Resolving Groundwater Conduits in Hyper-Arid Eroded Karsts Using High-Resolution L-Band SAR and Optical Images

Resolving structural elements in hyper-arid eroded karstic environments is crucial to assess their role as groundwater conduits governing the dynamic of these complex and least characterized hydrogeological systems. Of particular interest is the fine mapping of fractured carbonate sedimentary formations in Qatar Peninsula as it provides crucial insights into characterizing the dynamic of karst systems in fossil aquifers. To achieve this objective, we vectorize 3107 km of transverse tension fractures and joints at a 1:6000 scale, trending WNW-ESE and W-E around the N-S Qatar-Arch anticline in Qatar, using both L-Band SAR orbital scenes and high-resolution aerial photography. We distinguish three highly fractured areas of 15x15 km each that are correlated to areas showing upward leakage and groundwater mounding. Our preliminary results suggest these fractures to act as vertical and horizontal conduits for groundwater, from the different fossil aquifer systems in the Qatar peninsula. Validations using semi-empirical backscattering model derived from SAR and ground penetrating radar acquisitions as well as correlation to potentiometric and Total Dissolved Solids maps will be necessary to further quantify the phenomena.