Evaluation Of The Aardvark Constant Head Soil Permeameter To Predict Saturated Hydraulic Conductivity
Free (open access)
153 - 162
E. Theron, P. A. L. Le Roux, M. Hensley & L. Van Rensburg
The saturated hydraulic conductivity (Ksat) is a key parameter for analyzing or modelling water flow and chemical transport in subsurface soil. Several methods were developed over the last thirty years to measure Ksat which considered unsaturated and/or saturated flow of water around the holes where measurements are made. Most methods make use of devices to measure the infiltration rate into the soil and in combination with numerical models predict the Ksat parameter. If maximum infiltration rate exceeds the infiltration capacity, runoff will be the consequence. Therefore maintaining a constant head means the rate of water supplied corresponds to the infiltration capacity. Commonly used devices for infiltration capacity measurements are infiltrometers, disc permeameters, sprinkler infiltrometers and different types of constant head permeameters. This paper evaluates the theory and practical application of the Aardvark constant head soil permeameter (ACHSP) in combination with the Glover equation for field measurement of Ksat above the water table. The Glover equation has been criticized during the eighties because only the saturated flow around the hole was considered in its development. Several papers published since 2002, however, demonstrated that the Glover equation results are relatively close to the results obtained by other models for most practical applications and therefore the use of the Glover equation is justified. Keywords: saturated hydraulic conductivity, constant head permeameter, Glover equation, double ring infiltrometer.
saturated hydraulic conductivity, constant head permeameter, Glover equation, double ring infiltrometer