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The aims of this paper are: (1) monitoring changes on
landuse-landcover of the area extending from Gamasa to
Baltim towns (140 km) and extended about 20 km to the
south. The study area is bordered by the Mediterranean Sea
from the north and the old cultivated land from the south,
(Fig. 1), (2) studying the impact of sea wave currents in the
erosional and depositional actions along the coast line, and
(3) studying the effect of active sand dunes on the
infrastructure and human activities in the study region.
2. MATERIALS AND METHODS
2.1. Material
1- Landuse-landcover map (1:100,000) based n SPOT
XS data of 1991, produced by the Remote Sensing
Unit of SWERI.
2- Landsat TM image of 1990.
3- SPOT XS image of 1995.
4- Several field visits and soil sampling and analysis from
selected sites using GPS.
5- Aerial photographs of (1983) scale 1:20,000.
2.2. Methodology
1- Interpretation of Aerial photographs for producing
geomorpho-logical maps at a scale of (1:20,000).
2- Image processing includes;
a) Unsupervised classification of Landsat TM and SPOT
data using IMAGEN Package (ISODATA)
program.
b) Principle component Analysis (PCA) of Landsat
TM data.
c) Hybrid classification and statistical analysis of the
classified units, (1990-1995).
3- Ground measurements and laboratory analysis.
RESULTS AND DISCUSSION
3.1- Geomorphology of the study area
The interpretation of aerial photographs and terrain
analysis of the studied region produced a geomorphologic
map that shows the major land forms represented by:
beach, sand plan, dunes, old beach ridges, wetland, sabkha
and evaporate crusts. Each land unit has been investigated
in the field, and the main geomorphic processes such as
wind erosion in the form of sand removal from the root
zone of palm trees, or sand deposnition on the road,
setelments and cultivated land.
3.2.1-Landuse-landcover classification
The application of hybrid image classification technique to
Landsat TM data acquired in 1990 (Fig. 2a) reveals that the
main landuse-landcover classes are; water bodies, shallow
water, sabkhas, cultivated land, sand dune, bare soil, urban,
and reclaimed land. However, the classification of the
SPOT image of the same area aquired in 1995 (Fig. 2b)
shows clearly the increase of the total area of some classes
on the expense of others.
The comparison between the statistical data of the used
SPOT and Landsat TM images reveals that the landuse-
landcover has been changed dramatically within five years.
The data in Table (1) show that:
a) There is an increase in the area of the wetland and
waterlogging regions due to the establishment of fish
farms, extension of rice growing fields and high water
table level, (Eweida et al., 1997).
b) The total area of cultivated land is approximately
doubled, due to land reclamation activities.
c) Vast areas of sabkhas and sand areas have been
converted to productive land.
Table (1) Changes in landuse-landcover in (km?) between
(1990-1995).
Land unit Landsat TM 1990 SPOT 1995
(km?) (km?)
Water bodies 10.8 11.6
Agriculture 13.0 24.5
Reclaimed land 20.9 30.3
Sabkhas 524 41.5
Sand dunes 265.6 177.8
Windblown sand 189.8 167.0
3.3. Erosion and accretion processes along the coast line
Application of multi-temporal analysis of remote sensing
data and the interpretation of the existing maps of the study
area enabled in predicting changes along the coastline. The
principle component analysis (PCA) of the Landsat
Thematic Mapper data assisted in determining the newly
formed areas (spils formation).
In most of the studied sites (1.e. Baltiem, Ras El Bar and
Gamasa), accretion occurs in the eastern side of the eroded
areas due to the west to east direction of active wave
current.
Intemational Archives of Photogrammetry and Remote Sensing. Vol. XXXII, Part 7, Budapest, 1998
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