Bedrock topography from magnetic anomalie—An aid for groundwater exploration in hard‐rock terrains

Geophysics ◽  
1991 ◽  
Vol 56 (7) ◽  
pp. 1051-1054 ◽  
Author(s):  
H. V. Ram Babu ◽  
N. Kameswara Rao ◽  
V. Vijay Kumar
Keyword(s):  
Hard Rock ◽  
Unconfined Aquifer ◽  
Groundwater Potential ◽  
Groundwater Exploration ◽  
Magnetic Method ◽  
Magnetic Response ◽  
Basement Rock ◽  
Bedrock Topography ◽  
Weathered Layer

The role of the magnetic method in groundwater exploration is to locate structures such as dikes, faults, fractures, etc., that control the accumulation and movement of groundwater. In hard‐rock terrains, the thickness of the weathered layer is an important parameter that determines the quantity of groundwater accumulated in the unconfined aquifer above the basement. The basement rock, in the process of weathering, loses its magnetic properties and becomes much less magnetic. Therefore, the magnetic response is mostly due to the unweathered hard basement rock, and the depths of magnetic sources obtained from the analysis give us the top of the basement. Information about the thickness of the weathered layer would help in assessing the groundwater potential of the region.

scholarly journals Use of Earth Observation Images and GIS Techniques for Groundwater Exploration in Hard Rock Terrain

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
P. MOHANA ◽  
S Muthusamy
Keyword(s):  
Remote Sensing ◽  
Water Resources ◽  
Ground Water ◽  
Hard Rock ◽  
Groundwater Potential ◽  
Groundwater Exploration ◽  
Scientific Data ◽  
Srtm Dem ◽  
Regional Patterns ◽  
Hard Rock Terrain

Prolonged drought and improper maintenance of water resources increased the demands on ground-water supplies resulting are focuses for the need to evaluate ground-water resources in the hard rock terrain. In recent years, Remote-Sensing methods have been increasingly recognized as a means of obtaining crucial geo-scientific data for both regional and site-specific investigations. This work aims to develop and apply integrated methods combining the information obtained by geo-hydrological field mapping and those obtained by analyzing multi-source remotely sensed data in a GIS environment for better understanding the Groundwater condition in hard rock terrain. In this study, digitally enhanced Landsat ETM+ data was used to extract information on geology, geomorphology. Hill-Shading techniques are applied to SRTM DEM data to enhance terrain perspective views and to extract Geomorphological features and morphologically defined structures through the means of lineament analysis. A combination of Spectral information from Landsat ETM+ data plus spatial information from SRTM-DEM data is used to address the groundwater potential of alluvium, colluvium and fractured crystalline rocks in study area. The spatial distribution of groundwater potential zones shows regional patterns related to lithologies, lineaments, drainage systems and landforms. High yielding wells and springs are often related to large lineaments and corresponding structural features such as dykes. The results demonstrate that the integration of remote sensing, GIS, traditional fieldwork and models provide a powerful tool in the assessment and management of water resources and development of groundwater exploration plans.

scholarly journals Groundwater Potential Assessment Using 2-D Resistivity Method In Kluang, Johor (Malaysia)

Warta Geologi ◽  
2020 ◽  
Vol 46 (3) ◽  
pp. 220-224
Author(s):  
Nazrin Rahman ◽  
◽  
Edy Tonnizam Mohamad ◽  
Rosli Saad ◽  
◽  
...  
Keyword(s):  
Surface Waters ◽  
Hard Rock ◽  
Water Source ◽  
Unconfined Aquifer ◽  
Groundwater Potential ◽  
Suitable Alternative ◽  
Resistivity Method ◽  
Hard Rock Aquifers ◽  
Increasing Demand ◽  
Groundwater Source

Sources of clean water are decreasing due to rapid usage, contaminated surface waters, pollution and dry season. The dependence on the existing water source is not enough to fulfil the increasing demand of population in Malaysia. In order to overcome the problem, groundwater source is the most suitable alternative. 2-D resistivity method was carried out in a granitic area of Kluang, Johor to delineate and locate groundwater resource. 5 survey lines were conducted by using ABEM SAS4000 terrameter and electrode selector which were connected to 41 electrodes through lund cables. Pole-dipole array was chosen in this study for deeper penetration. Collected data were processed by using RES2DINV software to produce inversion model which was then exported to Surfer8 software for visualisation and interpretation. The result shows that most of the study area consist of granite with different level of fracturing. Unconfined aquifer was found at depths of 0 to 50 m. Confined aquifers can be seen at two different zones. They exhibit same properties at three parallel lines, R1-R3 and show continuity between them. It is predicted that the aquifers flow in the southwest to northeast direction. The hard rock aquifers are highly recommended to be drilled as they contain a large amount of fresh water for further usage.

scholarly journals Investigation of groundwater potential using integrated geophysical methods in Moloko-Asipa, Ogun State, Nigeria

2021 ◽  
Vol 11 (4) ◽  
Author(s):  
A. A. Alabi ◽  
S. A. Ganiyu ◽  
O. A. Idowu ◽  
A. F. Ogabi ◽  
O. I. Popoola
Keyword(s):  
Geophysical Methods ◽  
Low Frequency ◽  
Sampling Interval ◽  
Groundwater Potential ◽  
Groundwater Exploration ◽  
Protective Capacity ◽  
Southwestern Nigeria ◽  
Industrial Growth ◽  
Geoelectric Section ◽  
Weathered Layer

AbstractWater is essential for livelihood, development, and industrial growth. Its exploration in sufficient quantity is required where it does not freely occur on the surface. This research was aimed to delineate aquifer regions and provide information on the subsurface lithology of Moloko-Asipa Southwestern Nigeria. A combination of eight traverses investigated with very low frequency electromagnetic (VLF-EM) method at 5 m constant sampling interval and ten vertical electrical sounding (VES) were carried out in the survey. Measurements from the VLF-EM survey were processed with Karous and Hjelt filtering to give the resistivity contrast across the selected profiles. The VES data processing involved an automatic approximation of the initial resistivity and thickness of the geoelectric layers with IPI2Win and further filtering by WinResist iteration. Estimation of Dar-Zarrouk parameters was also employed to investigate the aquifer protective capacity of the area. The processed VLF-EM results showed the geology of the area to an average depth of 25 m. The geoelectric section of the VES data revealed minimum of 3 layers from sandy top soil to weathered layer and fresh basement with an average resistivity values of 1,816, 926 and 17,503 Ωm, respectively. The integration of VLF-EM and VES in the investigation revealed that the potential for groundwater exploration in the study area is poor due to the thin nature of the weathered layer and its shallow depth to basement. The aquifer protective capacity of the area was likewise inferred to be poor.

scholarly journals Use of earth observation images and GIS techniques for groundwater exploration in hard rock terrain

2021 ◽  
Vol 4 (2) ◽  
Author(s):  
P. MOHANA ◽  
S. Muthusamy
Keyword(s):  
Remote Sensing ◽  
Water Resources ◽  
Ground Water ◽  
Hard Rock ◽  
Groundwater Potential ◽  
Groundwater Exploration ◽  
Scientific Data ◽  
Srtm Dem ◽  
Regional Patterns ◽  
Hard Rock Terrain

Prolonged drought and improper maintenance of water resources increased the demands on ground-water supplies resulting are focuses for the need to evaluate ground-water resources in the hard rock terrain. In recent years, Remote-Sensing methods have been increasingly recognized as a means of obtaining crucial geo-scientific data for both regional and site-specific investigations. This work aims to develop and apply integrated methods combining the information obtained by geo-hydrological field mapping and those obtained by analyzing multi-source remotely sensed data in a GIS environment for better understanding the Groundwater condition in hard rock terrain. In this study, digitally enhanced Landsat ETM+ data was used to extract information on geology, geomorphology. Hill-Shading techniques are applied to SRTM DEM data to enhance terrain perspective views and to extract Geomorphological features and morphologically defined structures through the means of lineament analysis. A combination of Spectral information from Landsat ETM+ data plus spatial information from SRTM-DEM data is used to address the groundwater potential of alluvium, colluvium and fractured crystalline rocks in study area. The spatial distribution of groundwater potential zones shows regional patterns related to lithologies, lineaments, drainage systems and landforms. High yielding wells and springs are often related to large lineaments and corresponding structural features such as dykes. The results demonstrate that the integration of remote sensing, GIS, traditional fieldwork and models provide a powerful tool in the assessment and management of water resources and development of groundwater exploration plans.

Assessment and Modeling of Groundwater Potential Zones by using Geospatial and Decision-making approaches: A case study in Anantapur district, Andhra Pradesh, India

2021 ◽  
Vol 5 (1) ◽  
pp. 34-44
Author(s):  
B. Pradeep Kumar ◽  
K. Raghu Babu ◽  
M. Rajasekhar ◽  
M. Ramachandra
Keyword(s):  
Andhra Pradesh ◽  
Primary Source ◽  
Drainage Density ◽  
Groundwater Potential ◽  
Groundwater Exploration ◽  
Groundwater Potential Zone ◽  
Potential Zone ◽  
Groundwater Potential Zones ◽  
Thematic Layers ◽  
Total Study Area

Freshwater scarcity is a major issue in Rayalaseema region in Andhra Pradesh (India). Groundwater is the primary source of drinking and irrigation water in Anantapur district, Andhra Pradesh, India. Therefore, it is important to identify areas having groundwater potential; however, the current methods of groundwater exploration consume a lot of time and money. Analytic Hierarchy Process (AHP)-based spatial model is used to identify groundwater potential zones in Anantapur using remote sensing and GIS-based decision support system. Thematic layers considered in this study were geology, geomorphology, soils, land use land cover (LULC), lineament density (LD), drainage density (DD), slope, and rainfall. According to Saaty’s AHP, all these themes and individual features were weighted according to their relative importance in groundwater occurrence. Thematic layers were finally combined using ArcGIS to prepare a groundwater potential zone map. The high weighted value area was considered a groundwater prospecting region. Accordingly, the GWPZ map was classified into four categories: very good, good, moderate, and poor. The very good GWPZ area is 77.37 km2 (24.93%) of the total study area. The northeastern and southeastern sections of the study area, as well as some medium patches in the center and western regions, are covered by moderate GWPZs, which cover an area of 53.07 km2 (17.10%). However, the GWP in the study area’s central, southwestern, and northern portions is poor, encompassing an area of approximately 79.31 km2 (25.56%). Finally, RS and GIS techniques are highly effective and useful for identifying GWPZs.

Role of the bedrock topography in the Quaternary filling of a giant estuarine basin: the Lower St. Lawrence Estuary, Eastern Canada

2010 ◽  
Author(s):  
Mathieu J. Duchesne ◽  
Nicolas Pinet ◽  
Karine Bédard ◽  
Guillaume St-Onge ◽  
Patrick Lajeunesse ◽  
...  
Keyword(s):  
Eastern Canada ◽  
Lawrence Estuary ◽  
Bedrock Topography ◽  
St Lawrence Estuary
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