Home > Research > Publications & Outputs > Primary weathering rates, water transit times, ...

Electronic data

  • WRR-Manuscript-Publication Ready

    Rights statement: An edited version of this paper was published by AGU. Copyright 2017 American Geophysical Union. Ameli, A. A., K. Beven, M. Erlandsson, I. F. Creed, J. J. McDonnell and K. Bishop (2017), Primary weathering rates, water transit times, and concentration-discharge relations: A theoretical analysis for the critical zone, Water Resour. Res., 53, 942–960, doi:10.1002/2016WR019448. To view the published open abstract, go to http://dx.doi.org and enter the DOI.

    Accepted author manuscript, 1.45 MB, PDF document

    Available under license: CC BY-NC: Creative Commons Attribution-NonCommercial 4.0 International License

  • Ameli_et_al-2017-Water_Resources_Research

    Rights statement: C 2016. American Geophysical Union. All Rights Reserved.

    Final published version, 2.39 MB, PDF document

    Available under license: CC BY: Creative Commons Attribution 4.0 International License

Links

Text available via DOI:

View graph of relations

Primary weathering rates, water transit times, and concentration-discharge relations: a theoretical analysis for the critical zone

Research output: Contribution to journalJournal article

Published
  • Ali A. Ameli
  • Keith Beven
  • Martin Erlandsson
  • Irena F. Creed
  • Jeffrey J. McDonnell
  • Kevin Bishop
Close
<mark>Journal publication date</mark>01/2017
<mark>Journal</mark>Water Resources Research
Issue number1
Volume53
Number of pages19
Pages (from-to)942-960
Publication statusPublished
Early online date31/01/17
Original languageEnglish

Abstract

The permeability architecture of the critical zone exerts a major influence on the hydrogeochemistry of the critical zone. Water flow path dynamics drive the spatiotemporal pattern of geochemical evolution and resulting streamflow concentration-discharge (C-Q) relation, but these flow paths are complex and difficult to map quantitatively. Here we couple a new integrated flow and particle tracking transport model with a general reversible Transition State Theory style dissolution rate law to explore theoretically how C-Q relations and concentration in the critical zone respond to decline in saturated hydraulic conductivity (K-s) with soil depth. We do this for a range of flow rates and mineral reaction kinetics. Our results show that for minerals with a high ratio of equilibrium concentration (C-eq) to intrinsic weathering rate (R-max), vertical heterogeneity in K-s enhances the gradient of weathering-derived solute concentration in the critical zone and strengthens the inverse stream C-Q relation. As C-eq/R-max decreases, the spatial distribution of concentration in the critical zone becomes more uniform for a wide range of flow rates, and stream C-Q relation approaches chemostatic behavior, regardless of the degree of vertical heterogeneity in K-s. These findings suggest that the transport-controlled mechanisms in the hillslope can lead to chemostatic C-Q relations in the stream while the hillslope surface reaction-controlled mechanisms are associated with an inverse stream C-Q relation. In addition, as C-eq/R-max decreases, the concentration in the critical zone and stream become less dependent on groundwater age (or transit time).

Bibliographic note

An edited version of this paper was published by AGU. Copyright 2017 American Geophysical Union. Ameli, A. A., K. Beven, M. Erlandsson, I. F. Creed, J. J. McDonnell and K. Bishop (2017), Primary weathering rates, water transit times, and concentration-discharge relations: A theoretical analysis for the critical zone, Water Resour. Res., 53, 942–960, doi:10.1002/2016WR019448. To view the published open abstract, go to http://dx.doi.org and enter the DOI.