Investigation of groundwater flow heterogeneity in fractured aquifers (Case study: Qusiema area, North Sinai)

Fractured aquifer is considered as a main promising aquifer in northeastern boarders of Egypt where the Nubian aquifer is deep. The groundwater exploration and evaluation are the main objectives of the present study. Some localities were carefully selected for applying the geophysical techniques to achieve the goal of the study. Both the Vertical Electrical Sounding (VES) and horizontal profiling techniques of direct current resistivity method were applied. The hydrogeological information were analyzed and evaluated using the available software. The Direct Current (DC)  resistivity method was applied for delineation the variation of apparent resistivity of sedimentary succession that depends on the density of fractures and cavities. The lateral and vertical distribution of resistivity was mapped to delineate the lateral extension of fractures. Calibration of the resistivity model with the lithologic information, some field measurements carried out for some clearly observed fractured areas helped in identifying the density and the direction of fractures controlling groundwater potentiality. Results indicated that the technique can be applied in similar areas where the carbonate rocks constitute the main reservoir. In the study area, the fractured zone was clearly detected to be extending downward from depth of 15 to 80 m and considered as good aquifer in the area comprising lower resistivity values. Consequently, two different types of water due to different recharge conditions are expected as a result of variation in fractures discontinuity.   Key words: Water, flow, facture, resistivity, aquifer, Sinai.