Abstract :
In arid regions, where no renewable surface water is available, groundwater is considered a vital resource. Exploration and assessment of groundwater resources and aquifer systems are very challenging tasks. Recently, airborne electromagnetic survey is used to provide a method for rapid monitoring of large areas and mapping subsurface hydrologic and geological features within 150 to 300 m of the surface. Airborne electromagnetic survey is used to provide information on aquifer thickness, depth to the top of the magnetic basement, location of major faults, dykes and sills. This information along with data from existing deep boreholes, can be used to characterize the water-bearing formations and develop a geological model for the area. In 2001, high-resolution TEMPEST airborne geophysical surveys were flown in Al Khazna area, some 80km to the east of the city of Abu Dhabi in the UAE to acquire time-domain EM (TDEM) and magnetic field data. The survey, flown at 200-m line spacing over a 160 km^2 area, identified and assessed groundwater formation and salinity. This model defined the spatial and vertical extension of the aquifer formation and groundwater bearing types. A significant portion of the area is under cultivation. Hydrogeological control was provided by existing groundwater boreholes, both within and immediately outside the survey area. Changes in relief of approximately 50m are caused by Aeolian sand dunes running ENEWSW with the higher ground being in the east.
