An Integrated Approach (Remote Sensing, GIS, Geochemistry, Field, Geophysics) for Assessment of Groundwater Potential in Large Transcurrent Fault Systems
Abstract
We assessed the ground water potential for major transcurrent fault systems in basement complex terraines using as our test case, the extension of the Najd transcurrent Shear System (NSS) of the Eastern Desert of Egypt, the largest (length: 1600 km; width: 200 km) recognized pre-Mesozoic (550-630 Ma) transcurrent fault system. Spatial analysis (in a GIS environment) of remote sensing data together with relevant geologic (e.g., geologic maps), hydrologic (e.g., depth to water table), and geochemical (e.g., anions, cations) and isotopic (O, H, and tritium) data sets revealed a causal association between the locations of productive wells and distribution of NSS structural elements (faults, shear zones, mélange, dykes) within highly fractured domains. Specifically at: (1) intersection of Najd shear zones and fault systems, (2) intersections of two or more fault systems, (3) intersections of Najd-related dykes with main valleys, and (4) within tectonic mélange. For each reservoir type, reservoir-specific field and satellite-based characteristics were identified and used in conjunction with complementary data to target reservoirs of similar settings. Postulated well locations were then successfully tested using VLF technologies. Utilizied remote sensing data include: (1) Landsat TM bands, TM band ratio, and SIR-C for identification of lithologies and mapping structures; (2) TRMM and SSMI for precipitation, (3) SRTM for delineation of watersheds and stream networks, and (4) NDVI (from Landsat TM) and soil moisture (from AMSR) as proxies to locations of shallow groundwater. Results highlight the importance of major transcurrent fault systems for trapping and storing groundwater and serve as a replicable model for regional assessment of groundwater potentials in arid lands elsewhere.
- Publication:
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AGU Spring Meeting Abstracts
- Pub Date:
- May 2007
- Bibcode:
- 2007AGUSM.H51C..06S
- Keywords:
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- 0925 Magnetic and electrical methods (5109);
- 1829 Groundwater hydrology;
- 1855 Remote sensing (1640);
- 8005 Folds and folding