Spatial and Temporal Variation of Hydrological and Geometrical Parameters Across River Oyan, Ogun State, South Western Nigeria
Kumolu Olumide Ayodeji1, Adegbola Adedayo Ayodele2, Olaniyan Olatunji Sunday3
1Engr. Kumolu Olumide Ayodeji, Department of Civil Engineering, Ladoke Akintola University of Technology, Ogbomoso, Oyo, Nigeria.
2Engr. Prof. Adedayo Ayodele Adegbola, Department of Civil Engineering, Ladoke Akintola University of Technology, Ogbomoso, Oyo, Nigeria.
3Olaniyan Olatunji Sunday, Department of Civil Engineering, Ladoke Akintola University of Technology, Ogbomoso, Oyo, Nigeria.
Manuscript received on 28 September 2024 | First Revised Manuscript received on 08 October 2024 | Second Revised Manuscript received on 09 December 2024 | Manuscript Accepted on 15 February 2025 | Manuscript published on 28 February 2025 | PP: 1-5 | Volume-14 Issue-3, February 2025 | Retrieval Number: 100.1/ijeat.B455914021224 | DOI: 10.35940/ijeat.B4559.14030225
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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Abstract: Channel erosion and sedimentation are major environmental threats to the sustainability and productive capacity of surface water. Sedimentation poses a significant threat to dam functionality, affecting water storage capacity, structural integrity, and downstream ecosystems. The River Oyan has records of yearly flooding, and the Oyan Dam has drastically reduced its reservoir capacity due to siltation. There was a paucity of information about erosion and sedimentation studies along the river. Objectives: This study aimed to analyse the spatial and temporal variation of hydrological and geometrical parameters on River Oyan as input variables for sediment modelling across the river. Method: Twenty-two (22) years of hydrological and rainfall records were obtained from the Ogun-Osun River Basin Development Authority. Hydrological parameters (flow velocity, discharge), geometrical parameters(breadth, depth), and physico-chemical properties of water samples were measured at six sampling points along the river from April 2021 to March 2024. The physico-chemical properties measured include turbidity, Total Suspended Solids (TSS), pH, Electrical Conductivity (EC), Total Dissolved Solids (TDS), Dissolved Oxygen (DO), and hardness. Descriptive statistics and ttests were used to establish the variation in hydrological and geometrical parameters at a 0.05 significance level. Findings: During the wet season, water samples from River Oyan exhibited turbidity levels ranging from 84.0 to 88.5 mg/L, compared to 8.5 to 16.0 mg/L in the dry season. The Total Suspended Solid (TSS) was higher in the wet season (126-129 mg/L) than in the dry season (83- 86 mg/L). Conversely, temperature and Total Dissolved Solids (TDS) were lower in the wet season. The pH levels of water samples S4, S5, and S6 increased from 7 to 9, 7 to 9, and 8 to 10, respectively, from the wet to the dry season, while that of S3 decreased from 9 to 8. Dissolved Oxygen (DO) ranged from 8.9 to 12.0 mg/L in the wet season and 9.6 to 11.7 mg/L in the dry season. Sampling points’ breadth and depth were greater in the wet season, as were the velocity and discharge. The Cumulative Peak Rainfall was 512 mm, and the runoff ranged from 202.3 to 512 mm. The ttest statistic reveals that the True Value (TV) of all parameters was greater than the Critical Value (CV) of 2.571 at the 95% confidence level (α = 0.05). There is temporal and spatial variation in the hydrological and geometrical parameters along River Oyan. Hydrological and geometrical measurements along the river can ensure the development of a reliable sediment transport model. There is a paucity of information on sediment transport studies on the River Oyan. Novelty: This study is one of the few to examine sedimentation in River Oyan and will serve as a baseline for future research in this domain.
Keywords: Spatial, Temporal, Physico Chemical, Ogun-Osun, River Oyan.
Scope of the Article: Environmental Engineering