scholarly journals Geophysical Assessment of Impact of E-Waste Pollutants on the Subsurface Soil of Alaba International Market Dumpsite in Lagos, Nigeria.

2021 ◽  
Author(s):  
PAUL ADENIRAN AJAKAYE ◽  
Emmanuel Somoye ◽  
Lawal Owolabi
Keyword(s):  
State Government ◽  
Groundwater Resources ◽  
International Market ◽  
Sand Column ◽  
Array Configuration ◽  
Subsurface Soil ◽  
Configuration Data ◽  
Indiscriminate Disposal ◽  
2D Resistivity ◽  
Wenner Array

Abstract Soil degradation forms a part of the significant impacts arising from indiscriminate disposal of e-waste. This study was aimed at assessing the magnitude of legacy contamination by e-waste, particularly, its depth and spread in the subsurface soil of Alaba International Market e-waste dumpsite in Lagos, Nigeria through the analysis of VES and 2D-Wenner array configuration data acquired on the dumpsite. The results of the VES data and 2D resistivity analysis showed that Alaba dumpsite was highly impacted by e-wastes due to the permeable geo-electric characteristics of the lithologic units beneath the dumpsite. The lithogy enables the pollutants to spread laterally and progressively increase in depth through sand column subsurface to more than 30m. It also showed that the contaminated zones are characterised by resistivity values ranging from 5.0 to 8.3 Ω.m. The study site is highly populated with wells and boreholes as the main sources of water for the community, thus the findings from this study could facilitate Lagos State Government decisions on improving protection for groundwater resources around the study area.

scholarly journals The nature and origin of the Galactic center radio arc: a VLA Faraday study

2013 ◽  
Vol 9 (S303) ◽  
pp. 461-463
Author(s):  
Cornelia C. Lang ◽  
James Toomey ◽  
Dominic Ludovici ◽  
Ann Mao ◽  
Mark Morris
Keyword(s):  
Spectral Line ◽  
Angular Resolution ◽  
Galactic Center ◽  
High Angular Resolution ◽  
Array Configuration ◽  
X Band ◽  
Configuration Data

Despite their discovery almost 30 years ago, the origin of the Galactic center nonthermal filaments (NTFs) remains poorly understood. The improved capabilities of the VLA offer a fantastic opportunity to make a multi-frequency, full spectropolarimetric study of the radio arc at high angular resolution. Observations presented here are from DnC and CnB array configuration data taken at S, C and X band (coverage between 2-12 GHz; continuum only). In addition there are also Ka and Q band (continuum and spectral line coverage) observations that are part of the study but not shown in this short proceedings. These data will allow us to make the first high angular resolution Faraday study of the Galactic center radio arc.

scholarly journals Geophysical Assessment of Subsurface Conditions at Proposed Building Sites: Implications for Foundation Failure and Building Collapse

2018 ◽  
Vol 64 (3) ◽  
pp. 8-20
Author(s):  
Stephen Oluwafemi Ariyo ◽  
Julius Ogunmola Fatoba ◽  
Olateju O. Bayewu ◽  
Kamaldeen Olakunle Omosanya ◽  
Muhedeen Ajibola Lawal
Keyword(s):  
Geological Mapping ◽  
Geophysical Investigation ◽  
Building Collapse ◽  
Resistivity Imaging ◽  
Geotechnical Investigations ◽  
Weathered Layer ◽  
Electrical Sounding ◽  
2D Resistivity Imaging ◽  
2D Resistivity ◽  
Wenner Array

Abstract Building collapse has been a recurrent environmental hazard in Nigeria in the last two decades. This is a corollary of inadequate foundation investigation prior to construction, poor government policies, and general lack of awareness on the importance of geophysical and geotechnical investigations. In this study, geological mapping and detailed geophysical investigation using Electrical Resistivity Imaging (ERI) and Vertical Electrical Sounding (VES) were carried out to understand the suitability of proposed building sites at the main campus of the Olabisi Onabanjo University (OOU), Ago-Iwoye, Nigeria for construction. Both Wenner array and dipole-dipole were used for profiling and Schlumberger for sounding. Four transverses and VES were used in each of the three areas investigated. Our results show that the subsurface of the study areas is underlain by Precambrian basement rock of Nigeria. Rocks in the study area include banded gneiss, porphyroblastic gneiss, biotite-hornblende granite and quartzite schist. The sounding stations across the three areas and 2D resistivity imaging revealed three principal geoelectric layers, the topsoil, the weathered layer and the fractured/fresh basement with varied resistivity values for each layers. At the VES stations, the three geoelectric layers have resistivity values of 62 to 1182 Ωm, 3.2 to 1360Ωm and 87 to 4680 Ωm. On the 2D resistivity imaging profiles, the resistivity of the three layers varies from 2 to 1182 Ωm, 30to 1360 Ωm, and 40 to 2904 Ωm for the topsoil, the weathered basement, and fractured/fresh bedrock. Our work demonstrates that some of the proposed sites are structurally incompetent for engineering or foundation purposes. Excavation of the topsoil and reinforcement are required to sustain the proposed structures.

scholarly journals Geophysical Survey on Open Dumping Landfill for Monitoring Spread of Leachate: A Case Study in Pekanbaru, Riau, Indonesia

2020 ◽  
Vol 5 (2) ◽  
pp. 121-126
Author(s):  
Adi Suryadi ◽  
Frezy Ukhuah Islami ◽  
Husnul Kausarian ◽  
Dewandra Bagus Eka Putra
Keyword(s):  
Waste Disposal ◽  
Groundwater Resources ◽  
Preventive Action ◽  
Residential Areas ◽  
Resistivity Model ◽  
High Population Growth ◽  
Open Dumping ◽  
2D Resistivity

Pekanbaru is a city in Indonesia with high population growth. The increasing amount of the population has a parallel relationship with the increasing quantity of waste disposal. This study has been conducted on an open dumping landfill at Pekanbaru that surrounded by residential areas. Waste disposal produces leachate as a threat to surface water and groundwater resources. This study aims to investigate the contamination spread formed by leachate using the geophysical method. Direct Current Resistivity (DCR) has been used to produce 2 D Resistivity subsurface Models. Data acquisition has been done using multi-electrodes (32 electrodes) with spacing 2 m between electrodes. 2D Resistivity model produced, a contaminant from leachate represented by low resistivity value 26.1 - 870 Ωm. The deepest penetration of leachate that detected is around 3 m from the surface. It has been understood that leachate from the landfill of the study area is not contaminated groundwater yet. It confirmed by groundwater analysis at residential around the landfill area. By knowing the spreading of leachate, preventive action can be made to maintain the quality of groundwater resources.

Mapping of groundwater potential using integrated geophysical techniques at forestry research institute of Nigeria, Ibadan, South Western Nigeria

2021 ◽  
Vol 20 (1) ◽  
pp. 125-140
Author(s):  
J.O. Coker ◽  
A.O. Atilade ◽  
A.A. Alabi ◽  
D.S. Ebeniro ◽  
G.O. Layade
Keyword(s):  
Computer Software ◽  
Groundwater Potential ◽  
Survey Techniques ◽  
Geological Features ◽  
Electrical Sounding ◽  
Potable Water Supply ◽  
Integrated Geophysical Survey ◽  
2D Resistivity ◽  
Wenner Array ◽  
Research Institute

Water is an essential commodity for life survival on Earth. Groundwater exists below the surface in the soil pores, fractures within rocks, fissures, and other weak geological features or zones. The aim of this research was to delineate groundwater potential within the Forest Research Institute of Nigeria (FRIN) and hence determining the possible areas suitable for siting borehole for sustainable potable water supply. Four electromagnetic traverses were carried out and ten vertical electrical sounding (VES) points were identified for detailed probing using the Schlumberger configuration. Wenner array survey was also carried out along two traverses. The VES data collected was processed using curve matching and Computer software called Winresist while Wenner array was processed using RES2DINV. The results from the interpretation of the four (4) EM profiles revealed low conductivity zone with a value ranging from 4.6 to 19.7 mS m.-1 The results of VES give a maximum of four subsurface geoelectrical layers with five curve types, which are K, Q, AK, HK, and KH. The weathered basement has a resistivity value ranging from143.8 to 450 Ωm and depth to basement ranging between 13.9 m and 39.4 m. The interpretation of the ten VES points obtained suggested that three VES points (VES 2, 5, and 7) are suitable for borehole drilling. The results of the 2D resistivity value ranges from 17.5 to 747 Ωm with a varying depth between 3.25 and 15.9 m. The results of the integrated geophysical survey techniques have proven to be an effective method for groundwater delineation in the study area. Keywords: Aquifer, Borehole, Electromagnetic, Geoelectric, and Groundwater

scholarly journals Coastal Ground Water Flow and Management: A State-of-the-Art Review

2020 ◽  
Vol 14 ◽  
Keyword(s):  
Water Supply ◽  
Saline Water ◽  
Groundwater Resources ◽  
Industrial Effluents ◽  
Cost Effective ◽  
Fresh Groundwater ◽  
Local Climate ◽  
Indiscriminate Disposal ◽  
Groundwater Reserves ◽  
Anthropogenic Intervention

Seawater intrusion has led to salinization of fresh groundwater reserves in coastal areas worldwide and has forced the closure of water supply wells. There is a paucity of well-documented studies that report on the reversal of SWI after the closure of a well field. Saline water from a storm surge can flow down storm-damaged submerged water supply wells and contaminate boreholes and surrounding aquifers. Water is an invaluable commodity in nature and can be a limiting resource to man and other living beings. Water quality is influenced by both natural and anthropogenic intervention where the former includes local climate, geology etc., and the latter covers the construction of dams and embankments, irrigation practices, indiscriminate disposal of industrial effluents etc. Therefore, it is highly desirable to properly manage groundwater resources for drinking-water supply by controlling saltwater intrusion. A cost effective method Abstraction, Desalinization and Recharge was found to be efficient.

scholarly journals Analysis of Potential Risks Associated with Urban Stormwater Quality for Managed Aquifer Recharge

2019 ◽  
Vol 16 (17) ◽  
pp. 3121 ◽  
Author(s):  
Song ◽  
Du ◽  
Ye
Keyword(s):  
Groundwater Resources ◽  
Oxygen Demand ◽  
Water Shortage ◽  
Managed Aquifer Recharge ◽  
Aquifer Recharge ◽  
High Concentration ◽  
Sand Column ◽  
Sustainable Resources ◽  
Contamination Risk ◽  
Urban Stormwater Quality

Managed aquifer recharge (MAR) can be used to increase storage and availability of groundwater resources, but water resources available for recharge are constrained due to a surface water shortage. Alternative resources, like stormwater, are receiving increasing attention as sustainable resources for reuse in MAR. However, pollutants in stormwater can impact groundwater quality, and cause clogging of the infiltration system. Based on the stormwater data in the literature, the physicochemical stormwater properties of data were analyzed. The results showed that concentrations of pollutants from different underlying surfaces varied widely. The main pollutants of stormwater were as follows: Total suspended particles (TSSs), organic matter represented by the chemical oxygen demand (COD), nutrients (total nitrogen, TN; total phosphorus, TP; and NH3–N), and metals (Zn, Pb, Cu, Cd, Fe, and Mn). Based on the simulation of TOUGHREACT, the contamination risk of pollutants for each type of stormwater was assessed. The risk of contamination was divided into four categories due to the different migration times of ions through the sand column. The iron ion has the highest risk of contamination, followed by Zn and Mn, and the contamination risk of nutrients and other metals (Pb, Cu, and Cd) are relatively low. Besides, the physical, biological, and chemical clogging risk were evaluated. The physical clogging potential of all types of stormwater is very high because of the high concentration of TSS. According to the concentration of TN that can spur the growth of bacteria and algae, the relative risk of biological clogging for stormwater is greenbelt stormwater < road stormwater < roof stormwater. However, only road stormwater has high chemical clogging due to the existence of iron, which can generate precipitation that blocks the pore volume.

scholarly journals Optimizing Groundwater Aquifers Potential in The Development of Irrigation Wells for Agriculture Using Geo-Electrical Method

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Rustadi , O T Purwadi, I G B Darmawan
Keyword(s):  
Groundwater Resources ◽  
Shallow Groundwater ◽  
Vertical Electrical Sounding ◽  
Shallow Aquifer ◽  
Electrical Method ◽  
Groundwater Aquifers ◽  
Groundwater Aquifer ◽  
Bedrock Depth ◽  
Electrical Sounding ◽  
2D Resistivity

The identification of shallow groundwater aquifers is demanded to sustain the balance of utilization in agriculture and anticipate frictions that can occur due to the overlapping usage of groundwater resources. This study is aimed to identify the potential of groundwater resources based on the thickness and depth of the groundwater aquifer. Geoelectric resistivity methods have done with vertical electrical sounding (VES) and horizontal profiling techniques (2D mapping). The VES data acquisition was carried out with a Schlumberger array while 2D mapping by alpha Wenner array. Inversion results of vertical electrical sounding (VES) show that groundwater resistivity values in sedimentary rocks ranged from 1 to 100 ?m and in igneous rocks between 0.5 - 150 ?m. The results of 2D Resistivity Mapping also show that shallow aquifer depth ranged from 1 to 5 m with a thickness ranged from 15 m to more than 70 m. Meanwhile, bedrock depth ranged from 20 to 150 m with a pattern deeper to the west. Furthermore, the potential of groundwater aquifers in the development of irrigation wells for agriculture should be carried out in the western part of the study area.   Keywords: Groundwater, Shallow Aquifer, Rock Resistivity, Irrigation Well, Geo-Electrical Sounding.

AHP and GIS-based Delineation of Groundwater Potential of Papumpare District of Arunachal Pradesh (India)

2021 ◽  
Author(s):  
Ranji Mahato ◽  
Dhoni Bushi ◽  
Gibji Nimasow ◽  
Oyi Dai Nimasow ◽  
Ramesh Chandra Joshi
Keyword(s):  
Surface Water ◽  
State Government ◽  
Groundwater Resources ◽  
Drainage Density ◽  
Groundwater Potential ◽  
Geographical Information ◽  
Sensitivity Analyses ◽  
Arunachal Pradesh ◽  
Topographic Wetness Index ◽  
Precise Knowledge

Abstract Water is crucial to human survival. Studies on surface water are well documented but precise knowledge of groundwater resources is difficult. Thus, accurate knowledge of groundwater resources could meet the necessities of water at present and in the long run. The application of the Analytic Hierarchy Process (AHP) and Geographical Information System (GIS) together with multi-criteria parameters has emerged as an efficient technique for delineation of groundwater potential in recent decades. However, no efforts to delineate the groundwater potential have been attempted in the study area to date. Hence, in this study, the groundwater potential of Papumpare district of Arunachal Pradesh was delineated by combining AHP, GIS, and ten thematic layers (geomorphology, geology, slope, lineament density, drainage density, rainfall, distance from the major river, topographic wetness index, soil texture, and land use/land cover). The results show about 64% of the area under poor groundwater potential. Moderate and good groundwater potential is found in 31% and 5% of the area, respectively. Map-removal and single-parameter sensitivity analyses revealed that the groundwater potential map is most sensitive to the annual average rainfall with a mean variation index of 1.05% and a weight of 19.07%. The flood/alluvial plains, Siwalik formations with sediments, and level to gentle slopes receiving high rainfall show good potential, and the dissected hills/valleys, metamorphic rock assemblages, steep slopes with low rainfall reveals poor groundwater potential. The overall accuracy of 81.25% with a Kappa coefficient of 0.72 explains good agreement between the reference data and the map. The estimated area under good groundwater potential appears too little concerning the increasing population and urbanization. Therefore, the state government in general and the water resources and planning department in particular need to formulate suitable strategies to combat the water scarcity scenario waiting ahead. The study suggests raising the use of surface water from nearby rivers to lessen the pressure on groundwater resources.

scholarly journals Integrated studies to investigate paleochannel aquifer in Dan Chang District, Suphan Buri Province, Western Thailand

2021 ◽  
Vol 2145 (1) ◽  
pp. 012050
Author(s):  
S Muangnoi ◽  
N Chaimanee ◽  
P Pananont
Keyword(s):  
Remote Sensing ◽  
Groundwater Resources ◽  
Shallow Groundwater ◽  
Pilot Project ◽  
Severe Drought ◽  
Deep Groundwater ◽  
Alluvial Deposits ◽  
Groundwater Yield ◽  
Integrated Studies ◽  
2D Resistivity

Abstract Climate change is currently causing droughts in many parts of Thailand, especially in Dan Chang District, Suphan Buri Province where many areas are outside irrigation coverage and deep groundwater explorations are less successful due to groundwater shortages. Therefore, there is a need to explore other shallow groundwater (i.e. less than 15 m deep) resources to relieve the drought problems in the communities. This work uses integrated studies of remote sensing, geology and geophysics to identify the location of a paleochannel that contains shallow groundwater resources in the Nong Makha Mong Subdistrict, Dan Chang District, Suphan Buri Province. Potential sites were selected using preliminary remote sensing analysis along with field surveys. A high-resolution topography map from aerial photos was generated and 2D resistivity imaging surveys were conducted at the selected sites to delineate the location of the paleochannel. The drilled wells prove the success of the integrated study to identify the shallow groundwater in the paleochannel at a depth of 3 to 15 m with a groundwater yield of 4 m3/h. The sediments from the borehole suggest that a combination of alluvial deposits and fluvial sediments. Due to the relative lower cost of drilling shallow wells, this work could be used as a pilot project for local communities to explore shallow groundwater aquifers in paleochannels in areas that face a severe drought crisis and have very little deep groundwater potential.

IDENTIFIKASI POTENSI AKUIFER MATA AIR PANAS DI KELURAHAN KOYA TONDANO UNTUK PARIWISATA MENGGUNAKAN METODE GEOLISTRIK RESISTIVITAS KONFIGURASI DIPOL-DIPOL

PHARMACON ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 920
Author(s):  
Meylva C. Pojoh ◽  
As'ari As'ari ◽  
Ferdy Ferdy
Keyword(s):  
Cross Section ◽  
Hot Springs ◽  
Hot Spring ◽  
Line Length ◽  
Research Purpose ◽  
Configuration Data ◽  
Dipole Configuration ◽  
2D Resistivity

ABSTRACTThis research purpose is to find hot springs aquifer in Koya Village. Measurement in this research is using MAE X612-EM resistivitymeter, with 48 and 32 pieces of electrode, 10 and 5 meter spaces, line length 480m, 240m and 180m, amount of line 5, and using resistivity geoelectrical method dipole-dipole configuration. Data with format DAT processed by notepad and RES2DINV software. The process results is subsurface 2D resistivity cross section that describe the location of hot springs aquifer. The results acquired in this research is hot springs aquifer with resistivity (1.00-6.55) Ωm. Line 1 have 10 locations of hot springs aquifer with depth ≤ 30 m, line 2 have 5 locations of hot springs aquifer with depth ≤ 27 m, line 3 have 9 locations of hot springs aquifer with depth ≤ 40m, line 4 have 1 location of hot spring aquifer with depth ≤ 7m and line 5 have 3 locations of hot springs aquifer with depth ≤ 7m.Keywords         : Hot spring, geoelectric, dipol-dipol. ABSTRAKPenelitian ini bertujuan untuk menemukan lokasi akuifer  mata air panas di Kelurahan Koya. Pengukuran dalam penelitian ini dilakukan dengan menggunakan resistivitymeter MAE-X612-EM, dengan jumlah elektroda yang dipakai 48 dan 32 buah, spasi 10m dan 5m, panjang lintasan 480m, 240m dan 180m, jumlah lintasan 5, dan menggunakan metode geolistrik resistivitas konfigurasi Dipol-dipol. Data dengan format DAT diolah menggunakan  software notepad dan res2dinv. Hasil pengolahan adalah tampang lintang resistivity 2D bawah permukaan yang menggambarkan keberadaan akuifer air panas. Hasil penelitian diperoleh akuifer air panas dengan resistivitas (1,00 – 6,55) Ωm. Lintasan 1 terdapat 10 lokasi akuifer air panas pada kedalaman ≤ 30 m dari permukaan tanah. Lintasan 2 diperoleh 5 lokasi akuifer air panas pada kedalaman ≤ 27 m. Lintasan 3 terdapat 9 lokasi akuifer air panas pada kedalaman ≤ 40 m. Lintasan 4 terdapat 1 lokasi akuifer air panas pada kedalaman ≤ 7 m. Lintasan 5 terdapat 3 lokasi akuifer air panas pada kedalaman ≤ 7 m.Kata kunci      : Air panas, geolistrik, dipol-dipol.

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