Transport of bromide in the Bainsvlei soil: Field experiment and deterministic/stochastic model simulation. I. Continuous water application

Ketema (Tilahun) Zeleke, Joseph Botha, Alan Bennie

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

A field-scale tracer study was carried out in a sandy loam Bainsvlei soil of South Africa. The objectives were to study the leaching of solutes in this soil and analyse the result using deterministic and stochastic solute transport models. A rainfall simulator was used to apply water and solution on an area 100 by 100 cm at a flux rate of 5.41 mm/h. A neutron probe access tube was drilled at the centre of the plot to a depth of 200 cm. Four tensiometers were installed at 30, 45, 90, and 120 cm depths. After steady-state condition was attained, a conservative tracer Br' was then applied as KBr at a rate of 13.5 g Br/m2. Soil samples were taken 10 times at 20-cm depth intervals to a depth of 160 cm and Br' concentration was analysed using ion chromatography. Transport parameters were determined using a convection'dispersion equation (CDE) and the stream tube model (STM).The average Br' mass recovery was almost 100%. The average pore-water velocity determined from soil water balance was 2.08 cm/h. Pore-water velocities determined with CDE and STM were 2.24 cm/h and 2.20 cm/h, respectively. Bromide velocities of peak concentration and solute centre of mass were 2.05 cm/h and 2.02 cm/h, respectively. Generally, these results indicate that the Br' moved almost as a piston flow in this soil. The deterministic CDE and the stochastic STM performed almost equally well in estimating the transport parameters.
Original languageEnglish
Pages (from-to)73-80
Number of pages8
JournalSoil Research
Volume43
Issue number1
DOIs
Publication statusPublished - 2005

Fingerprint

Dive into the research topics of 'Transport of bromide in the Bainsvlei soil: Field experiment and deterministic/stochastic model simulation. I. Continuous water application'. Together they form a unique fingerprint.

Cite this