𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Evaluating the effect of using artificial pore water on the quality of laboratory hydraulic conductivity measurements of peat

✍ Scribed by Nicholas Kettridge; Andrew Binley

Publisher
John Wiley and Sons
Year
2010
Tongue
English
Weight
322 KB
Volume
24
Category
Article
ISSN
0885-6087

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

Pore dilation, the compaction of humic acids on peat fibres due to the process of flocculation, causes the hydraulic conductivity of peat to increase with increasing pore water electrical conductivity. This is a reversible process and a reduction in the pore water conductivity produces a decrease in the hydraulic conductivity due to the constriction of pores. We verify how this dilation and constriction of pores, resulting from the application of artificial pore water (primarily deionized water), affects laboratory measurements of the hydraulic conductivity of peat. Repeat measurements of the hydraulic conductivity were performed on samples of Sphagnum peat. It is shown that the application of deionized water during constant head permeameter tests causes a significant decrease in the hydraulic conductivity. Between tests, the hydraulic conductivity of the peat continues to decline without an associate decrease in the pore water electrical conductivity because of a lagged pore constriction effect. We suggest that the use of artificially high or low pore water electrical conductivities, during laboratory hydraulic conductivity measurements, is likely to lead to significant errors. Experimental protocols must, therefore, be revised to take better account of the pore water chemistry. The ionic concentrations of the natural pore fluid should be replicated during hydraulic conductivity tests, either by using pore fluid extracted from the study site or by artificially replicating the major ionic composition of the natural pore fluid. In addition, prior to the hydraulic conductivity measurements, peat samples should be flushed with this solution until the hydraulic conductivity stabilizes and the samples subsequently allowed to equilibrate. Copyright Β© 2010 John Wiley & Sons, Ltd.

πŸ“œ SIMILAR VOLUMES

Evaluating the quality of hydraulic cond
Evaluating the quality of hydraulic conductivity estimates from piezometer slug tests in peat
✍ Ben W. J. Surridge; Dr Andrew J. Baird; A. L. Heathwaite πŸ“‚ Article πŸ“… 2005 πŸ› John Wiley and Sons 🌐 English βš– 315 KB

## Abstract Although widely used in wetland hydrological studies, hydraulic conductivity (__K__) estimates from piezometer slug tests are often of questionable validity. Frequently, this is because insufficient attention is paid to the details of the test procedure. Further, in a potentially hetero

Anisotropy and depth-related heterogenei
Anisotropy and depth-related heterogeneity of hydraulic conductivity in a bog peat. II: modelling the effects on groundwater flow
✍ Clive W. Beckwith; Andrew J. Baird; A. Louise Heathwaite πŸ“‚ Article πŸ“… 2002 πŸ› John Wiley and Sons 🌐 English βš– 195 KB πŸ‘ 2 views

## Abstract Anisotropy and heterogeneity of hydraulic conductivity (__K__) are seldom considered in models of mire hydrology. We investigated the effect of anisotropy and heterogeneity on groundwater flow in bog peat using a steady‐state groundwater model. In five model simulations, four sets of __

Synergistic effects of water repellency
Synergistic effects of water repellency and macropore flow on the hydraulic conductivity of a burned forest soil, south-east Australia
✍ Petter Nyman; Gary Sheridan; Patrick N. J. Lane πŸ“‚ Article πŸ“… 2010 πŸ› John Wiley and Sons 🌐 English βš– 477 KB

## Abstract Research shows that water repellency is a key hydraulic property that results in reduced infiltration rates in burned soils. However, more work is required in order to link the hydrological behaviour of water repellent soils to observed runoff responses at the plot and hillslope scale.