Abstract form

Application of remote sensing to soil salinity mapping in the arid
region (Iran)
M. TAZEH 1 , R. TAGHIZADEH MEHRJARDI 2 , Sh. MAHMOODI 3
1 PhD Student of Desertification, 2 PhD Student of Soil Science, 3 Professor of Soil
Science, University of Tehran, Iran
Soil salinity is a severe environmental hazard that affects the growth of many crops. It
pronouncedly occurs in arid and semiarid regions and reduces crop production with
different levels. Therefore with correct information and up to date maps about it,
evaluating and monitoring of soil salinity can be conducted. Mapping soil salinity is
difficult due to its large spatial and temporal variability. Remote sensing is widely used
to survey salinity. In the present research 48 surface soil samples representing Yazd-
Ardakan plain were collected and surface soil salinity was measured. Landsat ETM +
data were acquired in 2002. Results showed high correlation between ETM + band 3 and
salt concentration expressed by the exponential equation: y = 0.001e 0.058x and correlation
coefficient R=0.58. Thus, applying this equation to Landsat band 3, a soil salinity map
was prepared. Ten soil samples for investigation of map accuracy were applied. The
obtained soil samples and other ten soil samples which basically had high similarity in
spectral reflectance and geomorphologic characteristics were used to examine the
produced soil salinity map and to assess its accuracy. According to results the produced
soil salinity map had an overall accuracy equal to 87% and Kappa index equal to 47%
indicating an acceptable accuracy for this classification.
Key words: ETM + images, soil salinity, Yazd-Ardakan plain
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