Modelling the backscattering coefficient of salt-affected soils: Application to Wadi El-Natrun bottom, Egypt
Ziad Aly, Ferdinand Bonn and Ramata Magagi
Abstract
One of the most
crucial environmental problems affecting developing countries in arid and
semi-arid regions is soil salinity. Its detection using radar imaging systems
is one of promising domains of remote sensing research. Detection is based
essentially on the relationship between the quantity of existing salts in the
soil, the soil moisture content, and the dielectric properties of this mixture.
Due to the components of the mixture and their corresponding dielectric
properties, backscattering of these types of soils can be modelled and
monitored. Parameters influencing the radar detection of salt-affected soils
are grouped into two main groups: those related to the sensor and those related
to the target. Some of these parameters cause information attenuation during
monitoring of the salt-affected soils; however, others give us information that
help to better understand the phenomena. Some of the latter parameters can be
controlled and others are imposed. Most previous studies neglected the effect
of the presence of salts combined with the other parameters on the backscattering
coefficient. In this paper, we present the salinity effect on the calculation
of the backscattering coefficient using several backscattering models. The
results show that the high dielectric constant, due to the extensive presence
of salts, has a significant effect on the backscattering value. To validate the
modelling approach with actual data, four RADARSAT-1 satellite images in
standard modes were selected for the area of Wadi El-Natrun, Egypt, where
fieldwork was conducted simultaneously with some of the RADARSAT-1 image
acquisitions.
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History
Submitted: 03 September 2004
Revised: 07 October 2004
Accepted: 05 November 2004
Citation
Aly Z, F Bonn & R Magagi, 2004. Modelling the backscattering coefficient of salt-affected soils: Application to Wadi El-Natrun bottom, Egypt. EARSeL eProceedings, 3(3), 372-381
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ISSN 1729-3782
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