Evaluation and comparison of different geostatistical methods in soil salinity map (Case Study in Miami plain)

Land salinization is a major and destructive problem in the agricultural sector, which must be controlled by proper scientific management. The first step in this way is to identify and map the saline areas. Over the past few decades, the use of geostatistics and remote sensing techniques has been developed to map the soil salinity and monitor its changes. The purpose of this study was to compare the capability of different geostatistics methods to prepare soil surface salinity maps in a part of the Meyami plain, Semnan province. To do this, 225 soil samples were taken from a depth of 0-30 cm of soil from the intersection of regular grid lines of 600 * 600 meters using GPS. EC, pH and clay of soil samples were measured. The results showed that the Kriging method with an average absolute error of 2.29 was more accurate than other interpolation methods and, vice versa, the Spline Thin plate method with an average absolute error of 4.38 had the lowest accuracy. According to the map prepared, the highest, lowest and mean salinity in the Meyami plain were recorded to be 15.69 ds/m, 2.12 ds/m, and, 5.24 ds/m, respectively.