期刊名称:Journal of Environmental Hydrology (ältere Jahrgänge)
印刷版ISSN:1058-3912
电子版ISSN:1996-7918
出版年度:2012
卷号:20
出版社:IAEH
摘要:The dependence on boreholes and hand-dug wells for water is increasing rapidly in Zaria, Nigeria, because of the inability of Water Works Department in the area to meet the water consumption requirement of the people. Almost all the boreholes and wells in the area fail to yield during dry seasons due to drastic reduction in groundwater table. This results in acute water shortage in the area. Virtually all the boreholes are located outside of valleys. Electrical resistivity tomography was conducted in the vicinity of two valleys in the area to delineate their underlying aquifer zones. The data were collected along five profiles laid perpendicular to the valleys� strike. The data were tomographically inverted. Interpreted results show that the resistivity ranges of the bedrocks on either side of each of the valleys differ significantly which suggests sharp differences in the properties of the bedrocks on either side of the valleys. It suggests contacts of different rock blocks at the valleys� floors. The results also suggest that the basement on either side of each of the valleys slopes towards the valleys� floors. The basement underlying the valleys� floors is characterized by fault zones between the different rock blocks that are identified on the tomograms as low resistivity zones flanked by high resistivity zones. The resistivity ranges within the fault zones suggest that they are aquifers. The results generally suggest that the valleys in the Zaria area most likely have tectonic origins with fault zone aquifers. The study infers that aquifers which underlie the valley floors are most likely recharged during all seasons compared to those outside the valleys.