TY - JOUR
T1 - Comparing two methods of analysis of single-ring infiltrometer data for a sandy – loam soil
AU - Sgroi, Angelo
AU - Sferlazza, Sebastiano
AU - Bagarello, Vincenzo
PY - 2009
Y1 - 2009
N2 - The single-ring pressure i n filtrometer (PI) with the steady-state Two-Ponding-Depth (TPD) applic ation method were developed to simulta neously determine the saturated soil hydraulic conductivity, K, and the α ⁎ -parameter in the fi eld. Methods of analysis of transient PI data are also available but they have received little testing so far. The transient WU method and the TPD method were compared for a sandy-loam soil. A linearization technique o f the in filtration curve yielded more reliable Kfsfsand α ⁎ results (i.e., falling within expected ranges) than a non-linear optimization technique. The WU method gave both positive and reasonable Kand α ⁎ values for all infi ltration tests. Using the mean soil water content for all tests instead of the locally measu red ones did not affect substantially the calculations because the maximum absolute discrepancy between two estimates of a given variable ( Kfsor α ⁎ ) a t a location wa s equal to 22%. In some cases, the TPD method yielded negative results or excessively low α ⁎ values. The mean results of the TPD method and the WU method with the linearization technique were similar for both Kfsfsand α ⁎ (K: 175.1– 214 .1 m m h− 1; α ⁎ : 3.32 –3.94 m− 1fs). The differences between these two methods were reduced, also in terms of relative variability of the data (coef fi cient of variation = 76.9 – 81.3% for Kand 126.1 –14 9.4% for α ⁎), when locations yielding both positive and reasonable results with the TPD method were considered. It wa s concluded that the WU method is a valid alternative t o the TPD method. The transient method should be preferred especially when time available for the test is limited and flow rates can easily be monitored at short time intervals from the beginning of the test.fs
AB - The single-ring pressure i n filtrometer (PI) with the steady-state Two-Ponding-Depth (TPD) applic ation method were developed to simulta neously determine the saturated soil hydraulic conductivity, K, and the α ⁎ -parameter in the fi eld. Methods of analysis of transient PI data are also available but they have received little testing so far. The transient WU method and the TPD method were compared for a sandy-loam soil. A linearization technique o f the in filtration curve yielded more reliable Kfsfsand α ⁎ results (i.e., falling within expected ranges) than a non-linear optimization technique. The WU method gave both positive and reasonable Kand α ⁎ values for all infi ltration tests. Using the mean soil water content for all tests instead of the locally measu red ones did not affect substantially the calculations because the maximum absolute discrepancy between two estimates of a given variable ( Kfsor α ⁎ ) a t a location wa s equal to 22%. In some cases, the TPD method yielded negative results or excessively low α ⁎ values. The mean results of the TPD method and the WU method with the linearization technique were similar for both Kfsfsand α ⁎ (K: 175.1– 214 .1 m m h− 1; α ⁎ : 3.32 –3.94 m− 1fs). The differences between these two methods were reduced, also in terms of relative variability of the data (coef fi cient of variation = 76.9 – 81.3% for Kand 126.1 –14 9.4% for α ⁎), when locations yielding both positive and reasonable results with the TPD method were considered. It wa s concluded that the WU method is a valid alternative t o the TPD method. The transient method should be preferred especially when time available for the test is limited and flow rates can easily be monitored at short time intervals from the beginning of the test.fs
KW - Measurement techniques Infiltration
KW - Saturated hydraulic conductivity
KW - Single-ring pressure infiltrometer
KW - Measurement techniques Infiltration
KW - Saturated hydraulic conductivity
KW - Single-ring pressure infiltrometer
UR - http://hdl.handle.net/10447/39038
M3 - Article
VL - 149
SP - 415
EP - 420
JO - Geoderma
JF - Geoderma
SN - 0016-7061
ER -