f Non Seismic - Contribution to Groundwater Investigation, Case Studies, UAE and Egypt

These are two case studies of using the non seismic (geoelectrical measurements) to investigate the groundwater in the areas of agricultural activities and irrigation purposes which in turn depend on the groundwater of the quaternary aquifer, which is considered the main source for groundwater in the area, and recommend the proper way for drilling. The Paleochannels at Wadi Murikhat and Wadi Sa'a at Al-Ain of UAE are of important target to be detected through the 2D-electrical tomography Survey. Eleven (2D) profiles along these wadies in the area guided with the available borehole data. The 2-D resistivity tomograms of the eleven profiles indicate remarkably the different hydrostratigraphic units of the quaternary aquifer along the eastern margin of Al Jaww plain. Erosional unconformities at the base of the quaternary alluvium are traced along some of the 2-D profiles. These unconformities represent the paleochannels in the bed rock that were formed in the geological past by the ancient wadies. As well as another case study where, the water differs in its quality along short distances over the area at the Eastern Nile Delta of Egypt. The main goal of this study is to find the probable reasons for these differences in the water quality and recommend the proper way for drilling in the area, to investigate the good quality underground water. Twenty five vertical electrical sounding (VES) were carried out in the area using the Schlumberger's array. The lithological and hydrological data from boreholes were used to relate the interpreted resistivity variations of VES conducted over some of these boreholes. Water samples are collected from the available nine wells to evaluate the hydrological characters as the salinity which is a dominant factor in the study area to control the interpreted resisitvity of the aquifers. The interpretation of these soundings revealed that, the area has been crossed by a buried channel, which is believed to be of the Pleistocene prenile distributaries. The groundwater occurrence could be divided into shallow and deep fresh water aquifers separated by saline water one of marine Miocene sediments. The Miocene sediments affect negatively on the groundwater quality, water wells have to be located along the proposed site of the buried channel and above the highest structures, to avoid the Miocene sediments.