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:2010
卷号:18
出版社:IAEH
摘要:Detailed investigations including resistivity, seismic and magnetic measurements and one borehole was conducted. Horizontal Electrical Profiles (HEP) were also carried out to determine the thickness of the alluvial deposits. The combinations of vertical electrical sounding (VES), horizontal electrical profiling (HEP), and drilling led to the identification of the different groundwater bearing horizons in the area of study. The geo-electrical cross-section indicates that the groundwater occurs in two aquifers. A shallow unconfined aquifer is composed of alluvial deposits at 22 m depth, underlain by a weathered basaltic unit. A deep confined aquifer is found at a depth of about 150 m that is composed of gravelly sandstone. A test borehole penetrated two saturated zones: a shallow alluvial deposit unconfined aquifer at 20 m, and a deep gravelly sandstone confined aquifer associated with faulting at 120 m. The static piezometric surface stabilized at 44 m and the drilling resulted in a productive well. The borehole information agreed well with the yield interpretation. Abundant fresh groundwater was found in the northern part of the study area with the highest yield. Significantly, the majority of the groundwater was found within the deep confined gravelly sandstone aquifer, rather than in the shallow unconfined aquifer. The interface between fresh and saline water was delineated. The groundwater in the southern part was contaminated by saline connate water, therefore for such areas deep boreholes are recommended.