Multiphase Reactive Transport Modeling of Seasonal Infiltration Events and Stable Isotope Fractionation in Unsaturated Zone Pore Water and Vapor at the Hanford Site

Singleton, Michael; Sonnenthal, Eric; Conrad, M. E.; DePaolo, Donald J.; Gee, Glendon W.

doi:10.2136/vzj2004.0775

Cited by 47 publications

(28 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Using data from 25 sites across the world, Sprenger, Leistert, Gimbel, and Weiler () revealed that the evaporative fractionation effects were generally limited to the upper 30 cm of the soil, but that effect was climate dependent. Deep progression fronts up to 2–3 m have been reported for sites in arid climates (e.g., Beyer et al, ; Singleton, Sonnenthal, Conrad, DePaolo, & Gee, ), whereas in tropical climates, a clear vertical gradient in the soil water isotopic signal is usually only observed under pronounced dry seasons (Querejeta, Estrada‐Medina, Allen, & Jiménez‐Osornio, ). In tropical regions, the high humidity (Goller et al, ; Good, Noone, & Bowen, ) and typically dense vegetation cover (Dubbert, Cuntz, Piayda, Maguás, & Werner, ) can both contribute to relatively low soil evaporation.…”

Section: Discussionmentioning

confidence: 85%

Depth distribution of soil water sourced by plants at the global scale: A new direct inference approach

et al. 2020

View full text Add to dashboard Cite

The depth distribution of soil water contributions to plant water uptake is poorly known. Here we evaluate the main water sources used by plants at the global scale and the effect of climate and plant groups on water uptake variability and depth distribution. The global meta‐analysis is based on isotope data (δ2H and δ18O) extracted from 65 peer‐reviewed papers published between 1990 and 2017. We applied a new direct inference method to quantify the overlap between xylem water and soil water sources used by plants. The median overlap between xylem water and soil water at different depths varied between 28% and 100%, but they were generally >50%. The shallow (0‐10 cm) soil water overlap with xylem water was largest in cold regions (100% ± 0%) and lowest at tropical sites (about 28%). Conversely, the median overlap between xylem water and deep soil water was largest in the arid and the tropical zones (>75%) and much smaller in the temperate and cold zones. Our results suggest that the isotopic composition of xylem water reflects mostly the signature of shallow soil water (<30 cm) in the cold and the temperate zones, whereas in the arid and the tropical zones, plants appear to exploit water in deeper soil layers. Our novel, simple statistically‐based direct inference method performed well in determining these differences in water sources, and can be applied more widely to isotope‐based plant water uptake studies.

show abstract

Section: Discussionmentioning

confidence: 85%

Depth distribution of soil water sourced by plants at the global scale: A new direct inference approach

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Earlier work of Singleton et al . () used a multiphase reactive transport model (TOUGH‐REACT) and found that the magnitude of the isotopic composition shifts to more depleted values in deep pore waters of the unsaturated zone and is inversely related with the rate of deep infiltration. They were able to illustrate the evolution of the stable isotope profile alternating between wet and dry seasons.…”

Section: Interpretation and Modeling Of Evaporation Profiles In The Umentioning

confidence: 99%

Review on soil water isotope-based groundwater recharge estimations

et al. 2016

View full text Add to dashboard Cite

Groundwater recharge estimations are necessary for sustainable management of groundwater resources. Among various hydraulic, hydrogeological and hydrological approaches, tracer methods are proposed to improve groundwater recharge estimations. Soil water isotope‐based estimates of groundwater recharge rates were developed in the 1960s and have been applied in more than 40 studies reviewed within this manuscript. This comprehensive review research distinguishes three fundamental research approaches: (1) labelling method with tritium or deuterium, which can be used to trace unsaturated zone water movement, (2) tracing soil water movement using a seasonal signal of stable isotopes in precipitation, mainly applied in humid zones, and (3) interpretation of an evaporation signal that impacts soil water stable isotope composition, mainly applicable in arid and semiarid regions. More recently, advances in soil water extraction and analytical methods allow a higher sampling resolution and in situ measurements of soil water stable isotopes. Analytical advances may strengthen and improve the applicability of stable isotope methods for quantitative recharge. We present, compare and discuss studies of unsaturated zone isotope profiles with an emphasis on necessary prerequisites, such as a substantial thick porous sedimentary layer, or negative influences through high clay and silt contents or dry soil conditions. Copyright © 2015 John Wiley & Sons, Ltd.

show abstract

“…[]). Several pore water isotope studies showed that the kinetic fractionation is usually limited to the upper −0.2 to −0.3 m in temperate regions [e.g., Komor and Emerson , ; Gazis and Feng , ; Zhang et al ., ; Sutanto et al ., ], increases to 0.5 m in Mediterranean climates [ Simonin et al ., ; Oshun et al ., ], and can reach down to −3 m in arid climates [ Allison and Hughes , ; Singleton et al ., ]. Figure supports these findings, where we present the lc‐excess over the depth.…”

Section: Atmospheric Influencesmentioning

confidence: 99%

Illuminating hydrological processes at the soil‐vegetation‐atmosphere interface with water stable isotopes

Sprenger

Leistert

Gimbel

et al. 2016

Reviews of Geophysics

437

382

View full text Add to dashboard Cite

Water stable isotopes (18O and 2H) are widely used as ideal tracers to track water through the soil and to separate evaporation from transpiration. Due to the technical developments in the last two decades, soil water stable isotope data have become easier to collect. Thus, the application of isotope methods in soils is growing rapidly. Studies that make use of soil water stable isotopes often have a multidisciplinary character since an interplay of processes that take place in the vadose zone has to be considered. In this review, we provide an overview of the hydrological processes that alter the soil water stable isotopic composition and present studies utilizing pore water stable isotopes. The processes that are discussed include the water input as precipitation or throughfall, the output as evaporation, transpiration, or recharge, and specific flow and transport processes. Based on the review and supported by additional data and modeling results, we pose a different view on the recently proposed two water world hypothesis. As an alternative to two distinct pools of soil water, where one pool is enriched in heavy isotopes and used by the vegetation and the other pool does not undergo isotopic fractionation and becomes recharge, the water gets successively mixed with newly introduced rainwater during the percolation process. This way, water initially isotopically enriched in the topsoil loses the fractionation signal with increasing infiltration depth, leading to unfractionated isotopic signals in the groundwater.

show abstract

Multiphase Reactive Transport Modeling of Seasonal Infiltration Events and Stable Isotope Fractionation in Unsaturated Zone Pore Water and Vapor at the Hanford Site

Cited by 47 publications

References 37 publications

Depth distribution of soil water sourced by plants at the global scale: A new direct inference approach

Depth distribution of soil water sourced by plants at the global scale: A new direct inference approach

Review on soil water isotope-based groundwater recharge estimations

Illuminating hydrological processes at the soil‐vegetation‐atmosphere interface with water stable isotopes

Contact Info

Product

Resources

About