies because of their dynamic nature. Therefore, natural rivers develop a wide range of channel forms whose characteristics vary as a function of the position within the fluvial systems. This study examined the river channel morphologic parameters along the alluvial section of River Ogun in South western Nigeria. Data on the channel morphologic variables were collected through field measurement of the bankfull cross sectional characteristics of the river from where the longitudinal characteristics were defined. 48 cross sections were randomly established at bankfull stage along the river channel stretch of 90 km. Bankfull depth and width at each of the cross sections were determined using sonar (electronic sounding machine) that was mounted to a boat. Velocity was measured with the aid of a current meter, while other morphological parameters were estimated from the field data. Analysis of variance revealed that downstream morphological characteristics of the river varies distinctively at each cross section with bedslope as the most significantly varied among all other morphologic parameters (F=91.18; P=0.00). Pearson product moment correlation technique revealed that bankfull width had a correlation of 0.8 and 0.9 with wetted perimeter and cross sectional area respectively while bankfull depth (maximum) had correlations of 0.9, 0.8 and 0.78 with hydraulic radius, wetted perimeter and cross sectional area respectively. The research also revealed that gradient affects the discharge with a positive correlation of 0.9. The study ascertains the extent of variability in the morphologic characteristic of River Ogun which provides scientific basis for river maintenance and management

Sediment Dynamics in a Small, 2nd Order Urban River Awba Catchment, Ibadan, Nigeria

The sediment dynamics in a small 2nd order catchment of River Awba in the territory of the University of Ibadan, Nigeria was investigated between January and December 2012. The river was gauged by daily measurements of water level as well as sampling of water for determination of suspended sediment load. In this regard, apart from weekly sample, twelve (12) storm flow events which occurred during the day were sampled for determination of suspended sediment concentration. The results showed that during the storms the suspended sediment concentration varied between 636 mg/l in May and 3641.5 mg/l in September, with a mean of 2136.8 mg/l. Also, the value of monthly suspended sediment yield ranged from 10.85 kg in January to 288.4 kg in October with a mean of 89.5 kg. The variability in monthly sediment load closely followed the trend of monthly rainfall in the study area. However, in order to minimize the storm runoff and sediment load generated from the rainstorms events, the paved surfaces within the study catchment should be grassed with the planting of some few tree species. This could further reduce the rate of floods occurrence

Community leadership practices in Edo State Nigeria: Justification for a Biomimetic-based alternative in community development

This article is the first of a two-part assessment of leadership practices in community development processes. In this first part, community leadership practices (CLPs) are established as everyday actions executed by community leaders in the administration of processes to achieve communal development. In which case, community development associations (CDAs) should be agents that facilitate community development. Therefore, the continued disbandment of CDAs by the government of Edo State Nigeria in the past 6 years is odd. Postulating that the prevailing anti-development leadership practices is the reason behind the disbandment, the authors assessed the state of CLPs in the study area to determine the justification or otherwise, for a Biomimetic leadership alternative. The assessment was by observation, news reports and document analysis. This article affirmed that dominant anti-development practices of CDA leaders are critical to lack of development and recommended drawing leadership lessons from resilient bio-communities for application in human communitie

Geospatial analysis of changes in vegetation cover over Nigeria

Vegetation cover over Nigeria has been on the decrease recently, hence the need for adequate monitoring using geo-information technology. This study examined the spatio-temporal variation of vegetation cover over Nigeria for thirty years with a view to developing a strategy for enhancing environmental sustainability.  The study utilized satellite imageries between 1981 and 2010 using Normalised Difference Vegetation Index (NDVI) to predict the spatial extent of vegetation cover in 2030 coupled with cellular automata and markov chain techniques in ArcGIS 10.3. The results showed that dense vegetal areas decreased from 300,959.48 km2 in 1981 to 46,662.30 km2  in  2010,  low vegetal areas increased from 35,305.33 km2 in 1981 to 364,533.77 km2 with a further increase of 422,429km2 from the 2030 prediction

Democratic leadership practices in Edo State Nigeria: A justification for a Biomimetic-based democratic alternative

This article - the last of a two-part assessment of leadership practices in community development processes, noted that since Nigeria’s independence 6 decades ago, only the past 2 decades has experienced uninterrupted democracy. Considering the importance of ideal democratic processes in actualizing progressive community development, the paper examined participation in politics, relative to leadership among geese to justify the need for nature-based alternative leadership practices in egalitarian developing communities. Analysis of empirical evidences from literature was used to evaluate key leadership issues, discuss political situations, and models of citizens’ participation across Edo State communities in Nigeria. Observed democratic leadership in the study area turned out as “practices that are alien to democracy” because it lacked the basic tenets of democracy. Several indices of participation in politics were articulated and matched against practices among the geese towards articulating a Biomimetic-based Democratic Leadership Practices for community progression. Recommendations were made and implication drawn

A novel plasmid carrying blaCTX-M-15 identified in commensal Escherichia coli from healthy pregnant women in Ibadan, Nigeria

AbstractThe aim of this study was to investigate the molecular characteristics of commensal Escherichia coli producing extended-spectrum β-lactamases and showing fluoroquinolone resistance circulating in a healthy population in Ibadan, Nigeria. In total, 101 faecal samples from healthy pregnant women on the day of admission to hospital were collected and plated on eosin–methylene blue agar supplemented with cefotaxime. Genotyping demonstrated the presence of the blaCTX-M-15 gene in all of the cefotaxime-resistant isolates (n=32), and there was circulation of prevalent clones. The aac(6′)-Ib-cr, qnrS1, qepA1 and qnrB1 genes were identified in several strains. A novel plasmid supporting the spread of the blaCTX-M-15, blaTEM-1 and qnrS1 genes was identified in these isolates by complete DNA sequencing