To accurate quantify solute transport, determine relevance or develop theory to accurately describe chemical behavior, it is crucial to first quantitatively determine a total solute flux, including preferential flow. A protocol extending a flux method previously developed for tile-drained systems was tested for shallow ground water systems without a tile drain. Bromide was surface broadcast applied around three shallow observation wells and irrigated at 4.1 mm/h. Throughout the study the water table height, soil moisture profiles were continuously monitored along with water flows from pumped observation wells. The bromide flux monitored represented a treated soil area of about 30 m2 per well. Results indicated that: 1) about 98 percent of the applied bromide tracer was recovered; 2) at 4.1 mm/h over half of the surface-applied bromide was recovered at a depth of 1.6 m after only 280 mm of irrigation; and 3) at this location, bromide fluxes were dominated by preferential flow when subjected to a 4.1 mm/h irrigation rate. Preliminary results suggest this protocol may be a useful tool for quantifying solute transport fluxes in non tile-drained systems that contain a shallow groundwater system.
See more of Symposium--Water and Chemical Fluxes from the Pore to Landscape Scale: III
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See more of The ASA-CSSA-SSSA International Annual Meetings (November 6-10, 2005)