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- ItemComprehensive evaluation of satellite precipitation products over sparsely gauged river basin in Nigeria(Springer Nature, 2025-02-20) Habeeb Oladimeji Ganiyu, Faridah Othman, Wan Zurina Wan Jaafar and Cia Yik Ng1The study evaluated GPM-IMERG07, CHIRPS2.0, CPC-CMORPH, and PERSIANN-CDR against ground observations of rainfall for five gauging stations over 10 years (2013–2022) in the Niger Central Hydrological Area, Nigeria. This area is prone to severe annual floods, which lead to devastating downstream effects. The lack of high density and evenly distributed rain gauge stations has hindered effective research on mitigating food impacts, necessitating alternative rainfall data sources. Satellite precipitation products (SPPs) are used globally because of their high temporal and spatial resolution, free accessibility, and extensive coverage. However, these products have inherent biases and require comprehensive evaluation. The study employed scatter plots and descriptive statistics for daily and monthly comparisons. Daily SPPs were further analyzed using categorical statistics and a four-component error decomposition method. The findings revealed a higher correlation and greater errors at the monthly temporal resolution than at the daily resolution. PERSIANN-CDR performed better (daily and monthly) with a slightly higher median correlation (0.33 and 0.86), RMSE (9.66 mm and 57.59 mm), and Bias (-0.13 and 4.02). Furthermore, it demonstrated exceptional rainfall detection probability (POD =85%) and minimal miss bias (MB=119.2 mm/day) compared to other SPPs. Therefore, the high performance of PERSIANN-CDR in most statistical indices validates its suitability for the study area. Nonetheless, SPPs exhibited high bias values above the perfect value of zero (0). Thus, it is recommended that algorithm developers reduce these biases to improve the suitability of SPPs. End users should also consider bias correction or data merging to enhance the accuracy of the hydrological simulations.
- ItemEffects of Watershed Delineation on the Prediction of Water Quality Parameters in Gaa Akanbi Area, Ilorin(Lujosh Ventures Limited in LAUTECH Journal of Civil and Environmental Studies, 2022-03-31) Adeogun, A. G., Ganiyu, H. O., Adetoro, A. E. and Idowu, B. S.Watershed delineation is a required step when conducting any spatially distributed hydrological modelling. The prediction of water quality parameters in a basin entails delineation of watershed into different number of sub-basins. Thus, this research evaluated effects of watershed delineation on the prediction of water quality parameters in Gaa Akanbi area of Ilorin, Kwara state, Nigeria. The objectives are to model and predict water quality parameters in the watershed; delineate the selected watershed in various numbers of sub-basins and study the effects of watershed delineation in the prediction of water quality parameters of the basin. For proper implementation of this study, Geographical Information System (GIS) software, physically based watershed model - Soil and Water Assessment Tool (SWAT) and other data processing software were used. Since the model is physically based, the surface properties (i.e. Digital Elevation Model (DEM), stream network, digital soil map, digital land use and land cover map, climatic and hydrological data) served as input in the model. The model was daily for a period of 30 years (i.e. January 1991 to December, 2020). The results showed that the watershed was successfully delineated to 3,7,11,21,32,53 sub-basins. Also, it was noted that the predicted values of water quality parameters (Nitrate, organic phosphorus and sediment concentration) are directly proportional to increase in the number of sub-basins delineated in the watershed.
- ItemImpact Resistance of Coconut Fibre-Reinforced Concrete(Journal of Engineering Research, 2024-06-20) Samson Olalekan Odeyemi, Abdultawab Shitu, Michael Oluwasegun AdisaConcrete is often subjected to impact loads which reduces its service life. Natural fibres like coconut fibre have certain mechanical and physical properties that can be used to reinforce concrete against such loads. This study used the Charpy impact test to determine the impact resistance of different mix ratios of coconut shell fibre-reinforced concrete. The result revealed that a 3% inclusion of coconut fibre significantly enhanced the material's ability to withstand impact loads. The optimal proportion for maximizing impact resistance was identified as 3%. Concrete samples with a 1:1:2 mix ratio exhibited increased energy absorption capacity, emphasizing the impact of mix proportions on the material resistance to impact.
- ItemQUALITY EVALUATION OF SANDCRETE BLOCKS PRODUCED IN SELECTED LOCAL GOVERNMENT AREAS OF KADUNA STATE, NIGERIA(Nigerian Journal of Technology (NIJOTECH), 2024-12-01) U. N. Wilson, H. I. Aliyu, S. O. Odeyemi, O. Adediji, A. O. Durosinlorun, and P. AbubakarNigeria has witnessed problems in the construction industry such as the collapse of buildings which is a consequence of the use of substandard materials in building construction, poor supervision, negligence to standard code of practice, poor maintenance culture, and faulty design amongst others. Quality assurance and quality control are highly imperative to take cognisance of while examining building companies. This research examined the quality of nine-inch hollow concrete blocks produced using machine moulding in Kaduna Metropolis, which includes Kaduna North, Kaduna South, parts of Igabi, and parts of Chikun Local Government Areas in Kaduna State. The study employed a mixed research design method comprising experimental design and interviews. The result of the laboratory test carried out on the blocks showed the mean compressive strength of the blocks ranges from 0.21N/mm2 to 0.62N/mm2 which does not meet the minimum of 1.6N/mm2 compressive strength provided by the Nigerian Industrial Standard (NIS) 87:2000. The bulk densities of the samples tested range from 1286kg/m3 to 1537kg/m3 and are below the minimum of 1,800kg/m3 provided by NIS 87:2000. The result of the interview conducted across 32 block industries showed a complete ignorance of standards as block industries determine their standard based on market forces. Only 3% of the block industries complied with the mix ratio of 20-25 blocks per one bag of cement, and less than 10% carried out quality assurance checks such as weekly inspection of mould for wear and tear and taking measurements of the dimensions to ensure that it meets the standard. In all, only one of the block industries provided evidence of certification from the Standard Organisation of Nigeria (SON). The study further underscored the urgent need for enforcing industry standards in the production of hollow sandcrete blocks in the Kaduna metropolis.
- ItemDevelopment of Aggregate – Cement Design Curves for the Production of Concrete Mixes for Different Grades of Concrete(Civil Engineering Beyond Limits, 2024-12-14) Uwemedimo Nyong Wilson, Tita Gerald Torbem Mando, Samson Olalekan Odeyemi, Oluwasijibomi Adediji, Joseph Oluwatoyin PeterDeveloping aggregate-cement design curves tailored to different concrete grades using locally sourced materials is critical for the growth of Nigeria's construction industry. Such curves provide a systematic approach for optimizing project-specific concrete mixes, enhancing cost-effectiveness, and ensuring structural reliability. This study focuses on creating these design curves by examining the engineering properties and characteristics of raw materials commonly available in Nigeria. Trial mixes were conducted with varying aggregate-cement ratios, and compressive strength tests were performed to identify the most suitable combinations. Using river sand, single-sized aggregates (10–20 mm), and limestone Portland cement, aggregate-cement curves were developed for concrete grades ranging from 20 MPa to 35 MPa. The COREN/2017/016/RC concrete mix design method was adopted to guide the research process. The study found that a mix of 35% fine aggregate, 65% coarse aggregate, and a water-cement ratio of 0.5 achieved optimal results, providing desired compressive strengths and slump values between 40 mm and 50 mm. These findings establish a framework for producing durable and efficient concrete mixes using locally available materials. This approach supports the need for sustainable construction practices in Nigeria, offering practical solutions for meeting diverse construction demands while ensuring material availability and affordability.