Virginia Tech
Quantifying Solute and Water Fluxes in Headwater Streams Using Passive Flux Meters
Abstract
dc:description.abstractPassive samplers can be used to determine time-integrated patterns of water chemistry at one or many locations throughout a stream network while minimizing cost and sampling time. A passive flux meter (PFM) simultaneously estimates time-averaged water and solute mass fluxes in flowing water. PFMs have been used in groundwater to quantify contaminant flux but have been used only very recently in streams. In this study, PFMs were deployed in the surface and subsurface of headwater stream channels to examine the efficacy of the device to quantify mean concentrations of calcium, aluminum, and sulfur in streams of the Hubbard Brook Experimental Forest in New Hampshire, USA. In general, the PFM estimates of surface and subsurface stream chemistry were more accurate when flow rates were higher and more water passed through the PFM. During the lowest flows, PFMs overpredicted concentrations by 50 to 800%. In estimating calcium concentrations, 5 PFMs were within 10% of grab sample concentrations and 7 PFMs were within 30% of grab sample concentrations out of a total of 35 comparisons. Likewise, for sulfur concentrations, 4 PFMs were within 10% of grab sample concentrations and 7 PFMs were within 30% of grab sample concentrations out of 35 comparisons. Concentrations of aluminum were too low to be quantified above 90% confidence. PFMs calculated a lower cumulative discharge through the surface water PFMs than through the subsurface which may be explained by flow divergence around the sampler. Changes to PFM design and shorter deployment times are proposed to increase the efficacy of the PFM.
Degree
thesis:*- Name thesis:degree_name
- Master of Science
- Level thesis:degree_level
- masters
- Discipline thesis:degree_discipline
- Forestry
- Department dc:contributor.department
- Forest Resources and Environmental Conservation
- Grantor dc:publisher
- Virginia Tech
- Year dc:date.issued
- 2018
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Lee, David Parrish
- Chair dc:contributor.committeechair
-
- McGuire, Kevin J.
- Committee members dc:contributor.committeemember
-
- Strahm, Brian D.
- McLaughlin, Daniel L.
Subjects
dc:subject × 5Rights
dc:rights- Statement dc:rights
-
- In Copyright
- Licence dc:rights.uri
Identifiers
dc:identifier.*- Dc Identifier Other
- vt_gsexam:15843
- OAI identifier oai:identifier
- oai:vtechworks.lib.vt.edu:10919/83784