Assessing the Size Dependency of Measured Hydraulic Conductivity Using Double-Ring Infiltrometers and Numerical Simulation
- Jianbin Lai and
- Li Ren *
Saturated hydraulic conductivity measurements are important for understanding and modeling hydrologic processes at the field scale. Few systematic studies have been conducted on how the size of double-ring infiltrometers affects the measured hydraulic conductivity. To determine this size effect, we measured saturated hydraulic conductivity at seven sites using four different sizes of double-ring infiltrometers. Inner-ring diameters, d i, were 20, 40, 80, and 120 cm. Detailed numerical investigations were also conducted to explain how the inner-ring size of a double-ring infiltrometer influences the measured hydraulic conductivity in a heterogeneous soil. Field and simulation results both demonstrated that the variability in measured hydraulic conductivity was greater for smaller inner rings (e.g., d i <40 cm), and gradually decreased as the ring size increased. Our study indicates that where soil spatial variability is high, infiltrometers having a large inner ring (in general, d i >80 cm) are essential for reliable measurement.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © 2007.