Comparison of soil water infiltration using single and double ring methods

Initial soil moisture content has an important role in soil water infiltration, therefore the values of infiltration and the coefficients of infiltration models are not similar in different initial soil moisture content. Single and double ring methods can be used for infiltration measurement. In this study, 24 infiltration experiments were used based on single and double ring methods in different initial soil moisture content to evaluate the values of cumulative infiltration and infiltration rate. The experiment was done on a soil sample with silty clay loam texture, and the model of Kostiakov was used for fitting the measured infiltration data. Also, the coefficients of the Kostiakov model were determined for all single and double ring experiments, and then the relationships were derived between the coefficients of the Kostiakov model and initial soil moisture content. Furthermore, the relationships were derived between infiltration rate in 180 minute and initial soil moisture content, and between cumulative infiltration with double ring method based on single ring method. For these purposes, 17 experiments were used for calibrating the relationships and the other remained 7 experiments were used for validating the results. The results showed that the values of cumulative infiltration and infiltration rate were higher in all 24 experiments with single ring method than double ring method. Also, the results demonstrated that the obtained relationships for estimating the cumulative infiltration with double ring method based on single ring method are appropriate