Imo River Basin Research Articles

The Epidemiological, Entomological and Socio-Economic Evaluation of Ivermectin Treatment in Imo River Basin, Nigeria

To assess the effectiveness of annual mass ivermectin treatment over 20 years in achieving elimination of onchocerciasis, we conducted a cross-sectional study between May 2021 and March 2022. A total of 540 individuals aged 5 years and above from rural farming communities selected were skin-snipped for dermal microfilariae (mf) by standard technique. Prospection of Simulium black flies was done at Lolo and Ibii Rivers. Structured questionnaires were used for the level of awareness, attitude and perceptions (KAP): onchocerciasis, vectors, treatment, drug compliance, benefits and socio-economy. Results revealed an overall mf prevalence of 12.8% and black fly infection rate (0.7%), infectivity and transmission potentials of (0.0%) indicative of non-transmission. These values contrasted with earlier reports in the range of 22%-68% for mf and 20.2%-48.2% infective rates suggesting the efficacy of mass ivermectin treatment in halting onchocerciasis. Participants had a high level of awareness about drug distribution. Benefits, dislikes and challenges of ivermectin were reported. We concluded that annual mass ivermectin treatment creditably reduced the microfilarial load and treatment in the study communities.

Updated Profile of Clinical Manifestations of Onchocerciasis after Repeated Ivermectin Treatment in Middle Imo River Basin, Nigeria

We conducted a cross-sectional survey on the impact of ivermectin after repeated treatment in five communities in Imo State, Nigeria. Rapid epidemiological mapping of onchocerciasis (REMO) carried out in 450 subjects in 1994 prior to the launching of mass drug administration were compared with re-examinations of 540 subjects in 2023. We found palpable nodule reduction from 47.2% to 12.2% and popular dermatitis decreased from 42.9% to 5.9%. Reductions in other clinical features were observed. Overall, a significantly higher proportion of males were infected than females (P<0.05). The implications of these results were discussed in line with the reported benefits of ivermectin therapy.

Groundwater Risk Assessment in Imo River Basin of Southeastern Nigeria Using GIS-Based DRASTIC and GOD

Groundwater Risk Assessment in Imo River Basin of Southeastern Nigeria Using GIS-Based DRASTIC and GOD

Estimates of aquifer hydraulic conductivity based on grain-size data and multiple regression techniques in Imo River Basin

Estimates of aquifer hydraulic conductivity based on grain-size data and multiple regression techniques in Imo River Basin

Respondent’s Perception on Anthropogenic Determinants of Gully Erosion in Upper Imo River Basin (UIRB), Southeastern Nigeria

Respondent’s Perception on Anthropogenic Determinants of Gully Erosion in Upper Imo River Basin (UIRB), Southeastern Nigeria

Homogeneity in Aquifer Vulnerability Index (AQI) and Water Quality Index (WQI) around some selected dumpsites in Imo River Basin Southeastern Nigeria

This study was carried out using vertical electrical sounding data and geochemical data to determine if there is a relationship between the aquifer vulnerability index and the water quality index in the Imo River Basin Southeastern, Nigeria. Some vertical electrical sounding data were collected using OMEGA SAS1000 Terrameter, and sixteen (16) water samples were collected from, both surface and groundwater around the three selected dumpsites from Owerri, Orlu and Okigwe areas. These two sets of data were used to evaluate the water qualities in the vicinity of the three active dumpsites. The DRASTIC index ranged between 59 and 199, and the spatial variation showed that 8.8% of the aquifer in the study area is highly vulnerable. 81.2% of the aquifer has a low vulnerability index. The water quality index in the study area showed both good and poor water qualities. The geospatial distribution of water quality index showed that 80% of the study area had good water quality, and the remaining 20 % of the study area had poor water quality. The bivariate regression showed a curvilinear, relationship between the aquifer vulnerability index and the water quality index

Transmission potentials status of simulium damnosum and willingness to comply with Ivermectin Treatment in Imo River Basin, Nigeria

Entomological, quantitative and qualitative data collection on willingness to comply with ivermectin treatment was conducted between May 2019 and March 2020 in Imo River Basin Nigeria. Simulium damnosum collected at Rivers Lolo and Ibii breeding sites by human-bait technique was assessed for transmission indices by standard methods. Structured questionnaires were used to ascertain compliance levels by communities (Umulolo and Amuro) and willingness to sustain the long-term ivermectin treatment. Entomologic indices (overall and specific for both sites) showed that infection, infective and parous rates were 0.7% (0.6% versus 0.7%), 0.0% (0.0% versus 0.0%), and 21.0% (22.3% versus 19.9%) respectively. Monthly biting rate (MBR) and monthly parous biting rate (MPBR) were 6,779.25 (3,291.75 versus 3,507.75) and 1,427.25 (770.0 versus 657.25) bites/person/month. Monthly transmission potentials (MTP) were zero indicative of no transmission. Of the 458 interviewed, 31.6% and 68.3% were males and females respectively. Among them, 66.8% were males and 67.4% were females treated before and 21 (14.5%) and 38 (121.1%) were high compliers. Sex did not affect the rate of compliance (p>0.05). Age group 25 years and above (74.3%) had been treated before with 21.3% high compliers among age groups. Analysis of data revealed that age significantly affected the intake of drug (p0.05). Suggested ways to improve compliance were documented and findings discussed in the context of possible onchocerciasis elimination.

Gully Morphological Assessment and Anthropogenic Determinants in Urban and Rural Settlements of Upper Imo River Basin (UIRB) South Eastern Nigeria

Gully erosion have been proven to vary both in terms of size and number in urban and rural settlements and is caused by factors related to both human and natural phenomenon. This study assessed the gully morphological development in an urban and rural settlement with the view of finding the settlement that is more vulnerable to gully erosion development. It investigated gully development in the urban and rural settlements of UIRB; gully morphological features in settlements; and the anthropogenic factors of gully development in urban and rural settlements. A reconnaissance survey was carried out in 2016, while a detailed field survey on the sampled locations and gully sites was carried out from 2017 till early 2019. Two types of data were employed in this study. They were primary and secondary (archival) data. The secondary data set used for this study was obtained from maps (topographical and lithological) and satellite imageries obtained from USSG. Primary data used for the study were grouped into two-gully morphological data and anthropogenic data. The two data sets were obtained through field measurement, digital image analysis, and a questionnaire survey. The morphological data considered are gully length, width, depth, area slope, and elevation, while anthropogenic data involves human economic activities. The sampling technique employed was randomized systematic sampling. Three major factors considered in the course of sampling were settlement type, the number of second-order basins located within the various settlements of the upper Imo River basin, and several gullies located in the settlements of UIRB. Considering these factors 18 gully sites were randomly sampled from gullied second-order basins. Data analysis makes use of percentages, measures of variations, t-tests, and levene statistics. Results of the analysis showed that gully erosion in UIRB develops both in urban and rural settlements. 61.1% of the gullies develop in rural settlements, while 39.9% 0f the gullies develop in urban settlements. The total length, width, and area of the sampled gully sites in Upper Imo River were 6213.2 m, 1931.1, and 330,005.6 m2 (330 km2) respectively. Out of these values, the total length, width, and area found in the rural area was 3,539.2, 863.5 m, and 91,767 m2 (91.8 km2) respectively, while the total length, width, and area in the urban area was 2,674, 1,067.9 m and 238,238.4 m2 (238.2 km2) respectively. The slope where gullies are located in rural areas ranges between 84.4-89.8%, while the slope where gullies are located in urban areas of UIRB ranges between 89.4-89.7%. The elevation where gullies develop in rural areas falls between 55-142 m, while the elevation where gullies are located in urban areas ranges from 55-89.9 m. In terms of number, more gullies are fun in rural settlements than in urban settlements, but in terms of intensity and threat, they are higher in rural areas than in urban areas. Failed road construction was the major factor of gully erosion initiation and development in the urban areas, while sand mining was the major factor of gully erosion in the rural areas of the upper Imo River basin. The two major contributors to gully erosion development in the urban area were failed road construction and sand mining, while the two least contributing factors of gully erosion in the urban areas of the study area were stone mining and farming activities.

Onchocerciasis transmission indicators following long-term ivermectin treatment in Imo river Basin, Nigeria

Onchocerciasis transmission indicators following long-term ivermectin treatment in Imo river Basin, Nigeria

Soil Erosion Susceptibility Mapping of Imo River Basin Using Modified Geomorphometric Prioritisation Method

Abstract Gullies and other forms of erosion have been the greatest environmental problem and catastrophe in most high- and low-income countries. The challenge posed by soil erosion has compromised agricultural productivity, environmental biodiversity and food safety for the world's population. It is important to identify vulnerable areas to soil erosion in each region to initiate remedial measures. This study demonstrates the use of watershed morphometry coupled with weighted sum analysis (WSA) to estimate the soil erosion susceptibility of the Imo River Basin sub-watersheds (SWs) in South-Eastern Nigeria using satellite remote-sensing data and geographic information system (GIS) analysis. To this end, Shuttle Radar Topography Mission (SRTM), a Digital Elevation Model (DEM) with 30 m spatial resolution was used to extract and analyse 18 morphometric parameters including basic, linear, shape and relief. The method of receiver operating characteristics (ROC) curves was used to validate the model's prediction accuracy. This morphometry-based analysis resulted in the SWs being classified into zones of low, medium, high and very high erosion susceptibility. With regard to erosion susceptibility, 41.51% of the basin (2494.68 km2) is in the very high priority zone; while 10.50%, 44.33% and 3.66% of the basin are in the high, medium and low priority zones respectively. Validation of the final erosion susceptibility map showed a prediction accuracy of 81%. The use of satellite imagery and morphometric analysis in this study was cost- and time-effective for identifying areas susceptible to soil erosion.

The pollution status and effects of seasonal changes in rivers within Imo River Basin, Southeastern Nigeria

The pollution status and effects of seasonal changes in rivers within Imo River basin were studied between October 2015 and September 2016. Water samples and 4 species of fish samples were collected from seven rivers: Otanmiri, Nwaorie, Njaba, Blue Lake Oguta, OrashiOpuomo and AbubaUnuchi, using suitable sterile containers. The water and fish samples were analysed bacteriologically using culture technique and the method of (1) for physico-chemical parameters. The findings revealed that 11 genera of bacteria Staphylococcus species, Streptococcus faecalis, Micrococcus species, Aeromonas species, Vibrio species, Salmonella species, Proteus mirabilis, Escherichia coli, Flavobacterium species and Klebsiella species were present in the water and fish samples examined. The total heterotrophic bacteria count (THBC) of the rivers during the raining season ranged from 2.3 x 106 to 2.9 x 106cfu/ml and 2.02 x 105 to 2.6 x 105cfu/ml in the dry season. For the fish samples, the THBC ranged from 1.86 x 105 to 2.4 x 105cfu/ml in the raining season and increased to 2.3 x 105 to 2.8 x 105cfu/ml in the dry season. The physico-chemical parameters of the watersamples: cadmium, lead, mercury, nitrate, sulphate, phosphate and copper were found to be higher than WHO standard for drinking water, especially during the dry season. The prevalence of physically observed fish diseases generally increased from 35.6% percent in the raining season to 74.4% in the dry season. The study has established high pollution of rivers within Imo river basin and adverse effects of seasonal changes on aquatic organisms in the rivers due to pollution.

Evaluation of soils on a toposequence formed from the coastal plain sands of the Imo river basin, Southeastern Niger

Due to the increasing land degradation in southeastern Nigeria – with particular reference to the ubiquitous gully network in the region – selected soils formed from the Coastal Plain Sands of the Imo River Basin were evaluated and characterized to determine their potentials and capabilities. , Three profile pits were consequently dug on the upper slope (Umuariam), -mid-slope (Umulogho), and foot slope (Umungwa) of three towns on the Imo River Basin underlain by the coastal plain sands. The soil color ranged from greyish brown (5 YR 5/2) to dull brown (7.5 YR 5/3) in the topsoil and from dull orange (5 YR 6/4) to orange (5 YR 6/7) in the subsoil. The soils had sandy topsoil and relatively more clayey subsoil. The pH (in KCl) ranged from very strongly acidic (4.5 – 5.0) to moderately acidic (5.1 – 6.0). They had low organic matter, low total nitrogen, low ECEC, low Al saturation, and moderate base saturation. The soils of Umuariam (Upper Slope) and Umulogho (Mid Slope) were classified as Typic Hapludults (Chromic Acrisols), while that of Umungwa (Foot Slope) was classified as Typic Udipsamments (Rubic Arenosols). Umuariam had a USDA land capability class of IIes and a USBR land capability class of 2v/C. Umulogho and Umungwa both had a USDA and USBR capability class of IVs and 3v/C respectively. Though moderately to marginally irrigable, the soils can still produce increased and sustainable agricultural yield if the appropriate land use and husbandry practices are adopted, with particular reference to erosion control, organic manure, lime, and fertilizer application.

Geo-hydraulic evaluation of aquifers of the Upper Imo River Basin, Southeastern Nigeria using Dar-Zarrouk parameters

Aquifer geo-hydraulic evaluation of the Upper Imo River Basin, Southeastern Nigeria, was carried out to estimate aquifer parameters from surface resistivity data. Forty (40) vertical electrical sounding data were acquired with the ABEM™ Terrameter SAS 4000 using the Schlumberger array with a maximum current electrode separation of 1000 m. Seven (7) parametric soundings were carried out close to the location of existing boreholes with pumping test data to geologically constrain the predictive process. The vertical electrical sounding data were processed using a combination of curve matching and computer modeling using the OFFIX™ Software. Aquifer resistivity of the study area ranged between 136 and 4640 Ωm. The depth to water table varies between 23.6 and 94.5 m, while the aquifer thickness varies between 1.7and 126.2 m with Ibeku and environs having the thinnest aquifers. Estimates of the Dar-Zarrouk parameters revealed that the transverse resistance varies between 534.8 and 196,092 Ωm2, while the longitudinal conductance ranged between 0.001737 and 0.7211 Ω−1. Estimates of the geo-hydraulic parameters using Dar-Zarrouk parameters calibrated with local geology revealed that aquifer hydraulic conductivity ranges from 1.902 to 42.85 m/day and 0.4195 to 5.339 m/day for the areas underlain by the Benin and Ameki Formations, respectively. Similarly, aquifer transmissivity values on the other hand ranged between 71.97 and 1810.91 m2/day and 1.448 and 424.985 m2/day for the Benin and Ameki Formations, respectively. The range of aquifer hydraulic parameters interpreted in the study area revealed that the groundwater potentials of the area vary from fair to good with the areas underlain by the Benin Formation having higher groundwater potentials.

Comparative Evaluation of Swine Production With Other Domestic Livestock in Mbaitolu Local Government Area of Imo State, Nigeria.

The researcher has undertaken this study on comparative evaluation of swine production with other domestic livestock in Mbaitolu Local Government Council of Imo State, Nigeria to proffer some solution to the problems hindering the rearing of swine in the study areas (Mbieri, Ogwa, Orodo, Ogbaku, Eziama –Obiato, Umunoha, Ifakala, Ubomiri and Afara). The researcher used descriptive survey design to carry out the study. The population for the study was 10,450 respondents drawn from nine towns of Mbaitolu Local Government Council. 600 respondents were proportionally and randomly selected as sample size for the study. General objective was formulated from which five specific objectives were formulated. Among these – is to compare swine prolificacy over the prolificacy of other domestic livestock. Five research questions were formulated to guide this study, among these is – what importance has the prolificacy of swine over other domestic livestocks like goats, sheep, horse and cattle? Five null hypotheses were formulated for the study among these is – there is no significant relationship between the prolificacy of swine over the prolificacy of other domestic livestock in Imo State. Pilot study was conducted at Umuagwo community using 20 respondents that reared domestic livestocks. This area was not part of the study location. Questionnaires were used as a medium for data collection. One sample T-test was used to test five null hypotheses at 0.05 level of significance and all the null hypotheses were rejected meaning that there were significant differences between pig productions over the production of other domestic livestock. The analysis yielded the following results: swine production was accepted to be more prolific than other domestic livestocks like goats, sheep, horse and cattle. It was also agreed that swine were more adapted to wide varieties of feeds which made them to grow more quickly than other domestic livestocks. It was concluded that swine production was more economically important than the rearing of other domestic livestock. It was recommended that National Poverty Eradication Programme (NAPEP) in Imo State should enlighten the respondents on the economic importance of swine production over the rearing of other domestic livestock. Piglets should be made available to farmers who wish to embark on swine production at affordable price by Anambra – Imo River Basin Development Authority (AMRBDA).Keywords: Swine Production, Domestic Livestock, Mbaitolu Local Government Council.

Spatio-Temporal Dynamics of Sediment yield across the Imo River Basin South- East Nigeria

Soil and water are the two main natural resources that sustain human existence on earth. Proper monitoring and maintenance of these resources are done on basin level. The IRB drains an area of 7,951.03 km2. The basin has a mean annual discharge of 120m3/sec and generates significant surface runoff and sediment. The study aim was to evaluate the sediment yield across IRB using the Soil and Water Assessment Tool (SWAT) model. SWAT is a watershed-based, semi-distributed hydrologic model for simulating hydrological processes at different spatial scales. The model utilized digital elevation model DEM to extract the river network, basin delineation, and sub-basin division. The sub-basins were further divided into hydrological response unit HRU at a threshold of 5% slope, 5% the land use and 5% soil. Harmonized soil data and two land-use data of 1995 and 2010 were used to simulate the sediment yield across IRB. The study result shows an increase in sediment yield of 0.73 t/ha from1995 to 2010. Sub-basin 10 has the highest sediment yield during the two periods; September and October are the months with the highest sediment yield.

Hydrogeophysical studies for the determination of aquifer hydraulic characteristics and evaluation of groundwater potential: A case study of some selected parts of Imo River Basin, South Eastern Niger

Hydrogeophysical studies for the determination of aquifer hydraulic characteristics and evaluation of groundwater potential: A case study of some selected parts of Imo River Basin, South Eastern Niger

Simulation modeling using Markovian Decision theory in co-managing the competitive Anambra and Imo river basin

Abstract This work for purposes of efficiency aims at funding Anambra and Imo River Basin Development Authorities (RBDAS), namely RBDA I and RBDA 2, according to their net returns achieved on investment, since they operate within the same region of influence and are managed by a single board of directors. The RBDAS are competitively embarking on irrigated agriculture, water supply, hydroelectric power generation, flood control, drainage, navigation, recreation/tourism and erosion control. There is an expansion fund of ₦ 782.76 billion for full capacity utilization of the basin's assets involving 25 rivers in the South East Geopolitical region. The problem facing each of the RBDA is their strategy or optimal policy to maximize its net return per unit of investment on each of the developmental projects. On the other hand, the problem facing the management board is the ratio in which to share the funds available for expansion as to allow each of the RBDA to perform at an optimum level. Methodology involves methods and experiments. Data were collected from ABDAS, Ministries and Parastatal. When RBDA1 and RBDA 2 invest under the most unfavorable competition, it can assure itself of a net return ratio of 460/1000 respectively. Consequently, the management board will share the new fund (₦ 782.76 billion) available for expansion so as to allow each RBDA to perform at an optimum level according to the said ratio, which is the value of the Markovian Decision rule to ensure optimum efficiency. That is RBDA 1 gets ₦ 246.62 billion and RBDA 2 gets ₦ 536.14 billion.

Low prevalence of epilepsy and onchocerciasis after more than 20\u2009years of ivermectin treatment in the Imo River Basin in Nigeria

BackgroundHigh epilepsy prevalence and incidence have been reported in areas with high onchocerciasis transmission. Recent findings suggest that proper community-directed treatment with ivermectin (CDTI) is potentially able to prevent onchocerciasis-associated epilepsy (OAE). We assessed the epilepsy prevalence and onchocerciasis transmission in two Nigerian villages following more than 20 years of CDTI.MethodsA cross-sectional door-to-door survey was performed in two villages in the Imo River Basin reported to be mesoendomic for onchocerciasis (Umuoparaodu and Umuezeala). Individuals were screened for epilepsy using a validated 5-item questionnaire. Persons suspected to have epilepsy were examined by a neurologist or a physician with training in epilepsy for confirmation. Onchocerciasis was investigated via skin snip microscopy and rapid diagnostic tests for Ov16 antibodies. Results were compared with previous findings from the Imo river basin.ResultsA total of 843 individuals from 257 households in the two villages were encountered. We detected four persons with epilepsy (PWE) giving a crude epilepsy prevalence of 0.5%. This finding differs from observations reported 14 years ago which showed an epilepsy prevalence of 2.8% in the neighbouring village of Umulolo (P = 0.0001), and 1.2% from 13 villages in the Imo river basin (P = 0.07). The seroprevalence of Ov16 antibodies was found to be 0%. Only 4.6% of skin snips were positive compared to 26.8% in previous surveys (P < 0.0001). Ivermectin mass distribution coverage in the study sites in 2017 was 79.7%.ConclusionsA low epilepsy and onchocerciasis prevalence was observed following more than 20 years of CDTI in the Imo River Basin. Absence of Ov16 antibodies indicates minimal transmission of onchocerciasis. These results contrast with observations from areas of high onchocerciasis transmission, where epilepsy prevalence and incidence remain high. Findings from this study suggest that sustained efforts could eventually achieve elimination of onchocerciasis in these villages.

Regional Hydro-geophysical Study of the Groundwater potentials of the Imo River Basin Southeastern Nigeria using Surficial Resistivity Data

Regional Hydro-geophysical Study of the Groundwater potentials of the Imo River Basin Southeastern Nigeria using Surficial Resistivity Data

Effect of Commercial Sand Mining on Water Quality Parameters of Nworie River In Owerri, Nigeria.

Nworie River, in the Imo River basin of Nigeria, roughly bisects Owerri municipality which hosts the administrative capital of Imo State of Nigeria. As a result of this location the river is vulnerable to potentially polluting human activities. A study of the water quality parameters was done in 2008 as a baseline for monitoring future changes in the river. That study recommended professionally supervised dredging to remove surplus silt and organic debris in some sections of the river. What followed in the past few years has been an unsupervised free-for-all commercial sand mining that has conspicuously degraded the physical characteristics of the river. The aim of this study was to investigate the effect of this sand mining on quality parameters of the river. A total of eleven(11) physico-chemical parameters were investigated. The study showed that major indicators of organic pollution like high ammonia-nitrogen, low dissolved oxygen and high carbon dioxide concentrations still persist and, in some cases, have become worse since the sand mining activities. The study recommends an immediate stop to the sand mining followed by a professionally supervised dredging to restore the physical and biological characteristics of the river.