Comparison of the stable-isotopic composition of soil water collected from suction lysimeters, wick samplers, and cores in a sandy unsaturated zone

Landon, Matthew K.; Delin, G.N.; Komor, Stephen C.; Regan, Charles

doi:10.1016/s0022-1694(99)00120-1

Cited by 98 publications

(92 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…One should note that the VSPs at the margins yielded pore-water samples mainly following intense rain events, which led to deep rainwater infiltration and increased the water content of the clay sediment (> 0.35 m 3 m −3 ) (Baram et al, 2012a). This relationship between the ability to sample pore water from the relatively dry clay sediments and the deep infiltration of rainwater, along with the observation made by Landon et al (1999) on the higher proportion of more mobile water (15-95 %) in suction lysimeter samples compared with samples from sediment cores (5-80 %) at the same depth, can explain the consistently lighter composition of the "mobile" pore-water samples compared to the clay matrix water samples. These differences, along with the depleted δ 18 O values observed in sediment of the vadose zone (5.5 and 7.2 m under the background plot and 5-6 m under the pond margins, Fig.…”

Section: Vadose Zone Under the Waste Pond Areamentioning

confidence: 57%

Desiccation-crack-induced salinization in deep clay sediment

Baram

Ronen

Kurtzman

et al. 2013

Hydrol. Earth Syst. Sci.

View full text Add to dashboard Cite

Abstract.A study on water infiltration and solute transport in a clayey vadose zone underlying a dairy farm waste source was conducted to assess the impact of desiccation cracks on subsurface evaporation and salinization. The study is based on five years of continuous measurements of the temporal variation in the vadose zone water content and on the chemical and isotopic composition of the sediment and pore water in it. The isotopic composition of water stable isotopes (δ 18 O and δ 2 H) in water and sediment samples, from the area where desiccation crack networks prevail, indicated subsurface evaporation down to ∼ 3.5 m below land surface, and vertical and lateral preferential transport of water, following erratic preferential infiltration events. Chloride (Cl − ) concentrations in the vadose zone pore water substantially increased with depth, evidence of deep subsurface evaporation and down flushing of concentrated solutions from the evaporation zones during preferential infiltration events. These observations led to development of a desiccation-crack-induced salinization (DCIS) conceptual model. DCIS suggests that thermally driven convective air flow in the desiccation cracks induces evaporation and salinization in relatively deep sections of the subsurface. This conceptual model supports previous conceptual models on vadose zone and groundwater salinization in fractured rock in arid environments and extends its validity to clayey soils in semi-arid environments.

show abstract

Section: Vadose Zone Under the Waste Pond Areamentioning

confidence: 57%

Desiccation-crack-induced salinization in deep clay sediment

Baram

Ronen

Kurtzman

et al. 2013

Hydrol. Earth Syst. Sci.

View full text Add to dashboard Cite

show abstract

“…The wick samplers were constructed of fiberglass attached to a glass plate, based on the design of Brown et al (1986). Results from previous field tests indicated that water collected from the wick samplers had larger concentrations and was more representative of mobile soil water that recharged ground water during or soon after a recharge event than soil water from the suction lysimeters (Landon et al, 1999). Soil moisture was measured at each site with two sets of time-domain reflectometry (TDR) probes installed at depths of 0.2, 0.4, 0.6, 0.8, 1.0, 1.5, 2.0, 2.5 and 3.0 m (Fig.…”

Section: Methods Of Investigationmentioning

confidence: 96%

Effects of surface run-off on the transport of agricultural chemicals to ground water in a sandplain setting

Delin

Landon

2002

Science of The Total Environment

View full text Add to dashboard Cite

“…Note in this context that the relevant rates of liquid-vapor isotopic exchange may depend upon, for example, properties of the geologic material (Hsieh et al, 1998b;Wassenaar et al, 2008), physicochemical states (Ingraham and Criss, 1998), and saturation controlled liquid surface area to volume ratio (Ingraham and Criss, 1993;Costanza-Robinson and Brusseau, 2002), with implications for the actual resolvability of dynamic liquid pore water signatures. In addition and similar to previous sampling approaches (e.g., Landon et al, 1999;FigueroaJohnson et al, 2007;Wassenaar et al, 2008), the process information may be blurred by unconsidered alteration of liquid soil water isotopic composition itself (e.g., due to interactions with inorganic or organic soil constituents) or unclear contribution of water stored in different compartments of the pore space (e.g., Brooks et al, 2010).…”

Section: Assumptions and Potential Limitationsmentioning

confidence: 72%

“…Conventionally, measurement of water stable isotopic composition was relatively labor-, time-, and cost-intensive and constrained to laboratory-bound analysis of previously collected and processed discrete samples based on gas source isotope ratio mass spectrometry (IRMS) (Horita and Kendall, 2004). Pore water samples were most commonly obtained through destructive collection of geologic material and subsequent extraction using various methods (e.g., Buttle and Sami, 1990;Ingraham and Shadel, 1992;Walker et al, 1994;West et al, 2006) or, less frequently, using suction or gravity lysimeters (e.g., Stewart and McDonnell, 1991;Wels et al, 1991;Landon et al, 1999;Figueroa-Johnson et al, 2007). Each method is, however, associated with considerable uncertainty and unclear implications for the representativeness of obtained pore water isotopic signatures.…”

Section: T H M Volkmann and M Weiler: Pore Water Stable Isotopes mentioning

confidence: 99%

Continual in situ monitoring of pore water stable isotopes in the subsurface

Volkmann

Weiler

2014

Hydrol. Earth Syst. Sci.

113

129

View full text Add to dashboard Cite

Abstract. Stable isotope signatures provide an integral fingerprint of origin, flow paths, transport processes, and residence times of water in the environment. However, the full potential of stable isotopes to quantitatively characterize subsurface water dynamics is yet unfolded due to the difficulty in obtaining extensive, detailed, and repeated measurements of pore water in the unsaturated and saturated zone. This paper presents a functional and cost-efficient system for nondestructive continual in situ monitoring of pore water stable isotope signatures with high resolution. Automatic controllable valve arrays are used to continuously extract diluted water vapor in soil air via a branching network of small microporous probes into a commercial laser-based isotope analyzer. Normalized liquid-phase isotope signatures are then obtained based on a specific on-site calibration approach along with basic corrections for instrument bias and temperature dependent isotopic fractionation. The system was applied to sample depth profiles on three experimental plots with varied vegetation cover in southwest Germany. Two methods (i.e., based on advective versus diffusive vapor extraction) and two modes of sampling (i.e., using multiple permanently installed probes versus a single repeatedly inserted probe) were tested and compared. The results show that the isotope distribution along natural profiles could be resolved with sufficiently high accuracy and precision at sampling intervals of less than four minutes. The presented in situ approaches may thereby be used interchangeably with each other and with concurrent laboratory-based direct equilibration measurements of destructively collected samples. It is thus found that the introduced sampling techniques provide powerful tools towards a detailed quantitative understanding of dynamic and heterogeneous shallow subsurface and vadose zone processes.

show abstract

Comparison of the stable-isotopic composition of soil water collected from suction lysimeters, wick samplers, and cores in a sandy unsaturated zone

Cited by 98 publications

References 27 publications

Desiccation-crack-induced salinization in deep clay sediment

Desiccation-crack-induced salinization in deep clay sediment

Effects of surface run-off on the transport of agricultural chemicals to ground water in a sandplain setting

Continual in situ monitoring of pore water stable isotopes in the subsurface

Contact Info

Product

Resources

About