| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
ABSTRACT
The flux of water in unsaturated soils can be determined indirectly by using Darcy's Law. The critical part of this approach is the determination of the hydraulic conductivity at a given depth and time. In this paper we analyze the relative errors of hydraulic conductivities determined from a transient drainage field experiment. Knowing the errors of this method would be useful in planning future experiments. It allows putting limitations on the conclusions to be drawn from such experiments and it further allows re-examination of already published field data.
In the wet range of the conductivity function errors are 20–30% of the k-value. In the range where k-values are small, the relative errors may be > 100%. Errors stemming from tensiometer readings are significant when the hydraulic gradient is < 0.3 mbar · cm-1. During the early stage of the transient drainage experiment these errors are always considerable and are more important than other errors. On the other hand, the errors in the measured water content changes are dominant when drainage is slowed down due to desaturation of the soil.
The errors contained in the conductivity, k, are calculated by means of error propagation equations. These errors are also simulated using the Monte Carlo technique. The simulation shows that the conductivity errors predicted by explicit error propagation equations are optimistic minimum estimates.
1 This paper is part of a cooperative investigation between the Univ. of California, Riverside and Berkeley, made at the Kearney Hort. Field Stn., Parlier, California. Supported in part by the National Science Foundation Grant no. GI 34733X. The senior author was supported by the Swiss National Science Foundation.
2 Assistant Research Soil Physicist, Univ. of California, Riverside; Assistant Research Soil Chemist, Univ. of California, Berkeley; and Professor of Soil Physics, Univ. of California, Riverside, respectively.
Received for publication February 16, 1976. Accepted for publication June 29, 1976.
This article has been cited by other articles:
|
|
 |
|
  E. Segal, S. A. Bradford, P. Shouse, N. Lazarovitch, and D. Corwin Integration of Hard and Soft Data to Characterize Field-Scale Hydraulic Properties for Flow and Transport Studies Vadose Zone J., August 1, 2008; 7(3): 878 - 889. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Basile, A. Coppola, R. De Mascellis, and L. Randazzo Scaling Approach to Deduce Field Unsaturated Hydraulic Properties and Behavior from Laboratory Measurements on Small Cores Vadose Zone J., August 24, 2006; 5(3): 1005 - 1016. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Spohrer, L. Herrmann, J. Ingwersen, and K. Stahr Applicability of Uni- and Bimodal Retention Functions for Water Flow Modeling in a Tropical Acrisol Vadose Zone J., December 16, 2005; 5(1): 48 - 58. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Mori, J. W. Hopmans, A. P. Mortensen, and G. J. Kluitenberg Estimation of Vadose Zone Water Flux from Multi-Functional Heat Pulse Probe Measurements Soil Sci. Soc. Am. J., April 11, 2005; 69(3): 599 - 606. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Z. F. Zhang, Z. F. Zhang, A. L. Ward, and G. W. Gee Estimating Soil Hydraulic Parameters of a Field Drainage Experiment Using Inverse Techniques Vadose Zone J., May 1, 2003; 2(2): 201 - 211. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Bruckler, P. Bertuzzi, R. Angulo-Jaramillo, and S. Ruy Testing an Infiltration Method for Estimating Soil Hydraulic Properties in the Laboratory Soil Sci. Soc. Am. J., March 1, 2002; 66(2): 384 - 395. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| The SCI Journals | Agronomy Journal | Crop Science | |||
| Journal of Natural Resources and Life Sciences Education |
Vadose Zone Journal | ||||
| Journal of Plant Registrations | Journal of Environmental Quality |
The Plant Genome | |||
