“The aim of this paper is to identify the change in saline soils (Sebkha) using Remote Sensing (RS) and geographic information system (GIS) techniques”.

1. Assessment of Spatial and Temporal
Variations of Soil Salinity using Remote
Sensing and Geographic Information
System in the north west of Libya.
Hamdi Zurqani, Bashir Nwer and Ezzdein Rhoma
GEOS 2012
DepartmentNaturalResources

2. University
of TripoliAssessment of Spatial and Temporal Variations of Soil Salinity
using Remote Sensing and Geographic Information
in the north west of Libya.
DepartmentNaturalResources
• Introduction
• Aim
• Methodology
• Findings
• Conclusion
MR. HAMDI ZURQANI GEOS 2012

3. University
of TripoliDepartmentNaturalResources Introduction
The study area is located in extensive area of coastal
salt flats, locally known as“sabkha". The study area is
situated the between the longitudes (12°15 - 11°33)
and (32°30 - 33°10) north.
The total area of ​​the study area of about 221,689 hectares
Location
of study area
MR. HAMDI ZURQANI GEOS 2012

4. University
of TripoliDepartmentNaturalResources Introduction
• Desertification and land degradation are the main
problems facing arid and semi-arid regions.
• Soil salinity problems in Libya started to be noticed
after the extensive agricultural activities, coupled
with increasing population, through the use of
lands suitable for farming and overdraw of fresh
groundwater to an extent of causing seawater
intrusion.
• In addition, the nature of harsh climate featuring
low amount of rainfall ranges, and high
temperatures are also contributes to the soil
salinity problems.
MR. HAMDI ZURQANI GEOS 2012

5. University
of TripoliDepartmentNaturalResources Introduction
• Saline soils in Libya cover around 12 % of the north
region, 16.5% of the west region and 23.4% of the
middle region.
• Remote sensing techniques are very useful for
monitoring and control of salinity problems
especially in arid and semi-arid environment due to
sparse vegetation cover.
• The integration of remote sensing data, in the form
of satellite imagery, with the GIS has boosted up the
ability of delineating and mapping soil salinity.
• hese paper asses the change of salt-affected areas
from 1971 to 2001 along the coastal area in the
north west of Libya.
MR. HAMDI ZURQANI GEOS 2012

6. University
of TripoliDepartmentNaturalResources Aim of the paper
The aim of this paper is :
“To aim of this paper is to identify the change in
saline soils (Sehbkha) using Remote Sensing (RS)
and geographic information system (GIS)
techniques”.
MR. HAMDI ZURQANI GEOS 2012

7. University
of TripoliDepartmentNaturalResources Methodology
The assessment of the salinity has been
structured under two main phases:
1. Soil Salinity Detection Using Remote
Sensing and GIS.
Remotely sensed data, multi–temporal Landsat-7
ETM image (Enhanced Thematic Mapper)
acquired in 1971, 1987 and 2001 has been used
to detect coastal saline areas.
MR. HAMDI ZURQANI GEOS 2012

8. University
of TripoliDepartmentNaturalResources Methodology
2. Site Observations.
• Soil samples were collected from the study in
two different sites ( Zolten and Abukmash).
• The selection of the Sebkhes were based upon
the distance to sea and the area were the
saline soils area are found to be decreased.
MR. HAMDI ZURQANI GEOS 2012

9. University
of TripoliDepartmentNaturalResources Findings
1. Detection Using Remote Sensing Data
Visual assessment were conducted for satellite
images data for the years 1972, 1987 and 2001.
The results show that in 1972 the soil saline area
covered about 43,639 hectares.

10. University
of TripoliDepartmentNaturalResources Findings
1. Detection Using Remote Sensing Data
And in 1987 is decreased to 40,898 hectares.
MR. HAMDI ZURQANI GEOS 2012

11. University
of TripoliDepartmentNaturalResources Findings
1. Detection Using Remote Sensing Data
And in 2001 is decreased to 38,043 hectares.
MR. HAMDI ZURQANI GEOS 2012

12. University
of TripoliDepartmentNaturalResources Findings
2. Temporal and Spatial Variations in Soil
Salinity
• The area of saline soils has decreased through
the last 29 years.
• For instance, in a period of 15 years (1972-
1987), the area of saline soil decreased by
6.28 % .
• The total Sebkha’s area in the period of 29
years (1972 to the year 2001) has decreased at
a rate of 12.82%.
MR. HAMDI ZURQANI GEOS 2012

13. University
of TripoliDepartmentNaturalResources Findings
2. Temporal and Spatial Variations in Soil
Salinity
MR. HAMDI ZURQANI GEOS 2012

14. University
of TripoliDepartmentNaturalResources Findings
For further assessment of the salinity patterns in
the study area two sites were selected to collect
soil samples for ground truth.
• Soil samples were collected from the study in
two different sites (Zolten and Abukmash).
(Abukmash Shbkha)(Zolten Shbkha)
MR. HAMDI ZURQANI GEOS 2012

15. University
of TripoliDepartmentNaturalResources Findings
• The results revealed most of the study area
soils are saline soils. Aridisols are the main
soils in the two sites.
SOIL CLASSIFICATION FOR THE STUDY AREA
(USDA SOIL TAXONOMY)
Soil Classification ( USDA Soil Taxonomy)
Abukmash site Zolten Site
Calcic Aquisalids
Calcic Petrocalcids
Natric Petrocalcids
Calcic Haplosalids
Xeric Haplocalcids
Calcic Haplosalids
Lithic Haplosalids
MR. HAMDI ZURQANI GEOS 2012

16. University
of TripoliDepartmentNaturalResources Findings
• The outputs from the data analysed from remote
sensing or concluded from soil samples results
show that there were a decrease in the area
covered by saline soils.
• The decrease in soil saline area can be explained by
the sand movements which covered the soil surface.
• The sand movements prevent remote sensing
technique from picking up saline soils in the study
area.
• Therefore, a methodology based on site observation
and remote sensing techniques can be an optimal
tool to map soil salinity spatially and in time scale.
MR. HAMDI ZURQANI GEOS 2012

17. University
of TripoliDepartmentNaturalResources CONCLUSION
• The remote sensing and GIS, cheaper and faster
technique than the traditional ones in delineating
and mapping soil salinity.
• Soil salinity is considered as an important factor in
desertification in arid regions and semi-arid regions
such as Libya.
• Developing a model integrate remote sensing and
GIS techniques with site observation to optimize the
accuracy of the outputs to be used in rehabilitations
programs of saline soils is the only way forward for
soil salinity assessment, especially in Libya.
MR. HAMDI ZURQANI GEOS 2012

18. DepartmentNaturalResources