Introducing a simple method for calculating hydraulic parameters by Beerkan infiltration experiment

The Beerkan single ring infiltration experiment is receiving more attention because of its simplicity and low expense in running in recent years. BESTslope algorithm is the original algorithm in Beerkan experiment, which estimates some soil hydraulic properties such as saturated hydraulic conductivity (Ks) and sorptivity coefficient (S).The purpose of this research is to compare the performance of BESTslope algorithm with a simple proposed method and to determine the value of a constant parameter as the ratio of gravity force to capillary force (α) for loam and sandy loam soils. For this purpose, a number of 113 beerkan infiltration experiments were carried out in Sistan research field. The results showed that the estimated Ks values for 31 selected experiments, in which the relative fitting error (Er) for each test is less than 5.5% are similar to those obtained for 59 selected experiments having an average Er of less than 5.5%. However, these results were largely different from those obtained for 101 selected experiments having an average Er of less than 10%. Overall, the magnitude of α for loam and sandy loam soils of study area was determined as the average of two α values obtained for 31 and 59 selected experiments and it is equal to 0.013.