Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-20T07:38:00.206Z Has data issue: false hasContentIssue false
  • English
  • Français

Dynamics of Water Soil Storage in the Unsaturated Zone of a Sand Dune in a Semi-Arid Region Traced by Humidity and Carbon Isotopes: The Case of Ashdod, Israel

Published online by Cambridge University Press:  02 July 2018

Israel Carmi ,
Mariana Stiller  and
Joel Kronfeld
Israel Carmi*
Affiliation:
Tel Aviv University, Tel Aviv, Israel Weizmann Institute of Science, Rehovot, Israel Geological Survey of Israel, Jerusalem, Israel
Mariana Stiller
Affiliation:
Geological Survey of Israel, Jerusalem, Israel
Joel Kronfeld
Affiliation:
Tel Aviv University, Tel Aviv, Israel
*
*Corresponding author. Email: [email protected].
Get access Rights & Permissions [Opens in a new window]

Abstract

A 22 m sediment core was collected from the unsaturated zone (USZ) in the dunes south of Ashdod, Israel, in a low rainfall year, following an even lower-rainfall year. The mineralogy of was quartz with some clay and carbonate. The local climate is semi-arid. The roots of the sparse vegetation can reach ~8 m. The porosity was ~40–55%. The DIC ranged from 2 to 13 mmole C/L. Large variability is noted in the soil moisture, with a maximum at the high clay region at ~8 m. Oxygen isotopes enter the USZ with rain falling on the surface. There is 18O enrichment in the top of the section due to evaporation during the summer. Below this depth δ18O values of ~ –5‰ prevail as in the local aquifer. CO2 and the carbon isotopes enter the USZ laterally by exhalation from roots. The δ13C varies from –5‰ to –23‰, representing stages in carbon isotopic fractionation: CO2gas becomes dissolved CO2aqueous which then forms carbonic acid and HCO3– . The high δ13C, Δ14C, and DIC are found at the 8 m depth. These values along with high humidity are replicated at ~22m depth. They most probably represent recharge water from the previous rainy season at 8 m depth subsequently pushed down 12.8±0.8 m during the last winter.

Keywords

water flowunsaturated zone
Type
Water, Sediment, Karst
Information
Radiocarbon , Volume 60 , Issue 4: 2nd Radiocarbon in the Environment Conference Debrecen, Hungary, July 3–7, 2017 Part 1 of 2 , August 2018 , pp. 1259 - 1267
Copyright
© 2018 by the Arizona Board of Regents on behalf of the University of Arizona 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Carmi, I, Stiller, M, Kronfeld, J, Yechieli, Y, Boaretto, E, Bar-Matthews, M, Ayalon, A. 2006. Radiocarbon loss from DIC in vadose water flow above the Judea Aquifer, Israel. In: Povinec P, Sanchez-Cabeza JA, editors. International Conference on Isotopes and Environmental Studies. Vol. 8. Elsevier. p 297–306.Google Scholar
Carmi, I, Kronfeld, J, Yechieli, Y, Yakir, D, Stiller, M, Boaretto, E. 2007. Quantitative extraction of dissolved inorganic carbon by vacuum distillation for sediments of the unsaturated zone for carbon isotope analysis. Radiocarbon 49(1):83–94.Google Scholar
Carmi, I, Kronfeld, J, Yechieli, Y, Yakir, D, Boaretto, E, Stiller, M. 2009. Carbon isotopes in pore water of the unsaturated zone and their relevance for initial 14C activity in groundwater in the coastal aquifer of Israel. Chemical Geology 268:189–196.Google Scholar
Carmi, I, Yakir, D, Yechieli, Y, Kronfeld, J, Stiller, M. 2013. Variations in soil CO2 concentrations and isotopic values in a semi-arid region due to biotic and abiotic processes in the unsaturated zone. Radiocarbon 55(2–3):933–942.Google Scholar
Clark, ID, Fritz, P. 1997. Environmental isotopes in Hydrogeology. Boca Raton (FL): Lewis Publishers, CRC. p 328.Google Scholar
Dan, J. 1991. The effect of dust deposition on the soils of the Land of Israel. Quaternary International 5:107–113.Google Scholar
Davidson, GR, Hardin, EL, Basset, RL. 1995. Extraction of 14C from pore water in unsaturated rock using vacuum distillation. Radiocarbon 37(3):861–874.Google Scholar
Ganor, E. 1975. Atmospheric dust in Israel-sedimentological and meteorological analysis of dust deposition [PhD thesis]. Jerusalem: The Hebrew University of Jerusalem. (Hebrew with English summary.)Google Scholar
Gat, JR, Dangaard, W. 1972. Stable isotope survey of the fresh water occurrences in Israel and the Northern Jordan Rift Valley. Journal of Hydrology 16(3):177–212.Google Scholar
Klein, T, Hemming, D, Tongbao, L, Grϋnzweig, JM, Maseyk, K, Rotenberg, E, Yakir, D. 2005. Association between tree-ring and needle δ13C and leaf gas exchange in Pinus halpenesis under semi-arid conditions. Oecologia 144:45–54.Google Scholar
Levin, B, Kromer, S, Hammer, C. 2013. Atmospheric Δ14CO2 trend in western European background air from 2000 to 2013. Tellus 65.Google Scholar
Rimon, Y, Dahan, O, Nativ, R, Geyer, S. 2007. Water percolation through the deep vadose zone and groundwater recharge: Preliminary results based on a new vadose zone monitoring system. Water Resources Research 43:WO5402.Google Scholar
Vogel, JC, Fuls, A, Danin, A. 1986. Geographical and environmental distribution of C3 and C4 grasses in the Sinai, Negev and Judean deserts. Oecologia 70:258–265.Google Scholar