Nils Perttu - Academia.edu (original) (raw)

Papers by Nils Perttu

Research paper thumbnail of Combined electrical resistivity tomography and magnetic resonance sounding investigation of the surface-water/groundwater interaction in the Urema Graben, Mozambique

This study focusses on the hydrogeology of Urema Graben, especially possible interactions between... more This study focusses on the hydrogeology of Urema Graben, especially possible interactions between surface water and groundwater around Lake Urema, in Gorongosa National Park (GNP). Lake Urema is the only permanent water source for wildlife inside GNP, and there are concerns that it will disappear due to interferences in surface-water/groundwater interactions as a result of changes in the hydraulic environment. As the lake is the only permanent water source, this would be a disaster for the ecosystem of the park. The sub-surface geology in Urema Graben was investigated by 20 km of electrical resistivity tomography (ERT) and three magnetic resonance sounding (MRS) surveys. The average depth penetration was 60 and 100 m, respectively. The location of the ERT lines was decided based on general rift morphology and therefore orientated perpendicular to Urema Graben, from the transitional areas of the margins of the Barue platform in the west to the Cheringoma plateau escarpments in the ea...

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Research paper thumbnail of Magnetic Resonance Sounding (MRS) in groundwater exploration, with applications in Laos and Sweden

Water is essential for all life on the planet, sustaining and ensuring the earth’s ecosystem. Gro... more Water is essential for all life on the planet, sustaining and ensuring the earth’s ecosystem. Groundwater from a global perspective provides about 50 % of the potable water, 40 % of the industrial ...

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Research paper thumbnail of Estimation of water quality parameters of aquifers in the Vientiane Basin, Laos, using MRS and VES

Estimation of water quality parameters of aquifers in the Vientiane Basin, Laos, using MRS and VES

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Research paper thumbnail of Geophysical investigations to identify groundwater pathways at a small open-pit copper mine reclaimed by backfilling and sealing

Geophysical investigations to identify groundwater pathways at a small open-pit copper mine recla... more Geophysical investigations to identify groundwater pathways at a small open-pit copper mine reclaimed by backfilling and sealing

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Research paper thumbnail of Assessment of hydrogeological and water quality parameters, using MRS and VES in the Vientiane Basin, Laos

Water is essential for all life on the planet, sustaining and ensuring the earth's ecosystem.... more Water is essential for all life on the planet, sustaining and ensuring the earth's ecosystem. Groundwater from a global perspective provides about 50% of the potable water supplies, 40% of the indu ...

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Research paper thumbnail of New geophysical techniques for determining quantity and quality of ground water : an exemple from the Vientiane basin, Laos

The access to clean drinking water in the rural Laos is often restricted. This, together with a p... more The access to clean drinking water in the rural Laos is often restricted. This, together with a poor hygiene, results in serious health problems. In a drilling program for water only around 30% of ...

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Research paper thumbnail of Evaluation of the effectiveness of backfilling and sealing at an open-pit mine using ground penetrating radar and geoelectrical surveys, Kimheden, northern Sweden

Environmental Earth Sciences, 2014

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Research paper thumbnail of Magnetic resonance sounding and radiomagnetotelluric measurements used to characterize a limestone aquifer in Gotland, Sweden

Journal of Hydrology, 2012

ABSTRACT Highlights ► We have tested MRS, RMT, VES and GPR to characterize a limestone aquifer. ►... more ABSTRACT Highlights ► We have tested MRS, RMT, VES and GPR to characterize a limestone aquifer. ► RMT locates the limestone–marl interface and helps to constrain the MRS inversion. ► The T1MRS of MRS suggests the aquifer to be hosted by small fractures and vugs. ► No real correlation between water content and resistivity exist. ► MRS is hence the only method that measure water and hence the extension of the aquifer.

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Research paper thumbnail of Characterization of aquifers in the Vientiane Basin, Laos, using Magnetic Resonance Sounding and Vertical Electrical Sounding

Journal of Applied Geophysics, 2011

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Research paper thumbnail of Determining water quality parameters of aquifers in the Vientiane Basin, Laos, using geophysical and water chemistry data

Near Surface Geophysics, 2011

ABSTRACT The aim of this study is to test the possibility of using magnetic resonance sounding (M... more ABSTRACT The aim of this study is to test the possibility of using magnetic resonance sounding (MRS) and vertical electrical sounding (VES) together with groundwater chemistry data from shallow and deep wells to distinguish freshwater aquifers from salt affected groundwater and moreover determine water quality parameters directly from geophysical data. Three study areas within the Vientiane Basin, including 46 sites and 38 sampled wells, have been chosen for the study. The main water quality parameters affecting the water conductivity in the Vientiane Basin are total dissolved solids (TDS) and hardness and to a minor extent chloride, which all have shown to have fairly high correlation to the electrical conductivity (EC) of groundwater. The resistivity of the aquifers is highly variable but is most often above 4 Omega m, suggesting fresh water. No wells in the investigated areas have water quality parameters exceeding the limit for unacceptable drinking or irrigation water. There is a fairly strong relationship between the conductivity of water from deep wells and the conductivity of the main water bearing layer determined by VES, where the best fit is obtained using: EC[mu S/cm] = 0.4694VES[mu S/cm], R-2=0.69. However, due to equivalence in the VES interpretation and the difficulty to estimate the resistivity contribution from finer sediments, the equation may be seen and used as guidance to good water quality only within the Vientiane Basin area or in other areas with similar geology. The MRS results have been used to identify water layers in the VES inversion results to decrease the uncertainty in the interpretation The combination of MRS and VES techniques has been successful in distinguishing high conductive clay and mudstone from water bearing layers and moreover freshwater aquifers from salt affected water. Altogether, this makes MRS and VES very promising tools for guidance of future drilling and water quality estimation.

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Research paper thumbnail of Combined electrical resistivity tomography and magnetic resonance sounding investigation of the surface-water/groundwater interaction in the Urema Graben, Mozambique

This study focusses on the hydrogeology of Urema Graben, especially possible interactions between... more This study focusses on the hydrogeology of Urema Graben, especially possible interactions between surface water and groundwater around Lake Urema, in Gorongosa National Park (GNP). Lake Urema is the only permanent water source for wildlife inside GNP, and there are concerns that it will disappear due to interferences in surface-water/groundwater interactions as a result of changes in the hydraulic environment. As the lake is the only permanent water source, this would be a disaster for the ecosystem of the park. The sub-surface geology in Urema Graben was investigated by 20 km of electrical resistivity tomography (ERT) and three magnetic resonance sounding (MRS) surveys. The average depth penetration was 60 and 100 m, respectively. The location of the ERT lines was decided based on general rift morphology and therefore orientated perpendicular to Urema Graben, from the transitional areas of the margins of the Barue platform in the west to the Cheringoma plateau escarpments in the ea...

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Research paper thumbnail of Magnetic Resonance Sounding (MRS) in groundwater exploration, with applications in Laos and Sweden

Water is essential for all life on the planet, sustaining and ensuring the earth’s ecosystem. Gro... more Water is essential for all life on the planet, sustaining and ensuring the earth’s ecosystem. Groundwater from a global perspective provides about 50 % of the potable water, 40 % of the industrial ...

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Estimation of water quality parameters of aquifers in the Vientiane Basin, Laos, using MRS and VES

Estimation of water quality parameters of aquifers in the Vientiane Basin, Laos, using MRS and VES

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Research paper thumbnail of Geophysical investigations to identify groundwater pathways at a small open-pit copper mine reclaimed by backfilling and sealing

Geophysical investigations to identify groundwater pathways at a small open-pit copper mine recla... more Geophysical investigations to identify groundwater pathways at a small open-pit copper mine reclaimed by backfilling and sealing

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Research paper thumbnail of Assessment of hydrogeological and water quality parameters, using MRS and VES in the Vientiane Basin, Laos

Water is essential for all life on the planet, sustaining and ensuring the earth's ecosystem.... more Water is essential for all life on the planet, sustaining and ensuring the earth's ecosystem. Groundwater from a global perspective provides about 50% of the potable water supplies, 40% of the indu ...

Bookmarks Related papers MentionsView impact

Research paper thumbnail of New geophysical techniques for determining quantity and quality of ground water : an exemple from the Vientiane basin, Laos

The access to clean drinking water in the rural Laos is often restricted. This, together with a p... more The access to clean drinking water in the rural Laos is often restricted. This, together with a poor hygiene, results in serious health problems. In a drilling program for water only around 30% of ...

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Evaluation of the effectiveness of backfilling and sealing at an open-pit mine using ground penetrating radar and geoelectrical surveys, Kimheden, northern Sweden

Environmental Earth Sciences, 2014

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Magnetic resonance sounding and radiomagnetotelluric measurements used to characterize a limestone aquifer in Gotland, Sweden

Journal of Hydrology, 2012

ABSTRACT Highlights ► We have tested MRS, RMT, VES and GPR to characterize a limestone aquifer. ►... more ABSTRACT Highlights ► We have tested MRS, RMT, VES and GPR to characterize a limestone aquifer. ► RMT locates the limestone–marl interface and helps to constrain the MRS inversion. ► The T1MRS of MRS suggests the aquifer to be hosted by small fractures and vugs. ► No real correlation between water content and resistivity exist. ► MRS is hence the only method that measure water and hence the extension of the aquifer.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Characterization of aquifers in the Vientiane Basin, Laos, using Magnetic Resonance Sounding and Vertical Electrical Sounding

Journal of Applied Geophysics, 2011

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Determining water quality parameters of aquifers in the Vientiane Basin, Laos, using geophysical and water chemistry data

Near Surface Geophysics, 2011

ABSTRACT The aim of this study is to test the possibility of using magnetic resonance sounding (M... more ABSTRACT The aim of this study is to test the possibility of using magnetic resonance sounding (MRS) and vertical electrical sounding (VES) together with groundwater chemistry data from shallow and deep wells to distinguish freshwater aquifers from salt affected groundwater and moreover determine water quality parameters directly from geophysical data. Three study areas within the Vientiane Basin, including 46 sites and 38 sampled wells, have been chosen for the study. The main water quality parameters affecting the water conductivity in the Vientiane Basin are total dissolved solids (TDS) and hardness and to a minor extent chloride, which all have shown to have fairly high correlation to the electrical conductivity (EC) of groundwater. The resistivity of the aquifers is highly variable but is most often above 4 Omega m, suggesting fresh water. No wells in the investigated areas have water quality parameters exceeding the limit for unacceptable drinking or irrigation water. There is a fairly strong relationship between the conductivity of water from deep wells and the conductivity of the main water bearing layer determined by VES, where the best fit is obtained using: EC[mu S/cm] = 0.4694VES[mu S/cm], R-2=0.69. However, due to equivalence in the VES interpretation and the difficulty to estimate the resistivity contribution from finer sediments, the equation may be seen and used as guidance to good water quality only within the Vientiane Basin area or in other areas with similar geology. The MRS results have been used to identify water layers in the VES inversion results to decrease the uncertainty in the interpretation The combination of MRS and VES techniques has been successful in distinguishing high conductive clay and mudstone from water bearing layers and moreover freshwater aquifers from salt affected water. Altogether, this makes MRS and VES very promising tools for guidance of future drilling and water quality estimation.

Bookmarks Related papers MentionsView impact