Assessment of Inverse Distance Weighting (IDW) Interpolation on Spatial Variability of Selected Soil Properties in the Cukurova Plain

This study attempts to evaluate interpolation technique for mapping spatial distribution of some soil characteristics at the Lower Seyhan River Basin in Cukurova (Turkey). These soil characteristics may help to improve agricultural land management practices. In the study area, 7 parallel transects each having 150 m of length were selected at 5 m intervals, and 104 soil samples were collected. In these samples, calcium carbonate, organic matter, cation exchange capacity and clay content (from particle size distribution) were determined. Inverse distance weighting (IDW) interpolation and employing of GIS technology were applied on the results. Calcium carbonate, organic matter, cation exchange capacity and clay content values derived from IDW interpolation were consistent with the results of the soil analysis. The verity of the interpolation technique was tested by employing cross validation. Interpolation of organic matter values showed a high mean error in 30-60 cm depth (2.82%) while this high deviation was not the case with the other parameters studied.