Soil salinity mapping by different interpolation methods in Mirzaabad district, Syrdarya Province

Abstract

Abstract Soil salinity is an important global issue and especially on irrigated areas due to its great impact on a crop production system. Proper soil salinity mapping can improve land use management. The goal of this study was to improve the accuracy of soil salinity mapping with the two objectives (1) to evaluate different interpolation methods during soil salinity mapping and (2) to identify of differences in soil salinity assessments in irrigated land of Mirzaabad district which is most affected by salinity in Syrdarya province of Uzbekistan. Soil salinity data measured by EC meter was obtained from Syrdarya Hydromelioration Expedition. Different four interpolation methods such as Inverse Distance Weighted (IDW) with power 1, 2, and 3, and Kriging techniques were used for the generation continuous surface of soil salinity maps. The cross-Validation method with the assessment of Root Mean Square Errors (RMSE) shows that IDW with power 2 (IDW-2) most accurate. The maximum difference reached between IDW-2 and IDW-1 on the slightly saline area where the value decreased by 55% of the total irrigated land of the district. Minimum differences reached on IDW-3 on moderated saline class and higher than IDW-2 on 408.6 ha.