<abstract xmlns="http://www.w3.org/1999/xhtml"><p> Studies of structural and hydrogeomorphological units (HGU) that are indicators of groundwater occurrence were carried out across an area extent of more than 700 km<sup>2</sup> within the hard rock terrain of southwestern Nigeria. These studies integrated geological remote sensing techniques (RST) and geographical information system (GIS) methods to generate thematic maps that included elevation, drainage, lineaments and vegetation index for characterising the attributes of groundwater occurrence across the area. The results revealed that the lineament system is mainly rectilinear with major trends of NNW-SSE and NE-SW on the gneiss, NW-SE and NE-SW on porphyritic granite and NNE-SSW, NW-SE and E-W on migmatite. The discharge zones in the area are the lowland terrains underlain by gneiss and amphibolite. Similarly, variably directional discontinuities that are related to rock contacts are equally laden with groundwater. Conversely, the recharge areas are the high-lying terrains characterised by higher fracture density and underlain by porphyritic granite and migmatite. Additionally, there are evidences of groundwater seepage along the major river channels. Therefore, besides the rock structures, landform is another crucial factor that guides groundwater distribution in the study area.</p></abstract>

Studies of structural and hydrogeomorphological units (HGU) that are indicators of groundwater occurrence were carried out across an area extent of more than 700 km2 within the hard rock terrain of southwestern Nigeria. These studies integrated geological remote sensing techniques (RST) and geographical information system (GIS) methods to generate thematic maps that included elevation, drainage, lineaments and vegetation index for characterising the attributes of groundwater occurrence across the area. The results revealed that the lineament system is mainly rectilinear with major trends of NNW-SSE and NE-SW on the gneiss, NW-SE and NE-SW on porphyritic granite and NNE-SSW, NW-SE and E-W on migmatite. The discharge zones in the area are the lowland terrains underlain by gneiss and amphibolite. Similarly, variably directional discontinuities that are related to rock contacts are equally laden with groundwater. Conversely, the recharge areas are the high-lying terrains characterised by higher fracture density and underlain by porphyritic granite and migmatite. Additionally, there are evidences of groundwater seepage along the major river channels. Therefore, besides the rock structures, landform is another crucial factor that guides groundwater distribution in the study area.

Groundwater Occurrence from Hydrogeomorphological Study of Hard Rock Terrain of Part of Southwestern Nigeria

Materials and Geoenvironment

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Studies of structural and hydrogeomorphological units (HGU) that are indicators of groundwater occurrence were carried out across an area extent of more than...

Groundwater Occurrence from Hydrogeomorphological Study of Hard Rock Terrain of Part of Southwestern Nigeria

Published Online: Dec 06, 2018

Page range: 131 - 143

Received: Sep 05, 2017

Accepted: Jan 03, 2018

DOI: https://doi.org/10.2478/rmzmag-2018-0011

Keywords
Hard rock, structures, hydrogeomorphological units, topography, groundwater occurrence

© 2018 Akanbi Olanrewaju Akinfemiwa, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Groundwater Occurrence from Hydrogeomorphological Study of Hard Rock Terrain of Part of Southwestern Nigeria

Published Online: Dec 06, 2018

Page range: 131 - 143

Received: Sep 05, 2017

Accepted: Jan 03, 2018

DOI: https://doi.org/10.2478/rmzmag-2018-0011

KeywordsHard rock, structures, hydrogeomorphological units, topography, groundwater occurrence

© 2018 Akanbi Olanrewaju Akinfemiwa, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Keywords
Hard rock, structures, hydrogeomorphological units, topography, groundwater occurrence