ORIGINAL RESEARCH
Monitoring Soil Salinity Changes, Comparison
of Different Maps and Indices Extracted
from Landsat Satellite Images
(Case Study: Atabieh, Khuzestan)
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1
Department of Soil Sciences, Khuzestan Science and Research Branch, Islamic Azad University, Ahvaz, Iran
2
Department of Soil Sciences, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran
3
Department of Geology, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran
Submission date: 2020-02-18
Final revision date: 2020-05-29
Acceptance date: 2020-06-03
Online publication date: 2020-10-16
Publication date: 2021-01-20
Corresponding author
Ahad Nazarpour
Department of Geology, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran, Iran
Pol. J. Environ. Stud. 2021;30(2):1139-1154
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ABSTRACT
Soil salinity is the dominant process in the degradation of arid and semi-arid soils, which in turn
reduces crop yields, increases erosion, and exacerbates desertification. In recent years, soil salinity has
affected much of the land in the Atabieh area located in the west of Khuzestan province in Iran. The
purpose of this study was thus to evaluate and map soil salinity changes in the region over 15 years
using Landsat 7 and 8 satellite images. To that end, the spectra of saline soils in the study area were
extracted from the satellite data, and after the initial pre-processing in EVNI software version 5.3, the
SI1, SI2, SI3, BI, NDVI, and NDSI indices were prepared. Using the supervised classification method,
the salinity map with four different classes was then plotted in Arc GIS version 10.2, and the changes in
saline soil area were investigated. Moreover, field surveys, surface soil sampling, soil EC measurement
and identification of available minerals were performed by X-ray diffraction (XRD) technique and
satellite images. Among the studied indices, the BI index with the highest correlation (0.71) was
considered as the best index, and NDVI with the correlation coefficient of 0.35 at the 95% confidence
level, was the best index for vegetation cover. Examination of changes in BI index by Landsat 7 images
showed that the non-saline land area decreased from 1023.54 ha in 2000 to 143.43 ha in 2010, while the
area with medium salinity increased by 14.57%. Besides, the salinity severity in the NDVI index had
a growth rate of 72.86%. In turn, XRD studies confirmed the presence of abundant evaporate minerals
(Halites, Calcite and Dolomite) corresponding to the values (real numbers) of salinity and mineralogical
maps obtained from the Landsat 8 images.