Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/3/2014
Publication Date: 11/2/2014
Citation: Chagas, I., Huang, C., Bowling, L., Smith, D.R. 2014. Assessment of electrical conductivity as a surrogate measurement for water samples in a tracer injection experiment [abstract]. American Society of Agronomy Annual Meeting, November 2-5, 2014, Long Beach, CA. 2014 CDROM.
Technical Abstract: The transport behavior of solutes in streams depends on chemical, physical, biological, and hydrodynamic processes. Although it is a very complex system, it is known that this behavior is greatly influenced by surface and subsurface flows. For this reason, tracer injection in the water flows is one of the most extensively used approaches to evaluate the solute transport in flumes or streams. It yields results in terms of total mass or solutes concentration by collection of water samples at different locations and its dynamic is assessed by using transient storage models. Electrical conductivity (EC) measurements have been used to quantify the tracer breakthrough. Since EC data can be obtained automatically at high frequency, we are interested in knowing whether EC readings can be used as surrogates for analyzed chemical concentrations from collected water samples, because water sample collection and the subsequent analytic work are time consuming and laborious. An injection study was conducted in a 20-m flume under seepage, saturation and drainage conditions. The flume was filled with sediments collected from a drainage ditch. Bromide and phosphate solutions were injected in order to monitor their movement along the flume. EC was measured at five different locations along the flume. Water samples were collected every minute and analyzed for bromide and phosphorus. In this presentation, we will discuss the potential advantages and issues with using easily obtained EC data as a surrogate for phosphorus and bromide transport in surface flow.