The Stable Isotope Characteristics of Precipitation in the Middle East Highlighting the Link between the Köppen Climate Classifications and the δ18O and δ2H Values of Precipitation

The Middle East is faced with a water shortage crisis due to its semiarid and arid climate. In this paper, precipitation as an important part of the water cycle was evaluated in 43 stations across the Middle East using the stable isotope technique to study the parameters which influence the stable isotope content of precipitation. First, the stepwise regression model was applied to determine the main geographical and climatological factors affecting the stable isotopes in precipitation. Secondly, the stepwise model was also used to simulate the stable isotope values in precipitation. Furthermore, due to the notable climatic variations across the Middle East, the precipitation sampling stations were classified into six groups based on the Köppen climate zones. Significant variations in the stable isotope values of precipitation were observed in the stations of each climate zone. Finally, the Middle East meteoric water line was developed for the dry and wet periods based on the average stable isotopes in the studied stations. The developed lines showed a lower slope compared to the GMWL due to the higher air temperature and relative humidity in the Middle East compared to the average global conditions. To conclude, the stable isotope contents in precipitation showed significant temporal and spatial variations due to the notable climatic variations across the Middle East.

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Isotope Evidence of Rainfall and Groundwater for Tracing Recharge Areas in Kaeng Khoi District, Saraburi Province, Thailand

Applied Environmental Research ◽

10.35762/aer.2016.38.3.5 ◽

2016 ◽

pp. 49-58 ◽

Cited By ~ 1

Author(s):

Wanlapa Wisittammasri ◽

Srilert Chotpantarat

Keyword(s):

Stable Isotopes ◽

Surface Water ◽

Stable Isotope ◽

Meteoric Water ◽

Water Line ◽

Meteoric Water Line ◽

Isotope Technique ◽

Isotope Evidence ◽

Stable Isotope Technique ◽

Central Thailand

This study was conducted in the districts of Kaeng Khoi and Muang, located in the center of Saraburiprovince, Central Thailand. The purpose was to use a stable isotope technique to iden-tify recharge areas where rainfall infiltrates. Analysis of stable isotopes in groundwater, surface water and rainwater were conducted in September 2014. Isotope compositions of groundwater were found to have δD values that ranged from -37.55‰ to -48.04‰ while δ18O values ranged from -5.30‰ to -7.34‰. The Local Meteoric Water Line (LMWL) in the study area was indis-tinguishablefrom the Bangkok Local Meteoric Water Line (BKK LMWL), and the stable iso-tope values of rainwater in area were more depleted than BKK LMWL. The isotope compo-sitions of surface water revealed that the effect of evaporation could divide the groundwater into two groups, with the first group locally receiving rainfall and the second group interacting directly with surface water. Therefore, care must be taken to prevent groundwater contamination in the latter group due to polluted surface water caused by human activities.

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Dephytinisation of soyabean protein isolate with low native phytic acid content has limited impact on mineral and trace element absorption in healthy infants

British Journal Of Nutrition ◽

10.1079/bjn20031053 ◽

2004 ◽

Vol 91 (2) ◽

pp. 287-293 ◽

Cited By ~ 25

Author(s):

Lena Davidsson ◽

Ekhard E. Ziegler ◽

Peter Kastenmayer ◽

Peter van Dael ◽

Denis Barclay

Keyword(s):

Stable Isotope ◽

Trace Element ◽

Phytic Acid ◽

Protein Isolate ◽

Soya Protein ◽

Faecal Excretion ◽

Phytic Acid Content ◽

Healthy Infants ◽

Isotope Technique ◽

Stable Isotope Technique

Infant formulas based on soyabean protein isolate are often used as an alternative to cows'-based formulas. However, the presence of phytic acid in soya formulas has raised concern about the absorption of trace elements and minerals from these products. The aim of the present study was to evaluate mineral and trace element absorption from regular and dephytinised soya formula in healthy infants. Soyabean protein isolate with a relatively low native content of phytic acid was used for production of a regular soya formula (300 mg phytic acid/kg liquid formula) and an experimental formula was based on dephytinised soya protein isolate (<6 mg phytic acid/kg liquid formula). Using a crossover study design, apparent mineral and trace element absorptions were measured by a stable isotope technique based on 72 h faecal excretion of non-absorbed stable isotopes (Zn, Fe, Cu and Ca) and by the chemical balance technique (Mn, Zn, Cu and Ca) in nine infants (69–191 d old). Fe absorption was also measured by erythrocyte incorporation 14 d after intake. The results from the present study demonstrated that Zn absorption, measured by a stable isotope technique, was significantly greater after dephytinisation (mean value 16·7 v. 22·6 %; P=0·03). No other statistically significant differences between the two formulas were observed. The nutritional benefit of dephytinisation was marginal in the present study. Based on these results, the use of soyabean protein isolate with low native content of phytic acid should be promoted for production of soya formulas and adequate addition of ascorbic acid to enhance Fe absorption should be ensured in the products.

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Conventional and isotopic determinations of shorebird diets at an inland stopover: the importance of invertebrates and Potamogeton pectinatus tubers

Canadian Journal of Zoology ◽

10.1139/z96-117 ◽

1996 ◽

Vol 74 (6) ◽

pp. 1057-1068 ◽

Cited By ~ 44

Author(s):

Stuart A. Alexander ◽

Keith A. Hobson ◽

Cheri L. Gratto-Trevor ◽

Antony W. Diamond

Keyword(s):

Stable Isotope ◽

Potamogeton Pectinatus ◽

Gut Content Analysis ◽

Gut Content ◽

Geographic Ranges ◽

Isotope Technique ◽

Wetland Complex ◽

Limnodromus Scolopaceus ◽

Stable Isotope Technique

We used gut-content and stable-isotope techniques to determine diets of shorebirds staging at a prairie wetland complex. Stable-isotope ratios for carbon (13C/12C) and nitrogen (15N/14N) varied greatly within and among prey types and shorebirds, depending on location within the complex. Both dietary techniques suggested that Long-billed Dowitchers (Limnodromus scolopaceus) and Stilt Sandpipers (Calidris himantopus) ate mostly invertebrates, whereas Hudsonian (Limosa haemastica) and Marbled godwits (Limosa fedoa) ate mainly Potamogeton pectinatus tubers. In comparison, the stable-isotope technique indicated that godwits, especially juvenile Marbled Godwits, ate more invertebrates than is indicated by the gut-content analysis. The discrepancies between methods reflect the potential for bias in the application of these techniques. Researchers using stable isotopes to assess migratory shorebird diets should be aware of possible complications arising from isotopic variability within prey types, even over small geographic ranges. High isotopic variability at inland agro-wetland complexes might preclude reliable isotopic assessment of shorebird diets, especially long term. Rhizivory in godwits may be more common than is generally recognized, especially at inland stopovers during autumn migration in both North America and Eurasia, and should be factored into conservation initiatives for these species.

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Assessment of interconnection between surface water and groundwater in Sawa Lake area, southern Iraq, using stable isotope technique

Arabian Journal of Geosciences ◽

10.1007/s12517-016-2673-6 ◽

2016 ◽

Vol 9 (14) ◽

Cited By ~ 5

Author(s):

K. K. Ali ◽

A. R. Ajeena

Keyword(s):

Surface Water ◽

Stable Isotope ◽

Lake Area ◽

Surface Water And Groundwater ◽

Isotope Technique ◽

Stable Isotope Technique ◽

Southern Iraq

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Every apple has a voice: using stable isotopes to teach about food sourcing and the water cycle

Hydrology and Earth System Sciences ◽

10.5194/hess-21-3799-2017 ◽

2017 ◽

Vol 21 (7) ◽

pp. 3799-3810 ◽

Cited By ~ 4

Author(s):

Erik Oerter ◽

Molly Malone ◽

Annie Putman ◽

Dina Drits-Esser ◽

Louisa Stark ◽

...

Keyword(s):

High School ◽

Stable Isotopes ◽

Stable Isotope ◽

Science Teachers ◽

Water Cycle ◽

Geographic Origin ◽

Agricultural Activity ◽

Isotope Hydrology ◽

Computer Lab ◽

Outreach Activity

Abstract. Agricultural crops such as fruits take up irrigation and meteoric water and incorporate it into their tissue (fruit water) during growth, and the geographic origin of a fruit may be traced by comparing the H and O stable isotope composition (δ2H and δ18O values) of fruit water to the global geospatial distribution of H and O stable isotopes in precipitation. This connection between common fruits and the global water cycle provides an access point to connect with a variety of demographic groups to educate about isotope hydrology and the water cycle. Within the context of a 1-day outreach activity designed for a wide spectrum of participants (high school students, undergraduate students, high school science teachers) we developed introductory lecture materials, in-class participatory demonstrations of fruit water isotopic measurement in real time, and a computer lab exercise to couple actual fruit water isotope data with open-source online geospatial analysis software. We assessed learning outcomes with pre- and post-tests tied to learning objectives, as well as participant feedback surveys. Results indicate that this outreach activity provided effective lessons on the basics of stable isotope hydrology and the water cycle. However, the computer lab exercise needs to be more specifically tailored to the abilities of each participant group. This pilot study provides a foundation for further development of outreach materials that can effectively engage a range of participant groups in learning about the water cycle and the ways in which humans modify the water cycle through agricultural activity.

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