HR: 1330h
AN: H52A-1182    [PDF]
TI: When did the Nile Begin?: Remote Sensing Analysis of Paleo-drainages Near Kom Ombo, Upper Egypt
AU: * Hinz, E A
EM: eahinz@utdallas.edu
AF: Center for Lithospheric Studies, The University of Texas at Dallas P.O. Box 830688, Richardson, TX 75083 United States
AU: Stern, R J
EM: rjstern@utdallas.edu
AF: Center for Lithospheric Studies, The University of Texas at Dallas P.O. Box 830688, Richardson, TX 75083 United States
AU: Thurmond, A K
EM: allie@utdallas.edu
AF: Center for Lithospheric Studies, The University of Texas at Dallas P.O. Box 830688, Richardson, TX 75083 United States
AU: Abdelsalam, M G
EM: abdels@utdallas.edu
AF: Center for Lithospheric Studies, The University of Texas at Dallas P.O. Box 830688, Richardson, TX 75083 United States
AU: Abdeen, M M
EM: m_m_abdeen@hotmail.com
AF: National Authority for Remote Sensing and Space Sciences, P.O. Box 1564, Cairo, 11241 Egypt
AB: The geomorphology of Southern Egypt is dominated by numerous dry riverbeds termed wadis, many of which formed before the modern transcontinental Nile began flowing north. Many of these are relict channels that formed part of an older (Late Miocene) drainage system that flowed westward from the Red Sea Hills and only drained the area of modern Egypt. This older drainage was disrupted and reworked by the modern north-flowing Nile in the mid- to late Pleistocene but is well-preserved in the hyper-arid Sahara and can be studied using remote sensing images. Various optical and radar data along with digital elevation models (DEM) extracted from Shuttle Radar Topography Mission (SRTM) data were used in combination to map and establish the chronological order of different drainage systems and to study the drainage reorganization in southern Egypt. Remote sensing analysis revealed stream capture events in the region around the city of Kom Ombo, on the northern flank of the Nubian Swell. The images show that the older, west-flowing Wadi Abu Suberia has been captured by the north-flowing wadis of Ellawi and Kharit. These streams may owe their aggressive headwater erosion to development of the east-west trending Kom Ombo graben. Analysis of SRTM DEMs shows that the drainages in southern Egypt are dominantly oriented east-west and flow into the Nile. SIR-C radar images reveal that Wadi Kubbaniya, located immediately west and across the Nile from Wadi Abu Suberia and now draining east, was once the downstream section and Wadi Abu Suberia the upstream section of the same river. This W- to NW- flowing drainage has been referred to as the Kubbaniya Nile. The Kubbaniya Nile can be traced on the SIR-C images as far north as the southernmost extent of the Gallaba Gravel Plain where it is lost under Quaternary gravel and sand deposits. Analysis of the present-day drainage using SRTM DEMs suggests that a subtle channel runs north through the Gallaba Plain and joins the Nile channel further upstream. This study indicates important neotectonic movements of the E-W trending Nubian Swell centered on the Egypt-Sudan border during Plio-Pleistocene times caused a massive reorganization of drainages in southern Egypt and allowed the Nile to flow north across the swell. These observations are also important for identifying and exploiting groundwater resources in the region. Ancient paleochannels of the Kubbaniya Nile and other components of the pre-Nile drainage system are promising locations to explore for groundwater. Establishing a chronology for when the east-west trending drainages were disrupted can be used to constrain when the modern, transcontinental Nile began to flow across the Nubian Swell.
DE: 1824 Geomorphology (1625)
SC: Hydrology [H]
MN: 2003 Fall Meeting