| Abstrakt: |
qdOne of the most important limitations of cultivation in the Sistan plain is soil salinity. To investigate the salinity status using remote sensing in Sistan Plain, Landsat 8 (LC08- LOI/TIRS) satellite images were used in April, August and November of 2017 and April 2018. To convert radiance data, the initial correction related to voltage change to digital number (DN) to convert radiance data was done by sensor calibration file as well as data radiometric correction using flat area method in ENVI 5.1 software. To determine the soil sampling points, first draw a 2x2 km grid and then by referring to the area and checking the sampling location, 312 soil samples were taken and the values of Electrical Conductivity (EC), Sodium Adsorption ratio (SAR) and texture in them were measured. By secondary processing, extracting the spectral features of satellite images and using several algorithms and indices, a salinity map was prepared for the surface soils of the region in four periods. The results of the remote sensing investigation showed that surface soil salinity in the region is a dynamic phenomenon and has significant changes with the changes of season, rainfall, irrigation and land management. The results obtained from the interpretation of satellite images showed that time, rainfall events of the planting season and water and soil management have a significant effect on soil salinity and the areas of lands with different salinity. The extent of soils with high salinity increased in the summer season, but in April 2018 (MBE=0.98, NRMSE=17.56%, R²=0.69) which coincided with the sampling due to the occurrence of rains and floods in these areas, this extent decreased. [ABSTRACT FROM AUTHOR] |
