The state of the art in salinity mapping is that highly saline areas can be separated from
non-salinized areas (e.g., Vidal and Sagardoy, 1995). Most of the published investigations
based on remote sensing distinguish only three to four classes of soil salinity, after
consulting geomorphologic or soil degradation maps or by means of conventional timeconsuming
and laborious field surveys. Current sensors and interpretation algorithms do
not allow the detection of intermediate to medium salinity levels. Salinization affects the
leaf angle orientation (leaf roll) and increased chlorosis, which is best-observed in the
near and middle infrared bands (Steven et al., 1992). The final stage of soil salinization is
an increased brightness, detectable from the visible part of the spectrum (albedo high, leaf
area index low). A new approach to quantify the physical appearances through
biophysical parameters of salt-afflicted crops (e.g., surface albedo, fractional vegetation
coverage, LAI, surface resistance, evaporative fraction) was tested by Ambast et al.
(1999) and is worth expanding further. A simple combination of multi-spectral bands
without any classifier provides meaningful information. A quantitative interpretation into
soil salinity classes can be made after extensive field visits. More research is needed for a
rapid appraisal of salinity from satellite measurements.
The state of the art in salinity mapping is that highly saline areas can be separated fromnon-salinized areas (e.g., Vidal and Sagardoy, 1995). Most of the published investigationsbased on remote sensing distinguish only three to four classes of soil salinity, afterconsulting geomorphologic or soil degradation maps or by means of conventional timeconsumingand laborious field surveys. Current sensors and interpretation algorithms donot allow the detection of intermediate to medium salinity levels. Salinization affects theleaf angle orientation (leaf roll) and increased chlorosis, which is best-observed in thenear and middle infrared bands (Steven et al., 1992). The final stage of soil salinization isan increased brightness, detectable from the visible part of the spectrum (albedo high, leafarea index low). A new approach to quantify the physical appearances throughbiophysical parameters of salt-afflicted crops (e.g., surface albedo, fractional vegetationcoverage, LAI, surface resistance, evaporative fraction) was tested by Ambast et al.(1999) and is worth expanding further. A simple combination of multi-spectral bandswithout any classifier provides meaningful information. A quantitative interpretation intosoil salinity classes can be made after extensive field visits. More research is needed for arapid appraisal of salinity from satellite measurements.
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