Electrical resistivity measurements for spatial soil moisture variability estimation

This experimental work empirically compares the results obtained in soil moisture spatial estimation performed with different interpolation techniques. Three algorithms were compared: Inverse Distance Weight (IDW), Ordinary Kriging (OK) and Co-Kriging (CoK). The data used were obtained through an in-situ sampling in a test site located in central Italy. The calibration and the validation data set contain respectively 40 and 133 point measurements of TDR soil moisture. The covariate used is a data set of 533 electrical resistivity (conductivity) point measurements. In terms of prediction accuracy results show no great differences between the performance of the IDW and the OK methods. Quite more accurate results were obtained incorporating the secondary variable information in the CoK algorithm.