Repository logo

Infoscience

  • English
  • French
Log In
Logo EPFL, École polytechnique fédérale de Lausanne

Infoscience

  • English
  • French
Log In
  1. Home
  2. Academic and Research Output
  3. Conferences, Workshops, Symposiums, and Seminars
  4. Non-stationarity of solute travel time distribution observed in a controlled hydrologic transport volume
 
conference presentation

Non-stationarity of solute travel time distribution observed in a controlled hydrologic transport volume

Queloz, Pierre  
•
Carraro, Luca  
•
Bertuzzo, Enrico  
Show more
2014
American Geophysical Union (AGU), AGU Fall meeting

Experimental data were collected over a year-long period in a transport experiment carried out within a controlled transport volume (represented by a 2m-deep, 1m-diameter lysimeter fitted with bottom drainage). The soil surface was shielded from natural rainfall, replaced by an artificial injection (Poisson process) at the daily timescale. Bottom drainage out-flows were continuously monitored with leakage tipping bucket and evapotranspiration (prompted by a willow tree growing within the system) was measured trough precision load cells, which also allow an accurate and continuous reading of the total water storage. Five artificial soluble tracers (species of fluorobenzoic acid, FBAs, mutually passive) were selected based on low-reactivity and low-retardation in our specific soil and used to individually mark five rainfall inputs of different amplitudes and occurring at various initial soil moisture conditions. Tracer discharge concentration and hydrologic fluxes measurements provide a direct method for the assessment of the bulk effects of transport on the (backward and forward) travel time distributions in the hydrological setting. The large discrepancies observed in terms of mass recovery in the discharge (supported by ex post FBAs quantification in the soil and in the vegetation) and tracer out-fluxes dynamics emphasized the dependence of the forward travel time on the various injection times and the stages experienced by the system during the migration of the pulse. Rescaling the measured travel time distribution by using the cumulative drainage volume as an independent variable instead of the time elapsed since the injection also fails to yield to stationary distributions, as it was argued by Niemi (1997). Our experimental results support earlier theoretical speculations centered on the key role of non-stationarity on the characterization of the properties of hydrologic flow and transport phenomena. A travel time based model, with all in- and out- hydrological fluxes imposed by the experimental measurements, could accurately reproduce the large divergences of the five tracers’ behavior and recovery, using adequate assumptions on the mixing processes occurring within the controlled volume, thus discrediting simple plug-flow (old-water first) and well-mixed processes which fail at this aim.

  • Details
  • Metrics
Type
conference presentation
Author(s)
Queloz, Pierre  
Carraro, Luca  
Bertuzzo, Enrico  
Botter, Gianluca
Rao, P. Suresh C.
Rinaldo, Andrea  
Date Issued

2014

Subjects

hydrologic transport

•

solute transport

•

tracer

•

travel time

•

hydrology

Written at

EPFL

EPFL units
ECHO  
Event nameEvent placeEvent date
American Geophysical Union (AGU), AGU Fall meeting

San Francisco, California, USA

December 15-19, 2014

Available on Infoscience
March 2, 2015
Use this identifier to reference this record
https://infoscience.epfl.ch/handle/20.500.14299/111791
Logo EPFL, École polytechnique fédérale de Lausanne
  • Contact
  • infoscience@epfl.ch

  • Follow us on Facebook
  • Follow us on Instagram
  • Follow us on LinkedIn
  • Follow us on X
  • Follow us on Youtube
AccessibilityLegal noticePrivacy policyCookie settingsEnd User AgreementGet helpFeedback

Infoscience is a service managed and provided by the Library and IT Services of EPFL. © EPFL, tous droits réservés