Seismic refraction tomography imaging of high-permeability zones beneath an earthen dam, in Zaria area, Nigeria

Osazuwa, IB; Chinedu, Ani D.

doi:10.1016/j.jappgeo.2008.08.006

Cited by 34 publications

(13 citation statements)

References 18 publications

(22 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These features can be as a result of excessive weathering or fracturing of the bedrock within the area. However it is in good agreement with profile 2 of the seismic refracttion tomography result of Osazuwa and Chinedu [11] where the same feature existed as depression below the 10 m depth of the profile. Profile three (P3) (Figure 4) is shown to be adversely affected by the dryness of the ground, which makes movement of ions within the subsurface difficult.…”

Section: Results and Interpretationsupporting

confidence: 84%

“…This is a probable evidence of permeable zones that conducts seepage and eventual accumulation at that level. This was slightly detected by the seismic refraction investigation in the same profile of Osazuwa and Chinedu [11]. Besides the feature of this diapiric structure, other very high apparent resistivity areas are probably related to natural geologic materials that may be interpreted as dried weathered materials.…”

Section: Results and Interpretationmentioning

confidence: 62%

“…It can also give an idea of the data coverage that can be obtained with different arrays. The nearest available three borehole log data are used as control over the interpretation of the resistivity pseudosections ( Table 1) as done in Osazuwa and Chinedu [11]. It is always necessary to consider further exploratory geophysical results gathered from the surface with borehole log data.…”

Section: Results and Interpretationmentioning

confidence: 99%

“…Benson et al [10] had also applied it successfully to the detection of buried wastes and wastes migrations. On the other hand, Osazuwa and Chinedu [11] had earlier investigated and mapped the high permeability zones beneath the same dam using Seismic Refraction Tomography. Their results showed the existence of depressions and low velocity zones indicating the presence of loose and unconsolidated materials beneath the flanks of the dam.…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, detection and characterization of loose and unconsolidated formations which may be a source of water loss from the dam through seepage, is highly necessary, in order to prevent structural failure of the dam. Most importantly, it is intended to provide complementary information about the subsurface as discussed in Osazuwa and Chinedu [11].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Electrical Resistivity Imaging of Suspected Seepage Channels in an Earthen Dam in Zaria, North-Western Nigeria

Chinedu¹,

Ogah²

2013

OJAppS

View full text Add to dashboard Cite

To determine and map the subsurface conditions of a dam, a 2D electrical resistivity tomography study was carried out within the two flanks of Zaria dam at Shika. This was done to ascertain if the variations in the volume of water content in the dam is due to an anomalous seepage beneath the subsurface or seasonal effects. On the basis of the interpretation of the acquired data, various zones of relatively uniform resistivity values were mapped and identified. The first zone is characterized by moderate resistivity values of 150 -600 ohm-m. It represents unsaturated topsoil with thicknesses varying from 1 -4.5 m. The second (intermediate depth) resistivity zone, with values ranging from 5 -100 ohm-m and thickness varying from 3.5 -10 m, represents a silt clay layer with high moisture content. The third resistivity zone represents fairly weathered granite and is characterized by relatively high resistivity values ranging from 700 -6000 ohm-m. The available borehole log data correlated well with the pseudo-sections in relation to the obtained resistivity values and depth. Zones of relatively low resistivity within the bedrock are interpreted to represent potential seepage pathways. Hence, this geophysical method can be successfully used to delineate and map these seepage pathways within the subsurface of the earth dam.

show abstract

Section: Results and Interpretationsupporting

confidence: 84%

Section: Results and Interpretationmentioning

confidence: 62%

Section: Results and Interpretationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Electrical Resistivity Imaging of Suspected Seepage Channels in an Earthen Dam in Zaria, North-Western Nigeria

Chinedu¹,

Ogah²

2013

OJAppS

View full text Add to dashboard Cite

show abstract

Evidence for extreme variations in the permeability of laterite from a detailed analysis of well behaviour in Nigeria

Bonsor

MacDonald

Davies

2013

Hydrological Processes

View full text Add to dashboard Cite

Abstract:Laterite soils are widespread in tropical Africa and have a large impact on the hydrology of the areas they cover. The permeability of laterite helps determine the partitioning of runoff and interflow and regulates groundwater recharge to underlying bedrock. Groundwater within laterite also forms a widespread source of drinking water, typically from unimproved hang-dugwells. Despite its importance, there is little published information on laterite aquifer properties. In this study, data from a 6 m deep well in Nigeria have been analysed to characterise the hydraulic conductivity of the laterite from repeated pumping tests. Transmissivity measurements from 40 tests spread out across a hydrological year varied from 0.1 to 1000 m 2 /d. Further interpretation of the data demonstrate a strong non-linear decrease in horizontal hydraulic conductivity with depth, characterised by an upper horizon of extreme permeability (400 m/d), and a much lower permeability profile beneath (<0.1 m/d). These data are substantiated with observations from other wells throughout the area. This non-linear permeability structure has several implications: the upper laterite can facilitate rapid lateral throughflow in the wet season, enabling contaminants to be transported significant distances (up to 1 km); natural groundwater levels are restricted to a narrow range for much of the year; and, in the dry season, the lower permeability of the deeper laterite restricts the amount of water which can be abstracted from shallow wells, leading to well failure. The work highlights the need for a wider study to better understand laterite soils and the role they play in regional hydrology.

show abstract

Application of Seismic Refraction Tomography to Map Bedrock: A Case Study from Al-Amrat, Oman

Farfour

Al-Hosni

2019

On Significant Applications of Geophysical Methods

View full text Add to dashboard Cite

Seismic refraction tomography imaging of high-permeability zones beneath an earthen dam, in Zaria area, Nigeria

Cited by 34 publications

References 18 publications

Electrical Resistivity Imaging of Suspected Seepage Channels in an Earthen Dam in Zaria, North-Western Nigeria

Electrical Resistivity Imaging of Suspected Seepage Channels in an Earthen Dam in Zaria, North-Western Nigeria

Evidence for extreme variations in the permeability of laterite from a detailed analysis of well behaviour in Nigeria

Application of Seismic Refraction Tomography to Map Bedrock: A Case Study from Al-Amrat, Oman

Contact Info

Product

Resources

About