Premium
Numerical Evaluation of Depth Effects of Double‐Ring Infiltrometers on Soil Saturated Hydraulic Conductivity Measurements
Author(s) -
Lai Jianbin,
Luo Yi,
Ren Li
Publication year - 2012
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2011.0048
Subject(s) - infiltrometer , hydraulic conductivity , ring (chemistry) , soil science , geometry , mathematics , chemistry , geology , soil water , organic chemistry
Previous research has indicated that the measurements of soil saturated hydraulic conductivity ( K s ) are influenced by both the radial size and depth of a double‐ring infiltrometer. Few studies are available, however, on how the depth to which an infiltrometer is driven affects K s measurement. In this study, six inner ring depths ( d i = 5, 10, 15, 25, 40, and 60 cm), six outer ring depths ( d o = 5, 10, 15, 25, 40, and 60 cm), and their combinations were designed. Thus 24 sets of driven depths of infiltrometer were involved. For each infiltrometer set, 31 stochastic fields of K s were randomly generated in the simulation domain by adopting six correlation lengths ( L = 0, 10, 20, 50, 100, and 200 cm) and six standard deviations (SD = 0, 0.1, 0.25, 0.5, 0.75, and 1.0). Therefore, a total of 7224 simulations were conducted to investigate the driven‐depth effect of the double‐ring infiltrometer on the measurements of soil saturated hydraulic conductivity of the wetted zone ( K w ). Results demonstrated that the inner ring depth plays a more important role than the outer ring depth in K w measurements by double‐ring infiltrometer, and increasing the inner ring depth could obtain a better approximation of accurate K w measurements. Meanwhile, the outer ring added to a single‐ring infiltrometer was necessary in guaranteeing vertical water flow in the inner ring and improving measurement accuracy. Considering that the disturbance of soil caused by ring installation will increase with increasing ring depth, the ring depth of 5 to 15 cm that has been adopted in most ring‐infiltrometer‐related field experiments is acceptable and recommended for K w measurements.