Shuttle Radar
Topographic Mission (SRTM) data have been used in this study for
mapping the terrain characteristics for Egypt. The SRTM 30 Arc. Second
(=900 meter) resolution data is found to be the most suitable for
national scale mapping. The Egyptian political boundary was used to
clip USGS GTOPO_U30 topo data Digital Elevation Model (DEM) for the
Egyptian terrain. Using the DEM produced by the SRTM, different GIS
layers were created using the ARC/GIS 9.0 software. These layers
include all the necessary base map layers for terrain analysis, namely
contour, elevation zones, slope angle, aspect, drainage network and
basins. Each layer map gives a clear idea about one parameter of the
terrain as elevation zone map displays the topography distribution,
highest and lowest altitudes. Slope angle map shows the distribution of
steep and gentle slope areas in Egypt. Aspect map explains the
direction of the land surface slope differentiating as example areas
facing north from others facing south. Maps of the drainage network and
basins outline the Egyptian terrain into different watersheds regarding
the surface runoff and consequently point out areas vulnerable to flash
flood hazard and others capable for ground water recharge. The relative
moisture index was derived from the catchment areas and the slope
layers. Using the land cover map of Egypt prepared by the FAO Africover
project, the loose sand and sand dunes class was selected and overlaid
on the elevation and slope maps in a GIS model to point out the hot
spots for unstable more active loose sand bodies. Various parameters
affect the sand dune movement are known to be the prevailing wind
directions and speed, humidity, vegetation, soil moisture, etc. this
paper is concerned only with three parameters affecting the sand
movement which are relative moisture index, terrain surface elevation
and slope variables. The study of terrain characteristics is essential
for strategic planning and pre-planning decisions and for environmental
management for sustainable development. An application of the physical
environment base map layers, produced from our work, was used to
explore some locations of the road network in the Egyptian terrain that
are subjected to active, less stable sand bodies.