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Journal of Groundwater Science and Engineering 2023年第4期11卷 422-434页

作者： Daniel Nnaemeka Obiora Johnson Cletus Ibuot Department of Physics and Astronomy University of NigeriaNsukkaEnugu State

Flooding occurs when rainfall exceeds the absorption capacity of soil and causes significant environmental *** this study,electrical resistivity techniques were employed to assess the flood susceptibility of the study area by examining variations in electrical *** to flooding,vertical electrical sounding(VES)and electrical Resistivity Tomography(ERT)profiles were conducted to determine the variations in resistivity within subsurface lithologies exposed to the injected *** injected current penetrated the subsurface units characterised by resistivity ranging from 190.5Ω·m to 6,775.7Ω·m,42.3Ω·m to 7,297.4Ω·m,and 320.2Ω·m to 24,433.3Ω·m in the first,second and third layers,*** layers were identified as lateritic topsoil,medium-coarse brownish grained sand,and coarse pebbly blackish sand,*** calculated reflection coefficients between layers 1,2,and 3 reveal alternation in layers with values ranging from−0.04 to 0.66 and 0.36 to 0.95 for and,*** transverse resistivity,longitudinal resistivity and anisotropy ranged from 243.59Ω·m to 24,115.42Ω·m,199.61Ω·m to 14,950.76Ω·m,and 1.02 to *** derived from the ERT profiles reveal variations in resistivity,pinpointing areas of low resistivity which correspond to waterlogged and impermeable *** result of this study underscores the importance of integrated resistivity techniques in the study of floods,as it provides valuable insights into flood behaviour,and subsurface dynamics.

关键词： Anisotropy vertical electrical sounding electrical resistivity tomography Geoelectric layer Permeability

Estimating aquifer transmissivity using Dar-Zarrouk parameters to delineate groundwater potential zones in Alluri Seetharama Raju District,Andhra Pradesh, India

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Journal of Groundwater Science and Engineering 2023年第2期11卷 116-132页

作者： Bakuru Anandagajapathi Raju Palavai Venkateswara Rao Mangalampalli Subrahmanyam Department of Geophysics Colleges of Science&TechnologyAndhra UniversityVisakhapatnam 530003Andhra PradeshIndia

This study aimed to explore groundwater potential zones in the EGMB of Alluri Seetharama Raju district, Andhra Pradesh, India, for drinking and agriculture purposes. To achieve this goal, 72 vertical electrical soundings(VES) were conducted using the Schlumberger electrode configuration. The resistivity sounding data were analyzed to determine the aquifer thickness, basement depth, Dar-Zarrouk parameters,and aquifer transmissivity. Spatial distribution maps were generated for these parameters to understand the subsurface formation. The analysis revealed a linear groundwater potential zone(8.46 km~2) in the eastern part of the study area, extending in the NNE-SSW direction for 9.6 km. Six VES locations(P24, P27, P29,P30, P33, and P38) in this zone exhibit good potential(>30 m aquifer thickness), while the three VES locations(OP19, P5, and P46) in the central region are recommended for drilling bore wells. Additionally,moderate aquifer thickness(20–30 m) are identified in other VES locations(OP14, OP20, P4, P10, P12,P13, P15, P17, P18, P31, P46, and P50) along streams in the western and central part of the area, which can yield reasonable quantities of water. This information is useful for groundwater exploration and watershed management to meet the demands of tribal population in the study area.

关键词： vertical electrical sounding Longitudinal conductance Transverse resistance Coefficient of anisotropy Potential groundwater locations

Geoelectrical Investigation of Groundwater Potentials of Northern Paiko,Niger State,North Central Nigeria

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Journal of Earth Science 2017年第1期28卷 103-112页

作者： Usman D.Alhassan Daniel Nnaemeka Obiora Francisca Nneka Okeke Department of Physics Federal University of Technology Department of Physics and Astronomy University of Nigeria

vertical electrical sounding（VES） was carried out in northern part of Paiko, North Central Nigeria, using Abem terrameter model SAS 4000 to determine the subsurface layer parameters（resistivities, depths and thickness） employed in delineating the groundwater potential of the area. A total of six transverses with ten VES stations along each traverse, at intervals of 50 m were investigated. It has a maximum current electrode separation（AB/2） of 100 m. Three to four distinct geoelectric layers were observed, namely, the top layer, the weathered layer, the fractured/fresh layer, and the fresh basement layer. The observed frequencies in curve types include 21% of H, 4.2% of HA, 2.4% of K, 4.2% of A, 1.67% of KH and 3% of HK. Eight VES stations were delineated as ground water potentials of the area, with third and fourth layer resistivities ranging from 191 to 398 ？·m. Depths range from 13.60 to 36.60 m and thickness varies from 9.23 to 30.51 m. A correlation of the borehole log with the VES lithology is in agreement. Viable boreholes for good portable water should be sited at VES stations J8 and J10 having a fine aquifer at a depth of 36.60 and 17.80 m respectively with thickness of 30.51 and 15.07 m, respectively.

关键词： vertical electrical sounding groundwater potential northern Paiko resistivity aquifer,geoelectric layer Abem terrameter.

electrical Resistivity sounding for Groundwater Investigation around Enugu Metropolis and the Environs, Southeast Nigeria

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International Journal of Geosciences 2022年第1期13卷 54-70页

作者： Claris C. Nwachukwu Charles C. Ugbor Osim Jethro Ogboke Department of Geology University of Nigeria Nsukka Enugu State Nigeria NNPC Lagos Nigeria

This report evaluates the use of electrical method and borehole data to investigate the subsurface to delineate the groundwater potential in Enugu metropolis and the environs, south-eastern Nigeria other than rely only on resistivity method which could lead to interpretation error. Integrating these 2 data sets is key in this study. The study area is located in the Anambra Basin and is underlain by Nkporo/Enugu Shale which is overlain by the Mamu Formation. It is bounded by Latitudes 6°2 0'00"N to 6°30'00"N and Longitudes 7°25'00"E to 7°35'00"E and covers surface area of about 342 m2. Thirty-one vertical electrical soundings (VES) were carried out across the area using the Schlumberger electrode array with current electrode separation from 2 to 500 m to identify the depths and resistivity values of the identified geo-electric layers. Through data analysis using WinResist software, the apparent resistivity, thicknesses and depths and the thicknesses of the aquifers were generated. The resistivity and depths were modelled to generate resistivity map and depth map. The resistivity of

关键词： electrical Method vertical electrical sounding Groundwater Aquifer Apparent Resistivity

Groundwater Potential Mapping in Lapan Gwari Community Using Integrated Remote Sensing and electrical Resistivity soundings

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International Journal of Geosciences 2023年第8期14卷 719-732页

作者： Ayuba Danmangu Mangs Jude Steven Ejepu Charity Chizaram Nkemkah Solomon Nehemiah Yusuf Adamu Keana Sallau Janet Agati Yakubu Yusuf Ibrahim Williams Midala Wakili Department of Geology University of Jos Jos Nigeria Department of Geology School of Physical Sciences Federal University of Technology Minna Nigeria The Carter Centre Jos Nigeria Department of Geology University of Maiduguri Maiduguri Nigeria Department of Geology Modibbo Adama University of Technology Yola Nigeria

This research aims to address the pressing issue of failed and abandoned wells, causing water scarcity in Lapan Gwari Community, through an improved groundwater exploration approach integrating remote sensing and electrical resistivity soundings. The study area, located within the Zungeru Sheet 163 SE, spans Latitudes 9°30'00"N to 9°32'00"N and Longitudes 6°28'00" to 6°30'00". The surface geologic, structural, and hydrogeological mapping provided essential insights into the hydrogeological framework. Leveraging SRTM DEM data, thematic maps were created for geomorphology, slope, land use, lineament density, and drainage density. These datasets were then integrated using ArcGIS to develop a preliminary groundwater potential zones map. Further investigations were conducted using vertical electrical sounding (VES) and electrical Resistivity Imaging (2D VES) surveys at targeted locations identified by the preliminary map. Results show that the study area predominantly consists of crystalline rocks of the Nigerian Basement Complex, primarily comprising schist and granite with minor occurrences of quartz vein intrusions. Surface joint directions indicated a dominant NE-SW trend. The VES data revealed three to four geoelectric layers, encompassing the topsoil (1 to 5 m depth, resistivity: 100 Ωm to 300 Ωm), the weathered layer (in the 3-layer system) or fractured layer (in the 4-layer system), and the fresh basement rock characterized by infinite resistivity. The shallow weathered layers (3 to 30 m thickness) are believed to hold aquiferous potential. Hydrogeological interpretation, facilitated by 2D resistivity models, delineated water horizons trapped within clayey sand and weathered/fractured formations. Notably, the aquifer resistivity range was found to be between 3 - 35 m and 100 - 300 Ωm, signifying a promising aquifer positioned at depths of 40 to 88 m. This aligns with corroborative static water level measurements. Given this, we recommend drilling depths of a mini

关键词： vertical electrical sounding electrical Resistivity Imaging Fractured Aquifer Groundwater Exploration

Dar Zarrouk Parameter as a Tool for Evaluation of Well Locations in Afikpo and Ohaozara, Southeastern Nigeria

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Journal of Water Resource and Protection 2016年第4期8卷 505-521页

作者： Robert Egwu Otu Iduma Tamunoene Kingdom Simeon Abam Etim Daniel Uko Groundscan Services Nig. Ltd. Port Harcourt Nigeria Institute of Geosciences and Space technology Rivers State University of Science and Technology Port Harcourt Nigeria Department of Physics Rivers State University of Science and Technology Port Harcourt Nigeria

The inhabitants of this area depend solely on contact springs as supply source of potable water. However, provision of potable water to meet the needs of the people still remains an unsolved problem. Therefore, this paper attempts to solve this problem by using Dar Zarrouk (D-Z) Parameters;Total Transverse Unit Resistance, T (Ωm2) and Total Longitudinal Unit Conductance, S (Ω-1) to suggest optimal locations for drilling of boreholes in the study area. To attain this purpose, 50 Schlumberger vertical electrical sounding (VES) curves with maximum current electrode spacing of AB/2 = 681 m were interpreted. Thus, the aquifer parameters information estimated from the (VES) curves were used to prepare contour maps of T (Ωm2), S (Ω-1), aquifer thickness h (m), aquifer resistivity ρ (Ωm), and Water Table Depth (WTD). For effective use of these parameters, iso-thickness and iso-resistivity maps were compared with contour map of transverse resistance. The good agreement between these parameters provided the basis for identification of prolific aquiferous zones. It was observed that the Southern part of the study area majorly underlain by the Afikpo Sandstone of Nkporo Formation (Campanian-Maastrichtian), relatively showed higher T (Ωm2), h (m), and ρ (Ωm) values, which implies high yield aquiferous zones. The relatively loose structure of this sandstone unit, coarse grains, and sorting enables it to be porous and permeable. The Northern part of the region which shows low values for T (Ωm2), h (m), and ρ (Ωm) suggests low productivity for the aquiferous zones. The paucity of water in this parts of the study area can be explained to be as a result of the dominant geology. The high S, values at the Uburu and Okposi locations in this region suggests the presence of saline aquifer. This study would be relevant to the development of effective ground water scheme and for future hydrogeological investigations in the ar

关键词： vertical electrical sounding Dar Zarrouk Parameters Nkporo Formation Afikpo Sandstone