604 
MAP OF SOIL CONDITIONS 
images is the only possible way to understand the 
relationship between specific landscape elements and 
the dominant processes in large areas. Enlarging the 
landsat images made the mapping easier. Aerial photo 
graphs, with a higher resolution, are necessary for 
understanding and observing the morphologic charac 
teristics of smaller landforms. Information obtained 
at a lower level of observation may then be extrapo 
lated to higher levels of observation. 
7.2 Multi spectral sensing 
Multispectral imagery provides more information than 
data collected in a broad spectral band. Different 
phenomena ; the condition of the vegetation and diffe 
rences in soil conditions show a specific spectral 
reflectance only discernable on multi-spectral images. 
Field work and laboratory analysis are necessary for 
understanding the relation between certain phenomena 
and their recorded reflection. 
With a visual or an analog interpretation a general 
mapping could be performed on a scale of 1:250,000 
and for some areas upon a scale of 1:100,000 with a 
reasonable accuracy. This method is most suitable for 
the assessment of the factors leading to desertifica 
tion. 
8 . APPENDIX 
1.- Macrophotomorphic units 
The macro PMU's were delineated according to the do 
minating colour. The colour scale of the "Manual of 
colour photography 1968" was used for the colour de 
scription. The mentioned numbers on the maps corres 
pond to the following colours : 
scale 
n° colour 
scale 
n° colour 
scale 
n° colour 
2 
S. pink 
27 
deep Y 
pink 
134 
V.L.Y.G. 
3 
deep pink 
28 
L.Y pink 
135 
L.Y.G. 
4 
L. pink 
29 
m Y pink 
136 
m Y.G. 
5 
m. pink 
35 
S. ro 
153 
g white 
7 
P. pink 
36 
deep ro 
180 
V.L.B. 
11 
v. red 
37 
m. ro 
184 
v. p. B. 
12 
S. Red 
40 
S.rBr 
189 
b white 
13 
deep Red 
115 
v.y.G. 
248 
deep p pK 
16 
d. Red 
116 
brill Y G 
249 
L.p.pK 
25 
v.y. pink 
119 
L.y.G. 
251 
d.pK. 
26 
S.y.pink 
121 
p.y.G. 
263 
white 
* S = strong ; L = light ; m = medium ; v = very ; R = Red; 
B = blue ; G = green ; p = purple ; y = yellow ; 
ro = orange. 
VThenever more than one colour exist, a combined code 
is used, e.g. : 
R(y) = red with inclusions of yellow 
R/v = both colours exist but red is dominant 
R-y = both colours exist at the same proportion. 
colour, te 
of shape c 
1. ) coloui 
ler units 
2. ) textui 
categories 
3. ) qualit 
X = very c 
Y = not dj 
4. ) homogs 
H = homogs 
h = heterc 
5. relati\ 
b. = relat 
9. REFEREi 
Butzer, K, 
Egypt d\. 
Egypt 3 i 
El-Baz, F. 
earth oi 
Sens. 44 
El-Baz, F. 
from spc 
Advances 
developr 
El-Baz, F. 
South Ws 
region c 
p. 3017- 
El-Hag, M. 
landsat 
versitei 
El-Shazly, 
M.A. El- 
S. Sanac 
imagery 
in the C 
ternatic 
ment, Aj 
Gad, A. & 
vial act 
in the ] 
symposia 
characts 
studies 
2-6 Decs 
Justice, ( 
ground < 
shend (e< 
p. 38-5! 
Kishk, N.i 
damage c 
symposii 
tility ; 
Assiut, 
Lillesand 
and imac 
John Wi! 
resource 
J.R.G. ' 
sensing 
Monir, M.l 
deposit: 
Desert I 
Murray, G 
outline 
Rapp, A. 
water, t 
versitel 
Said, R. ! 
York anc 
Salem, M.l 
of the I 
Mins. Cc 
UNEP, 198! 
UNEP. 
Delineation of the photomorphic units (PMU) 
2.- Micro PMU 's were delineated by using the criteria 
indicated in the following descriptive formula :