Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


20992.pdf (2.71 MB)

ETD Abstract Container

Abstract Header

Towards Understanding Dissolved Organic Carbon Dynamics at the Intersection of Anthropogenic Modifications and Natural Processes of a Dryland River

Wise, Julia L
http://orcid.org/0000-0002-7302-8421
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1470753635

Abstract Details

2016, PhD, University of Cincinnati, Arts and Sciences: Geology.
Dissolved organic carbon (DOC) is a critical nutrient in aquatic ecosystems, but can also be a pollutant in drinking water. Controlled by a combination of catchment wide and instream processes, the bioavailability, reactivity, and concentration of DOC is readily altered by natural and anthropogenic processes within rivers and the greater watershed area. However, little is known about natural or anthropogenic controls on DOC in dryland areas where water resources are limited and increasingly endangered. To address this, we examined the major contributors of DOC within and to a dryland river—the Middle Rio Grande (MRG) in central New Mexico. This was achieved via synoptic sampling of storm event flow in an urban storm drainage system, water in agricultural conveyances, and monthly sampling of the mainstem. We measured DOC concentration, determined its source (terrestrial or instream), and explored its chemical structure (aliphatic v. aromatic) as an indicator of lability. We found that during storm events, DOC entering the river from the storm drainage system is derived from a combination of terrestrial and instream sources. The connection of the landscape to the river via storm event runoff controls when during the storm event DOC from these two sources reaches the river. We found that the agricultural system is a net DOC sink because of water loss during irrigation. The agricultural irrigation system also acts a biogeochemical hotspot where DOC is rapidly cycled. As a result labile DOC is introduced in the agricultural system’s conveyances and DOC effluent from the agricultural systems is more labile and bioavailable than DOC in the mainstem. Within the Middle Rio Grande, we find that despite the addition of DOC from storms and agricultural systems, DOC concentration and character remains largely consistent over time and as the river moves north to south. Additionally, in the MRG DOC concentration is uncoupled from discharge. Thus, we hypothesize that anthropogenic modifications of the watershed and river increase the amount of labile DOC and drive DOC concentration, overriding the influence of natural processes such as discharge. The results of this dissertation provide a framework to understand the competing influences of natural processes and anthropogenic alteration on DOC concentration, source, and character. This framework can guide future research in water treatment and reuse and nutrient dynamics in dryland regions.
Aaron Diefendorf, Ph.D. (Committee Chair)
Thomas Lowell, Ph.D. (Committee Member)
J Barry Maynard, Ph.D. (Committee Member)
David Byer Nash, Ph.D. (Committee Member)
Jodi Shann, Ph.D. (Committee Member)
112 p.
Geochemistry
Dissolved Organic Carbon; Storm Event; Agriculture; Dryland River; Middle Rio Grande; Nutrient Dynamics

Recommended Citations

Citations

  • Wise, J. L. (2016). Towards Understanding Dissolved Organic Carbon Dynamics at the Intersection of Anthropogenic Modifications and Natural Processes of a Dryland River [Doctoral dissertation, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1470753635

    APA Style (7th edition)

  • Wise, Julia. Towards Understanding Dissolved Organic Carbon Dynamics at the Intersection of Anthropogenic Modifications and Natural Processes of a Dryland River. 2016. University of Cincinnati, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1470753635.

    MLA Style (8th edition)

  • Wise, Julia. "Towards Understanding Dissolved Organic Carbon Dynamics at the Intersection of Anthropogenic Modifications and Natural Processes of a Dryland River." Doctoral dissertation, University of Cincinnati, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1470753635

    Chicago Manual of Style (17th edition)

ucin1470753635
210
© 2016, some rights reserved.Creative Commons License Towards Understanding Dissolved Organic Carbon Dynamics at the Intersection of Anthropogenic Modifications and Natural Processes of a Dryland River by Julia L Wise is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by University of Cincinnati and OhioLINK.
Release 3.2.12