This project supports a collaborative research between Dr. Cordula Robinson, Center for Remote Sensing, Boston University, Boston and Dr. Hesham El-Kaliouby, National Research Center (NRC), Cairo, Egypt. In this research the PIs will use a new approach utilizing space-borne radar and thermal imagery, GIS and geophysical techniques to: analyze the influence of structures on drainage; identify those structures recharged by groundwater, and in which groundwater resides or is transmitted; and determine locations with enhanced groundwater accumulation, in the area between 22 to 23 degree N and 30.5 to 31.5 degree E, south of the Tushka canal in southwest Egypt. The study area is underlain by the Nubian aquifer system that is considered to be unconfined whereby groundwater resides in sandstone rocks that unconformably overlie basement rocks and are covered by Quaternary deposits. The aquifer, however, is not homogeneous, but has a variable nature in that the groundwater present depends on: 1) recharge in the geologic past; and 2) fracturing, which introduced secondary porosity into the rocks and increased their storage capacity. To characterize this variability, the spatial organization of near-surface fluvial features and associated structural features will be derived using space-borne radar and thermal images and Digital Elevation Models (DEMs) in a Geographical Information System (GIS) database. These vector layers will be combined with a DEM to obtain further hydro-morphological parameters and hydrological properties for the defined drainage basins, and to identify those structures requiring field investigation. Geophysical profiling will be used to this end to provide information about the subsurface distribution and relative water content of the faults, as well as aquifer depth. The use of a GIS will allow the necessary scale transformations to be easily resolved. The collaborative project resulted from an NSF-supported workshop held in Cairo, in December 2003, on "Assessing and Managing Surface and Groundwater in Egypt". The Intellectual Merit: The RS and GIS process-flow routine established to meet the objectives of this proposal, and the availability of advanced geophysical profiling techniques, will allow the theoretical deductions made to be tested empirically. The creation of the database and the correlation of the datasets to be used ensure a new and improved understanding of the drainage systems, structural controls, and groundwater distributions in the study area. The approach is innovative and access to all the datasets required makes the goals of the project achievable. The Broader Activities: Results will establish how structures influence drainage patterns and groundwater distributions in the unconfined Nubian aquifer for the study area; thus, it can be determined if the method devised in this pilot study can be applied to other areas in the Great Sahara. Understanding the structural setting and the potential distribution of faults that received most recharge is also significant in building development that is anticipated for this area. Faults with increased pore fluid pressure have increased seismic vulnerability; thus, must be flagged in building development plans. Results will be published in peer-reviewed scientific journals, and the new database will be made available over the Internet at BU. This project is being supported under the US-Egypt Joint Fund Program, which provides grants to scientists and engineers in both countries to carry out these cooperative activities.
