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Item Geoelectrical Variations in Residential Area of Ojongbodu, Oyo, Southwestern Nigeria(Nature Environment and Pollution Technology, 2020) Adagunodo, T. A.; Oladejo, O.P.This study is aimed at mapping the geoelectrical variations in the residential area of Ojongbodu, Oyo, Nigeria. Thirty vertical electrical sounding stations were occupying across the study area using PZ-02 Earth resistivity meter. Four subsurface layers involving topsoil, two weathered layers and bedrock were mapped, with clay being the most dominating soil type in the third layer, which is about 3.9 m below the first two layers. The thickness of the third layer itself is about 10.4 m. About 70% of the bedrock is fractured. The thickness of clay in the third layer cum fractured bedrock could aid development of differential settlements in buildings or total collapse of structures within the study area.Item Application of frequency selection and geoelectrical sounding methods for mapping of leachate’s pathways in an active dumpsite(Springer Nature Switzerland, 2023) Adagunodo, Theophilus Aanuoluwa; Ojoawo, Ayobami Ismaila; Anie, Nicholas Oliseloke; Edukugho, Praise OforitsenereContamination of surrounding environments is one of the threats to the proper maintenance of municipal waste sites in developing nations. This study integrates natural electromagnetic (EM) field and geoelectrical sounding methods to assess the leachate’s pathways in the near-surface layers and groundwater system in and around an active dumpsite. Five natural EM traverses were obtained in varying orientations using PQWT-TC 150 model. Fifteen vertical electrical sounding (VES) data points were randomly occupied using SAS 4000 ABEM resistivity meter. The two techniques revealed some intercalations of conductive and resistive media in the study area. The conductive media are composed of mixtures of leachates into clay and groundwater units, thereby creating zones of very low electrical potential differences from the surface to a depth beyond 30 m. A zone of leachate-aquifer’s interphase exists between the third layer and the fourth layer. The directions of the fluid flow are in the S–N and SE–NW trends, which could be linked to the fault towards the northwestern part of the study area. The fluid dynamics, however, justified the reason for the thick conductive materials being mapped at the northwestern and northern parts of the study area.Item Delineation of structural lineaments of Shaki West Southwestern Nigeria using high resolution aeromagnetic data(Nigerian Society of Physics Science, 2025) Adedokun, O. M.; Oladejo, O. P.; Alao, K. N.; Otobrisec, H.; Suleman, K. O.; Adedokun, O.; Sunmonu, L. A.A minor earthquake, known as earth tremor, often occurs in areas prone to seismic activity. However, there is a notable gap in knowledge about earth tremors, with little documentation conducted before 1987, but a series of notable events between 1990 and 2000 prompted researchers to delve deeper into the study of earth tremors in Nigeria. Therefore, this study is aimed at delineating the structural lineaments of Shaki West Southwestern Nigeria using High Resolution Aeromagnetic Data (HRAD) to identify the underlying basement geology and define the structural framework of the study area. The study area’s aeromagnetic data of Shaki (Sheet 199) underwent processing and interpretation using Oasis Montaj software to assess basement configuration and structural integrity. The data were further enhanced using the Total Horizontal Derivative (THDR) in order to determine the orientations of the lineaments in the study area. The orientations of the lineaments obtained from THDR map revealed that the Pan African orogeny constitutes 52%; Kibaran orogeny constitutes 31%, while Liberian orogeny constitutes 17% lineaments in the study area. The upward continuation maps suggest the presence of faults at the depth range of 2.0-2.25 km. The overall depth to magnetic sources of the area is relatively shallow compared to sedimentary basement area. Based on orientation of faults on magnetic fault map obtained from the superposition of the lineaments extracted from THDR map on the geological map of the study area, three distinct set of sinistral /dextral faults were recognized in Shaki west local government area which includes: E-W, NE-SW and NW-SE fault trend. This suggests that NE-SW and NE-SE fault-set could be responsible for the tremor experienced in Shaki west southwestern, Nigeria. It is concluded that the study area is not immune from experiencing occurrences of tremors from time to time.Item Practice and theoretical analysis of ground penetrating radar in voids detection of urban underground pipe-jacking(Elsevier Inc., 2025) Adagunodo, Theophilus Aanuoluwa; Hu, Fengming; Yang, Tianchun; Zhu, Debing; Huang, RuiPipe-jacking construction technology has become more prevalent with the development of urbanization. At the same time, non-destructive detection of the compactness around the pipe-jacking is a necessary step in the pipe jacking engineering. Therefore, the present study intends to explore the non-destructive detection of pipe-jacking quality by using ground penetrating radar. Ground penetrating radar can also be called GPR for short, and it plays an irreplaceable role in our life through its efficient and nondestructive detection function. In the study, void models for plastic jacking pipes, reinforced concrete jacking pipes, and steel jacking pipes were constructed, and forward simulations of ground penetrating radar were conducted using the two-dimensional finite element method to investigate the parameter influences brought about by seasonal changes and the shape of the voids; furthermore, combined with the sewage jacking pipe project in Xiangtan City, Hunan Province, practical detection and experimental research on reinforced concrete jacking pipes and steel jacking pipes are carried out using ground penetrating radar. The research results indicate that ground penetrating radar is feasible for detecting the density conditions around cement jacking pipes, plastic jacking pipes, and reinforced concrete jacking pipes. However, when detecting the void conditions around steel jacking pipes, strong multiple re flections occur between the radar antenna and the pipe wall, making it impossible to achieve the goal of detecting the density behind the jacking pipe. Therefore, future research is needed to develop new methods and technologies for assessing the construction quality of steel jacking pipes.Item Fluoride Concentrations Within the Shallow Aquifers in Iree, Southwest Nigeria(Springer Nature Switzerland, 2024) Adagunodo, Theophilus Aanuoluwa; Adeniji, Adetunji Ayokunnu; Ojoawo, Ayobami Ismaila; Ajao, Adekunle MayowaAssessing the toxic fluoride concentration in groundwater is critical and vital, since its occurrence in the water has been linked to the natural deposition of parent rocks during weathering. Consumption of fluoride in water can cause serious health problems, such as skeletal fluorosis, dental fluorosis, fertility reduction, urinary tract infection and disorder, nervous system damage and so on. The aim of this study is to determine the fluoride contamination level in the shallow aquifers of a crystalline basement system in Iree community, south-west Nigeria. Fifteen near-surface wells were tested for fluoride constituents and the determination of some physical parameters (such as pH and water temperature). Samples were analyzed by colorimetry in order to determine fluoride concentrations. The normality of the data was tested using the Kolmogorov–Smirnov test, while the fluoride constituents in the water samples were compared to the World Health Organization (WHO) threshold. The obtained fluoride contents varied from 0.75 to 1.5 mg.l−1 , the pH varied from 6.89 to 8.07, and the water temperature varied from 26.8 to 30.5 °C. It was revealed that some near-surface wells exceeded the WHO permissible standard of 1.0 mg. l −1 for fluoride constituents in potable water. Based on these results, it could be concluded that a crucial and periodic assessment of the near-surface wells is recommended to keep track of the fluctuations in the fluoride concentrations within the study area. The outcome of this study will serve as baseline guidance for policy-makers as well as the concerned authorities to know the degree of fluoride constituents in their shallow wells and to proffer possible solutions in mitigating these pollution risks as soon as possible.Item Geospatial mapping of radon concentrations and uncertainties in radiological risk assessments using probabilistic modelling: the case of Ibadan(Springer, 2026) Adagunodo, Theophilus Aanuoluwa; Aremu, Abraham Adewale; Adewoye, Abosede Olufunmi; Oladapo, Olukunle Olaonipekun; Orosun, Muyiwa Michael; Ajibade, Oluwadamilola Ayoola; Muzammil, Khursheed; Zahrani, YousefRadon is a primary source of internal radiation exposure, occurring via inhalation and ingestion. This study investigates the distributions and radiological hazards of soil radon and groundwater radon in Ibadan, a major city in Nigeria. Radon concentrations were measured at 41 sites using a RAD7 detection system. The geospatial distribution was mapped using Surfer 10 software, and health risks were assessed via Monte Carlo simulations (MCS). Soil radon concentrations ranged from 1.75 to 47.24 kBq/m3 (mean: 22.30±14.48 kBq/m3 ), while water radon concentrations ranged from 1.12 to 30.48 Bq/L (mean: 14.17±8.80 Bq/L). The average soil radon level falls below the ICRP limit (40 kBq/ m3), but the average water radon exceeded the EPA limit of 11.1 Bq/L. A strong Spearman rank corre lation of 0.96 was observed between the two media. Geospatial analysis identified Class III hotspots (e.g., Pegba and Oranyan) as priority areas for local miti gation. The MCS quantified the probabilistic health burden, revealing a grand excess lifetime cancer risk ranging from 0.007×10⁻(found in the worst-case scenario at Oranyan) with an average mean of 0.605×10⁻3 . Notably, the maximum probable risk in high-exposure hotspots remains below the ICRP reference level of 3.75×10⁻3, suggesting that while the risk is significant, it does not exceed the international threshold for emergency intervention. These findings underscore the necessity of targeted intervention to manage long-term radio logical health implications for the population.Item Simulation of the Telluric Electrical Field Frequency Selection Method and Its Application in Mineral Water Exploration(MDPI, Basel, Switzerland, 2025) Adagunodo, Theophilus Aanuoluwa; Yang, Tianchun; Yang, Zhu; Qin, Qin; Zhu, MaoyueIn practical engineering geophysics, anomalous bodies are typically three-dimensional (3-D) structures, making it inaccurate to represent the subsurface geoelectric model using a two-dimensional (2-D) assumption. Furthermore, the underlying mechanism of the telluric electrical field frequency selection method (TEFSM) remains insufficiently understood. To address these limitations, this study presents a 3-D forward modeling algorithm based on the edge-based finite element method to solve the TEFSM forward problem. This paper also investigates the application of TEFSM in mineral water exploration, striving to minimize the influence of strong electromagnetic interference sources such as high voltage power lines. Specifically, the paper presents the forward theory of TEFSM and analyzes the causes of galvanic distortion, particularly static shift. Numerical simulations examine the response characteristics of anomalous bodies and the influence of galvanic distortion. The results indicate that galvanic distortion enhances shallow local anomalies in the modulus of the electric field while masking deeper targets. In contrast, the phase of the electric field effectively reflects deeper anomalous bodies and is minimally affected by galvanic distortion. Future improvements in frequency selectors may enable reliable phase measurements, thereby enhancing data interpretability. Subsequently, the TEFSM was applied to field data collected during mineral water exploration. The field test results confirm the effectiveness of TEFSM and demonstrate that it is a portable, simple, low-cost, and highly efficient method for groundwater detection.Item Causes and Possible Solutions to Road Failure in Nigeria(Springer Nature Singapore Pte Ltd., 2025) Adagunodo, Theophilus Aanuoluwa; Adeniji, Adetunji Ayokunnu; Okeniyi, Elizabeth ToyinCracks, defects and potholes characterize Nigerian roads. It is difficult to travel a long kilometer without coming across defects on the road, which has resulted in severe challenges and fatal accidents in Nigeria. The individual road has its life expectancy. In most cases, some roads fail before the expected service life. Some failures are noticed immediately after construction, some are observed after flood ing, and some failures are revealed as a result of a poor drainage system, while a few others could serve their purpose and life expectancy as a result of adequate mainte nance. In Nigeria, transportation via road is an inexpensive and efficient means of transportation for the masses as other transport systems are too expensive or not mature for commercial services. In most cases, the presence of unrestrained axle loads on most of the road networks in Nigeria has resulted in a reduction in the life expectancy of these roads. This chapter briefly reviews the causes of road failure in Nigeria and possible solutions.Item Geoelectrical resistivity imaging as a reliable input for building sustainable agroecological models: a case in southwestern Nigeria(Springer, 2025) Oyeyemi, Kehinde D.; Shiv Mangal Gupta2; Prawan Koppula; Kushal Pal Singhing issues such as diminishing soil fertility and insufficient crop yield. Geoelectrical resistivity imaging serves as a valuable tool for constructing enduring agroecological models. This research presents findings of the application of geoelectrical resistivity imaging to evaluate the agricultural soil quality in terms of nutrients, moisture levels, and organic matter content. Five parallel 100-m-length 2D electrical resistivity tomography (ERT) profiles were conducted, with a minimum spacing of 5 m and reaching a maximum depth of six levels (30 m). Additionally, soil parameters and nutrient content of twenty soil samples from the study area were analyzed to assess the soil fertility level for agricultural practice. The results revealed that the subsoil can be categorized into three geoelectrical units based on inverse model resistivity values: water-saturated soils (5–20 Ωm), moist soils (21–80 Ωm), and dry soils (>100 Ωm). The near-surface subsoils up to about 10 m exhibit higher moisture content, indicating potentially enhanced soil fertility due to improved water availability for plant growth and nutrient uptake. Measured soil parameters reveal ranges of organic matter content (41–98%), electrical conductivity (0.15–0.48 dS/m), and pH values (4.11–8.11). Furthermore, the concentrations of microelements within the near-surface subsoils samples were measured, showing ranges of 176–315 ppm for nitrogen, 25.78–99.78 ppm for phosphorus, and 149–605 ppm for potassium. This study highlights the significance and effectiveness of the geoelectrical resistivity method in evaluating soil fertility for precision agriculture purposes. The method strengthens the core of agroecological models by offering vital subsurface and spatial insights. It empowers well-informed decision-making, supports the practice of sustainable land management, and actively fosters the growth of robust agricultural systems.Item Geoelectrical Characterization of Coastal Aquifers in Agbado-Ijaye, Lagos, Southwestern Nigeria; Implications for Groundwater Resources Sustainability(MDPI, Basel, Switzerland, 2023) Oyeyemi, Kehinde D.; Abuka-Joshua, Joyce; Rotimi, Oluwatosin J.; Dieppois, Bastien; Gomo, Modreck; Olaojo, Abayomi A.; Falae, Philips O.; Metwaly, MohamedWater is a natural resource; its availability depends on climatic and geological conditions, and it is invariably controlled by human activities. Agbado-Ijaye lies within a coastal area, where local communities have been facing incessant water shortages, especially during the dry season. This study investigated the groundwater-bearing geological unit(s) using hydrogeophysical techniques in the coastal environment. The electrical resistivity technique, involving vertical electrical sounding (VES) and two-dimensional (2D) electrical resistivity imaging via Wenner array electrode configuration, was used to characterize the geoelectric distribution. Twenty VES stations were investigated and current electrodes (AB/2 m) spacing expanded from 1–200 m; four 2D electrical resistivity imaging traverses having a length of 200 m each and interelectrode spacing of 10 m (level 1) to 60 m (level 6) was adopted. Four geoelectric units were delineated, namely: topsoil (15–251 Ωm), clayey (28–100 Ωm), clayey sand (125–190 Ωm) and sandy (205–876 Ωm) with thicknesses ranging from 0.7–1.3 m, 4.1–19.0 m, 2.6–15.6 m and undefined depth, respectively. The 2D imaging sections also detected similar geoelectric layers, corroborating the VES-derived sections. The inverted sections delineated two different aquifers: the shallower low-yield aquifer comprising sandy clay/clayey sand units with a maximum depth of about 5.5 m. This layer is adjudged to be the continental plain sand of the Benin Formation. The deeper high-yield aquifer with a maximum depth of 30.4 m is a beach sand unit that belongs to the Tertiary Alluvium of the Dahomey Basin. The study showed that hydrogeophysical investigation is vital in exploring, developing, and managing coastal groundwater resources.