Fig. 5From: Hydrological problems of flash floods and the encroachment of wastewater affecting the urban areas in Greater Cairo, Egypt, using remote sensing and GIS techniquesa A sample of the scanned 1:50,000 topographic maps used to create a 20 m resolution DEM and to map the alluvial channels now concealed by the urban areas, b the digitized contours of the study area, and c the created DEM from the topographic contour maps, note the extent of Wadi Degla catchmentBack to article page