1. Use of Remote Sensing and GIS in Mapping the
Environmental Sensitivity Areas for Desertification of
Egyptian territory
GAD, A.
Head, Environmental Studies and Land Use Division, NARSS
Abdallagad@gmail.com & gadabdalla@yahoo.com

2. Definition
“Desertification is Land Degradation in Arid,
Semi-arid and Dry Sub-humid Areas resulting
from adverse human impact”
Facts about desertification
1.Affects some 25% of the earth.
2.It seems to be occurring at an accelerated rate globally.
3.The situation is especially serious in Africa, where 66% of
the continent is desert or dry lands, and 73% of the
agricultural dry lands are already degraded.
4.Most of the world’s 800 million people without adequate
food live in the dry lands

3. Desertification is the consequence of a set of important processes, which are
active in arid and semi-arid environment, where water is the main limiting
factor of land use performance in ecosystems
Environment Soil, Climate, Topography, Human activity,….etc.
Environmental systems are generally in a state of dynamic equilibrium with
external driving forces. Small changes in the driving forces, such as climate or
imposed land use tend to be accommodated partially by a small change in the
equilibrium and partially by being absorbed or buffered by the system.
Desertification of an area will proceed if certain land components are brought
beyond specific threshold, beyond which further change produces irreversible
change

4. Desertification Indicators
Those, which indicate the potential risk of desertification while
there still time and scope for remedial action. Regional indicators
should be based on available international source materials,
including remotely sensed images, topographic data (maps or
DEM’s), climate, soil and geologic data
Environmentally Sensitive Areas (ESA’s) to desertification around
the Mediterranean region exhibit different sensitivity status to
desertification for various reasons.
The key indicators for defining ESA’s to desertification, which can
be used at regional or national level, can be divided into four broad
categories defining the qualities of soil, climate, vegetation, and
land management.

5. EGYPT
• In Egypt, 96% of its
territory is desert, while
about 80 million people
live on the rest 4%.
• The inhabited land is
even subjected to
different desertification
processes.
• Urban encroachment
and dereliction of
cultivated land surface
resulted in
disappearance of most
fertile lands from
productivity.

6. Environmental Sensitivity to Desertification
The following three quality indices were computed;
1. Soil Quality Index (SQI),
2. Vegetation Quality Index (VQI)
3. Climatic Quality Index (CQI)
Parent Material
Soil Texture
Soil Quality Index
(SQI) Desertificatio
Soil Depth n Quality
Index (DQI) SQI = (Ip * It * Id * Is) ¼
Slope gradient
Plant Cover and VQI = (I Ep * I Dr * I Vc) 1/3
Vegetation Quality
Index (VQI) Environment
Drought
ally Sensitive CQI = P/PET
Resistance
areas
Erosion protection (ESA’s) DSI = (SQI * VQI * CQI) 1/3
Climatic Quality
Rainfall Index (CQI)
Aridity Index

7. Mapping Soil Quality Index (SQI):
Classes, and assigned weighting index for parent material
SQI = (Ip * It * Id * Is) ¼
Class Class Class
1) Coherent: Limestone, Good 1.0
dolomite, non-friable
sandstone, hard limestone
layer.
2) Moderately coherent: Moderate 1.5
Marine limestone, friable
sandstone
3) Soft to friable: Calcareous Poor 2.0
clay, clay, sandy formation,
alluvium and colluviums
Class Score Area (km2) %
Coherent 1 179616.39 18.01
Moderately 1.5 338890.46 33.97
Coherent
Soft to friable 2 479009.13 48.02
Total - 997515.98 100

8. Mapping Soil Quality Index (SQI):
Classes, and assigned weighting index for soil texture
SQI = (Ip * It * Id * Is) ¼
Score
Texture
Classes Description
Areas Areas
dominated by dominated by
water erosion wind erosion
Not very Loamy sand, Sandy 1 1
light to loam, Balanced
average
Fine to Loamy clay, Clayey 1.33 1.66
average sand, Sandy clay
Fine Clayey, Clay loam 1.66 2
Coarse Sandy to very Sandy 2 2
Class Description Score Area (km2) %
Very light to Loamy, Sandy, 1.00 167425.65 16.78
average Sandy-loam,
balanced
Fine to Loamy clay, Clayey- 1.33 16994.83 1.70
average sand, Sandy clay
Average Clay, Clay-Loam 1.66 82299.74 8.25
Coarse Sandy to Very sandy 2.00 730795.76 73.26
Total - 997515.98 100

9. Mapping Soil Quality Index (SQI):
Classes, and assigned weighting index for soil depth
SQI = (Ip * It * Id * Is) ¼
Class Description Score
Very deep Soil thickness is more than 1 meter 1
Moderately Soil thickness ranges from <1m to 0.5 1.33
deep m
Shallow Soil thickness ranges from <0.5m to 1.66
0.25 m
Very Shallow Soil thickness 0.15 m 2
Class Score Area (km2) %
Very deep 1.00 441126.17 44.22
Deep 1.33 265446.21 26.61
Shallow 1.66 47103.87 4.72
Very Shallow 2.00 243839.73 24.44
Total - 997515.98 100

10. Mapping Soil Quality Index (SQI):
Classes, and assigned weighting index for Slope gradient
SQI = (Ip * It * Id * Is) ¼
Classes Description Score
< 6% Gentle 1
6 – 18 % Not very gentle 1.33
19 – 35 % Abrupt 1.66
> 35 % Very abrupt 2
Class Score Area (km2) %
Gentle 1.00 57134.61 5.73
Not very gentle 1.33 217333.01 21.79
Abrupt 1.66 276935.89 27.76
Very abrupt 2.00 446043.05 44.72
Total - 997515.98 100

11. Soil Quality Index (SQI)
SQI = (Ip * It * Id * Is) ¼
Parent Material Soil Texture Soil Depth Slope Gradient
Class Description Range
1 High quality >1.13
2 Moderate quality 1.13 to 1.45
3 Low quality > 1.46
Class Score Area (km2) %
Very Low Quality > 1.6 646757.90 64.84
Low Quality 1.4 -1.6 131656.25 13.20
Moderate Quality 1.2-1.4 219032.41 21.96
Total 997515.98 100

12. Mapping Vegetation quality index (VQI)
Erosion Resistance Vegetation Cover
Erosion Protection
VQI = (I Ep * I Dr * I Vc) 1/3
Class Description IEp IDr IVc
1 Perennial cultivation 1 1 1
2 Halophytes 1.33 1 1.33
3 Temporal and orchards, mixed 1.66 1.33 1.66
with crop land
4 Saharan vegetation < 40% 2 1.66 1
5 Saharan vegetation > 40% 2 1 1

13. VQI = (I Ep * I Dr * I Vc) 1/3
Class Area (km2) Drought Erosion Vegetati
resistance protection on cover
scores scores scores
Cultivated Land 45536.36 1.00 1.00 1.00
Halophytes 13851.56 1.00 1.33 1.33
Orchards Mixed with crop 9388.44 1.33 1.66 1.66
land
Saharan Vegetation >40% 904024.57 1.66 2 2
Saharan Vegetation <40% 24645.63 2.00
Total 997515.98
Class Score Area (km2) %
Good <1.2 34974.9 3.51
Average 1.2-1.4 13851.56 1.39
Week 1.4-1.6 8142.71 0.82
Very week >1.6 940477.39 94.29
Total - 997515.98 100

14. Mapping Climatic quality index (CQI)
CQI = P/PET
Precipitation Potential Evapo-transpiration

15. Climatic quality index
CQI = P/PET
Class Area (km2) %
Hyper-arid 890881.52 89.31
Arid 106634.45 10.69
Total 997515.98 100

16. Environmentally Sensitive Areas (ESA’s)
DSI = (SQI * VQI * CQI) 1/3
Class Score Area (km2) %
Non affected or very low sensitive areas 0.01-1.2 798.01 0.08
Low sensitive areas 1.3-1.4 11072.43 1.11
Moderately sensitive areas 1.4-1.5 41396.91 4.15
Sensitive areas 1.5-1.6 202196.49 20.27
Very sensitive areas 1.7-1.8 742052.14 74.39
Total - 997515.98 100

17. Greater Cairo
URBANIZATION
1978 1984 2006
Feddan/Year %
Urban Increase 1978-1984 1707.1 4.8
Urban Increase 1984-2006 150.2 0.3

18. URBANIZATION
MALAWY
Governorate Year of Acreage Increase of urban Rate of increase (acre/y)
photo & acre area between the
map two studied years
issuing (acre)
El-Menia Ph 1981 76.13 93.92 30.84
Ph 1985 170.05

19. MORPHOLOGY AND DISTRIBUTION OF AEOLIAN
DEPOSITS
Beach area and Sinai Peninsula
• The beach area extends from Rafah, on the eastern border, to Al-Saloum, west
of Egypt. It is characterized by a narrow strip with a maximum width of 20
km.
• Transverse dunes characterize the north and middle Sinai

20. Interference zone between the western desert and
Nile Delta
Very narrow strip in the long stretch between Aswan,
in the south, and El - Fashn city in the north.

21. Interference zone between the western desert and
Nile Valley
The main movement direction, in all
cases, is northwest – southeast.
In most cases, the eastern horns
of the barchans are more
elongated than the western ones

22. Low altitude aerial photographs and submerged areas

23. Barchan dunes in MSS images, west Samalout

24. Irrigation canals blocked by Aeolian deposits

25. Great sand sea – Western Desert

26. East Cairo-El-Khanks area dunes
1. Well developed sand dunes (5 - 40 m
height), following the east-west trend.
2. The primary source of the Aeolian
deposits is the weathered products of the
Miocene and Pliocene rocks surrounding
the Heliopolis basin.
3. The dune types are composed of
longitudinal, barchans and star dunes.
4. Wind velocity range between (12.2 -
16.1 Km/h) which are enough for sand
movement.

27. RISK OF WIND EROSION
1. The dunes and sand sheets of the
Great sand sea and Abu-Moharik
are considered as sources for
sand, which may be transported to
the east by suspension, saltation
or creep to deposit over the
cultivated lands in the valley.
2. Segments of the Nile valley that
are most affected by aeolian
activity have trends oblique to the
direction of the prevailing winds.

28. SALINIZATION
CHANGES IN SOIL SALINITY FROM 1988 AS COMPARED
WITH 1986.
Range of drainage
Soil salinity
water Summary of qualitative changes from 1986 to 1988
category
(soil) salinity - gm/m3
1 < 750 Area increased slightly at the expense of category 2.
2 750 – 1000 Area decreased due to improvement (i.e. changed
to category 1).
3 1000 – 1500 Area decreased due to improvement (i.e. changed to
category 2).
4 1500 – 2000 Area decreased due to improvement (i.e. changed to
category 3).
5 2000 – 3000 Area decreased in delta but additional area was
added to newly reclaimed land west of the delta.
6 > 3000 Area increased on account of category 5.

29. Salt affected soils by drainage mismanagement

30. VEGETATION DEGRADATION
(Unsupervised classification (1988
(Unsupervised classification (1993
(Unsupervised classification (1997

31. Normalized density of Vegetation Index
)(NDVI

32. Conclusions and Recommendations
•The assessment of desertification sensitivity is rather important to plane combating actions
and to improve the employment of natural resources.
•Remote sensing, in addition to thematic maps, may supply valuable information concerning
the soil and vegetation quality at the general scale. However, for more detailed scales,
conventional field observation would be essential.
•The Egyptian territory is susceptible to very high-to-high desertification sensitivity,
however the Nile Valley is moderately sensitive because of its vegetation cover.
•Analyzing the landscape and integrated environmental parameters are useful to point out
the driving forces of desertification. Desertification driving forces include mainly
urbanization, salinization and water logging in the arable land of Nile Valley and Delta. The
interference zones with desert areas and the oases are most affected by wind activity.
•Vegetation degradation is a serious problem in the northern coastal zone causing exposition
of the soil surface to other degradation agents (i.e. Wind activity and flash floods).
•It can be recommended that mathematical modeling should be developed for the operational
monitoring of different elements and processes contributing to desertification sensitivity.