Precipitation origin and evaporation of lakes in semi-arid Patagonia (Argentina) inferred from stable isotopes (δ18O, δ2H)

2007 ◽  
Vol 334 (1-2) ◽  
pp. 53-63 ◽  
Author(s):  
Christoph Mayr ◽  
Andreas Lücke ◽  
Willibald Stichler ◽  
Peter Trimborn ◽  
Bettina Ercolano ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Semi Arid

scholarly journals Tracing sources of stormflow and groundwater recharge in an urban, semi-arid watershed using stable isotopes

2021 ◽  
Vol 34 ◽  
pp. 100806
Author(s):  
Sierra Wallace ◽  
Trent Biggs ◽  
Chun-Ta Lai ◽  
Hilary McMillan
Keyword(s):  
Stable Isotopes ◽  
Groundwater Recharge ◽  
Semi Arid

scholarly journals In-situ unsaturated zone stable water isotope (<sup>2</sup>H and <sup>18</sup>O) measurements in semi-arid environments using tunable off-axis integrated cavity output spectroscopy

2015 ◽  
Vol 12 (6) ◽  
pp. 6115-6149 ◽  
Author(s):  
M. Gaj ◽  
M. Beyer ◽  
P. Koeniger ◽  
H. Wanke ◽  
J. Hamutoko ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Pore Water ◽  
Isotope Analysis ◽  
Vacuum Extraction ◽  
Arid Environments ◽  
Soil Pore Water ◽  
Cavity Output ◽  
Spatio Temporal ◽  
Semi Arid

Abstract. Stable isotopes (deuterium, 2H, and oxygen-18, 18O) of soil pore water were measured directly in the field using tunable off-axis integrated cavity output spectroscopy (OA-ICOS) and commercially available soil gas probes in a semi-arid region of the Cuvelai-Etosha-Basin, Namibia. High spatial and temporal resolution was achieved in the study area with reasonable accuracy and measurements were in agreement with laboratory-based cryogenic vacuum extraction and subsequent cavity ring down laser spectroscopic isotope analysis (CRDS). After drift correction of the isotope data, mean precision for over 140 measurements of two consecutive field campaigns in June and November 2014 were 1.8 and 0.46 ‰ for δ2H and 18O, respectively. Mean Accuracy using quality check standards was 5 and 0.3 ‰ for δ2H and δ18O, respectively. Results support the applicability of an in-situ measurement system for the determination of stable isotopes in soil pore water. Spatio-temporal variability could be deduced with the observed data in an extremely dry evaporation dominated environment which was sporadically affected by intermittent rainfall.

Reliance of creek-side river red gums on creek water

1994 ◽  
Vol 45 (8) ◽  
pp. 1439 ◽  
Author(s):  
PJ Thorburn ◽  
LJ Mensforth ◽  
GR Walker
Keyword(s):  
Stable Isotopes ◽  
Soil Water ◽  
Water Relations ◽  
South Australia ◽  
Eucalyptus Camaldulensis ◽  
Saline Groundwater ◽  
Naturally Occurring ◽  
Creek Water ◽  
Eucalyptus Camaldulensis Dehnh ◽  
Semi Arid

Measurements of naturally occurring stable isotopes of hydrogen (2H) and oxygen (18O) were used to determine the importance of creek waters to river red gums (Eucalyptus camaldulensis Dehnh., Myrtaceae) on the banks of creeks in the semi-arid and saline Chowilla floodplain region of South Australia. The 2H and 18O concentrations of water sampled from trees were significantly different from those of the creek water, indicating that, generally, trees were not obtaining all their water from the creek. This was found even in trees overlying highly saline groundwater. Thus, saline groundwater and/or soil water were important water sources for the trees studied. The results indicated that the water relations of these trees are complex, and the trees may be less affected by changes in creek flow and/or salinity than was previously anticipated.

scholarly journals In situ unsaturated zone water stable isotope (<sup>2</sup>H and <sup>18</sup>O) measurements in semi-arid environments: a soil water balance

2016 ◽  
Vol 20 (2) ◽  
pp. 715-731 ◽  
Author(s):  
Marcel Gaj ◽  
Matthias Beyer ◽  
Paul Koeniger ◽  
Heike Wanke ◽  
Josefina Hamutoko ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Water Balance ◽  
Soil Water ◽  
Root Zone ◽  
Soil Water Balance ◽  
Vacuum Extraction ◽  
Rain Event ◽  
Arid Environments ◽  
Semi Arid

Abstract. Stable isotopes (deuterium, 2H, and oxygen-18, 18O) of soil water were measured in the field using a liquid water isotope analyzer (tunable off-axis integrated cavity output spectroscope, OA-ICOS, LGR) and commercially available soil gas probes (BGL-30, UMS, Munich) in the semi-arid Cuvelai–Etosha Basin (CEB), Namibia. Results support the applicability of an in situ measurement system for the determination of stable isotopes in soil pore water. High spatial and temporal resolution was achieved in the study area with reasonable accuracy and measurements were in agreement with laboratory-based cryogenic vacuum extraction and subsequent cavity ring-down laser spectroscopic isotope analysis (CRDS, L2120-i, Picarro Inc.). After drift and span correction of the in situ isotope data, precision for over 140 measurements taken during two consecutive field campaigns (June and November 2014) was 1.8 and 0.48 ‰ for δ2H and δ18O, respectively. Mean measurement trueness is determined using quality check standards and was 5 and 0.3 ‰ for δ2H and δ18O, respectively. The isotope depth profiles are used quantitatively to calculate a soil water balance. The contribution of transpiration to total evapotranspiration ranged between 72 and 92 %. Shortly after a rain event, the contribution of transpiration was much lower, at 35 to 50 %. Potential limitations of such an in situ system are related to environmental conditions which could be minimized by using a temperature-controlled chamber for the laser spectrometer. Further, the applicability of the system using previously oven-dried soil material might be limited by physicochemical soil properties (i.e., clay minerals). Uncertainty in the in situ system is suggested to be reduced by improving the calibration procedure and further studying fractionation effects influencing the isotope ratios in the soil water, especially at low water contents. Furthermore, the influence of soil-respired CO2 on isotope values within the root zone could not be deduced from the data.

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