Monitoring of Soil Salinity in Land Destruction Using Remote Sensing Techniques (Ilam Province Case Study)

Soil salinization is one of the dominant processes of land degradation in arid and semi-arid regions.  Soil salinity is one of the most important problems affecting many parts of the world. Salty soils in agricultural areas reduce the annual crop yield of most crops. As a first step, soil sampling and Landsat images are pre-processed. Different salinity indices such as NDSI (normalized salinity index), BI (brightness index) and SI (salinity index) were used to map the salinity of the study area. As well as Laboratory measurements of electrical conductivity (EC) and soil acidity (pH) have also been performed. In this regard, the values of three salinity indices NDSI, BI, SI for 2017, 2015, 2010, 2005, and 2000 were calculated in ENVI and GIS software. Based on the results of satellite imagery analysis, saline soils in the west and southwest of Ilam province (sub-basins of Mehran, Musian-Abdanan, Abbas-west-east and Molab basins) are located. According to field surveys and soil sampling for different areas of Ilam province, it was found that pH values below Mehran basin, south Dehloran and downstream of Simareh Dam are above 8.5 and indicate alkaline and sodium soils. And other examples show unusual, up to slightly salted soil. This means that the results of the remote sensing analyzs partially confirm the data obtained from estimating soil EC and pH values in the study area.