Impact of Preferential and Lateral Flows of Water on Single‐Ring Measured Infiltration Process and Its Analysis

Abstract

Core Ideas A special device was developed to visually display the infiltration process. Impacts of preferential and lateral flow on infiltration rates were measured. Mathematical models were derived to correct the measured infiltration rates. The corrected infiltration processes agreed well with the 1D values. To improve the measurement accuracy of the soil infiltration rate, we studied the effects of preferential flow caused by the gap between the soil profile and the ring wall during its installation and lateral flow induced by the three‐dimensional impact of a single ring on the infiltration process. Laboratory experiments using silt loam taken from Beijing were conducted with a device designed to produce a soil profile that could visually display water movement during infiltration in the soil. Observations of the wetted soil profile inside and under the halved ring during the infiltration process were used to partition rates from the soil surface, preferential flow, and lateral movement of water. Mathematical models were derived to correct the measured infiltration rates affected by preferential and lateral flows during the initial and steady infiltration stages. Results indicated that in the initial infiltration stage (0–17 min), the preferential flow significantly increased the measured infiltration rates. Error caused by preferential flow ranged from 207 to 121%. In the following infiltration stage (17–120 min), the contribution of lateral flow ranged from 21 to 77%. Steady infiltration rates estimated with the modified model were 7% higher than those of one‐dimensional infiltration rates, and saturated hydraulic conductivities measured by single ring infiltrometer were 15% higher than rates estimated by the constant head method, which may have been caused by higher static water pressure inside the ring caused by preferential flow passage. This study offers a new analysis of ponded single‐ring infiltrometer data.