17-71 16,f-"i,Y,K,l> 
3/189, C.Y.h.P 
rim 263/189,m-f,Y,h,2 
17771 119-189(263) ,f-m,Y,h, 
P/'b 
ICrm 189-263,c,Y ,h,P/b 
TTH I2,,l,x,h,p/b 
I I 2S3,f,Y,h,P/b 
IS~a 7/263,m,Y,b,b/P 
i»T»1 13,f-m,X,!l,P/b 
Fig. 5 - Multistage analysis of a oart of the eastern desert, near to the Mile Valley 
A. Micro ohotomorphic jnits 
8. An aerial photograph (scale !:4G,000) 
was responsible for the erosion of debris and its 
transportation northward in a manner similar to that 
of the present day River Nile system (El-Baz 1979). 
The field observation confirmed that composite dark 
patches indicate the desert pavements surrounded by 
the light coloured sand sheet. It was also possible 
to conclude that the dark coloured linear patterns 
in the sand dune area are gravelly surface corridors 
The desert pavements and the gravelly dune corridors 
are protecting the underlaying sandy material. 
4.2 Eastern desert 
The colour composites revealed the rugged landscape 
of the Eastern desert in different dark shades. Com 
parison between the image interpretation and the geo 
logic map made it possible to attribute to the diffe 
rent colours a geologic meaning. It was possible to 
map the dense network of wadies and ravines, which 
are characterized by a distincet bright colour. The 
photomorphic u'nits on the macro and micro levels 
made the delineation possible of high altitude areas 
with a dense dendritic drainage pattern and the down 
slope area of debris accumulation, characterized by 
a light colour and a poor drainage network. 
The study of aerial photographs made it possible 
to follow the shape and path way of the wadies and 
its tributaries by using the elements of tonality, 
texture and relief. It was found that the dendritic 
drainage pattern is the basic type in the Eastern 
desert, especially in the upper plateau. 
The bright colour patches found in the colour com 
posites of the adjacent part of the Nile Valley and 
in the wady bottoms(fig. 5A) were studied in detail 
on aerial photographs. It corresponds to the modified 
A 36/119 (37) 
6 37/119 
1 119(271/27(119) 
C 119(23) 
L 121(263) 
1. 36.Î.Y.H.P 
2. 37(119) ,ir.,Y,H,P 
3. 119,f,X,H,b 
1. 37,f,X,H.P 
2. 119,f,X,H,fc 
1. 119(27),c,Y,H,P 
2. 27,f-m,Y,H,b 
3. 119,f,Y,H,b 
1. 28,f,Y.K,b 
2. 11S,f,Y,H,b 
1. 12,f,Y,H,b 
1. 263,f,Y,H,b 
Fio. 6 - Pnotomorphic units for a part of the Nile Valley. 
dendritic (e.g. Dichotomic) and to the braided river 
pattern (fig. 5B). 
These patterns are indicative for depositional pro 
cesses and are associated with a coarse soil mate 
rial. 
The following landscape forms could be distinguished; 
1. The existence of a cradle shaped valleytype in the 
broad gently sloping shallow valleys in the down slope 
area. This valleytype indicates a low rate of erosio- 
nal force or a large rate of debris accumulation. 
2. The existence of a V-shaped valleytype in the low 
order tributaries of the upper plateau. This valley 
type indicate a strong vertical erosion. 
3. The U-shaped valleytype is occuring in the main 
valleys. That type of valley might be developed after 
a strong vertical erosion, or where the pathway 
followed a fracture or reached a hard rock. 
We may conclude that the Eastern desert is charac 
terized by a dominant fluvial erosion, especially 
during the thunderstorms. The eroded material is de 
posited in the old wadies and ravines. The debris 
material is transported and accumulated in the adja 
cent part of the cultivated Nile Valley. 
The interpretation of enchanced landsat images of 
the Nile Valley resulted in eleven PMU's different 
in the dominant colour, texture, unit boundaries, 
homogeneity and relative size. Each of these PMU's 
could be subdivided into a number of microphotomorphic 
units (fig. 6 ). 
The dominant colour gives some information about the 
vegetation cover. Where no red or green is visible, 
the vegetation cover is regarded as less than 1%, 
faint green-brown or green-brown 20-40%., a faint 
brown-red 40-60%, a pronounced brown-red or magenta 
60-80% (Mitchell 1931). It is obvious that the micro 
photomorphic units characterized by the red colour 
are dominating inside the valley, whereas they become 
less important toward the desert fringes. A photomor 
phic unit of almost faint green colour and fine tex 
ture is bordering the cultivated Nile Valley on the 
West. 
Field work confirmed that the desert fringes are 
mostly covered by grasses and dead vegetation resul 
ting in the faint green colour on the colour compo 
sites. Inside the valley, the crops are strong and 
have an active photosynthesis. Some areas inside the 
valley are reflecting strongly in the near infra red 
radiation of the E.M.S.-resulting in a continuous 
602