Abstract
The objective of this study was to modify a ring infiltrometer and to develop a simple and generic technique for simulating cumulative infiltration under constant on‐time surge cycles. A ring infiltrometer was modified by connecting a pipe arm for inward and outward water flow to the ring and from the ring to the pipe to create on–off surge cycles respectively. The Kostiakov infiltration equation was modified by introducing“surge factors” to simulate infiltration data for subsequent surges, using first surge infiltrometer data. The modified form of the Kostiakov equation is called the, “Azeemi–Kostiakov equation”. The unknown parameters of the Kostiakov equation were determined by applying the two‐point technique. Results of the study revealed that the infiltration data simulated by the Azeemi–Kostiakov equation matched closely with those collected from the surge‐ring infiltrometer. A significant reduction in the cumulative infiltration during different surges was also observed which varies from 61 to 84% for the first surge and from 30 to 61% for the subsequent surges. On an overall basis, the significant advantage of the Azeemi–Kostiakov equation is its application in simulating cumulative infiltration of subsequent surges by successfully using limited infiltrometer data. The validity of the Azeemi–Kostiakov equation outside the conditions of the experiments and for varying on–off surge cycles needs to be verified in order to extend its applicability. If this is done, the prior estimation of infiltration for a desired set of on–off surge cycles through this method would permit planning of surge irrigation studies for efficient water management. Copyright © 2005 John Wiley & Sons, Ltd.