Factors controlling stable oxygen, hydrogen and carbon isotope ratios in regional groundwater of the eastern United Arab Emirates (UAE)

Hydrological Processes - Tập 22 Số 12 - Trang 1922-1931 - 2008
Ahmed Murad1, Rajasekar Krishnamurthy2
1Department of Geology, College of Science, UAE University, Al‐Ain, PO Box 17551, United Arab Emirates.
2Department of Geosciences, Western Michigan University, Rood Hall, Kalamazoo, MI 49008, USA

Tóm tắt

Abstract

Increasing groundwater salinity and depletion of the aquifers are major concerns in the UAE. Isotopes of oxygen, hydrogen, and carbon concentrations in groundwater were used to estimate evaporation loss using the isotopes of oxygen and hydrogen, and using a carbon isotope to trace inorganic carbon cycling in two main aquifers in the eastern part of the United Arab Emirates.

The δD‐δ18O of groundwater samples plotted on a line given by: δD = 4 δ18O + 4 ·4 (r2 = 0·4). In comparison, the local meteoric water line (LMWL) has been defined by the line: δD = 8 δ18O + 15. In order to better understand the system investigated, samples were separated into two groups based on the δD‐δ18O relationship. These are (1) samples that plot above the LMWL (δD = 6·1 δ18O + 12·4, r2 = 0·8) and which are located predominantly in the north of the study area, and (2) samples that plot below the LMWL (δD = 5·6 δ18O + 6·2, r2 = 0·8) and which are mostly distributed in the south. Slopes for both the groups are similar and lower than that for LMWL indicating potential evaporation of recharging water. However, the y‐intercept, which differs between the two groups, suggests evaporation of return flow and evapotranspiration in the unsaturated zone to be more significant in the south. This is attributed to intense agricultural activities in the region.

Samples from the eastern Gravel Plain aquifer have δ13C and dissolved inorganic carbon (DIC) values in the range from − 10 to 17‰, and 12–100 mg C/l, respectively, while the range for those from the Ophiolite aquifer is from − 11 to − 16.4‰, and 16–114 mg C/l respectively. This suggests the control of C‐3 and C‐4 plants on DIC formation, an observation supported by the range δ13C of soil organic matter (from − 18·5 to − 22·1‰.) Copyright © 2007 John Wiley & Sons, Ltd.

Từ khóa


Tài liệu tham khảo

Alley RB, 2001, Stable Isotope Geochemistry, 527, 10.1515/9781501508745-012

Alsharhan AS, 2001, Hydrogeology of an Arid Region: The Arabian Gulf and Adjoining Areas, 205

10.1016/S0022-1694(98)00080-8

BakhitDW.1998.Environmental and management problems in the hydrology of the United Arab Emirates. PhD thesis University of South Carolina 9 16 116( in press).

10.1021/ac60068a025

Brunke HP, 1999, A study on salt‐water intrusion in coastal areas of Western Asia: model development and applications, Natuurwetenschappelijk Tijdschrift, 79, 241

10.1111/j.1745-6584.1985.tb01507.x

ClarkIC.1988.Groundwater resources in the Sultanate of Oman: Origins circulation rate recharge processes and paloeoclimatology. Isotopic and Geochemical approaches.Ph.D thesis University de Paris‐Sud France (in press).

Clark ID, 1997, Environmental Isotopes in Hydrogeology, 328

10.1021/ac00243a035

Criss RE, 1999, Principales of Stable Isotope Distribution, 254, 10.1093/oso/9780195117752.001.0001

10.1016/0169-5347(91)90183-X

Electrowatt Engineering Services, 1981, Wadi Ham Dam II and groundwater recharge facilities, Design, 1, 67

Elschami F, 1990, Hydrochemical classification of the groundwater of the Wadi Dibba in the northeastern part of the United Arab Emirates, Journal of the Faculty of Science, 2, 7

10.1016/0016-7037(53)90051-9

Finzi V, 1973, Late Qusubsidence in the musandam expedition, 1971 ‐1972, scientific results: part I, The Geographical Journal, 139, 414

10.1029/WR007i004p00980

10.1029/JC075i015p03039

10.1016/B978-0-444-42225-5.50008-5

Gonfiantini R, 1985, Progress Report for International Atomic Energy

10.1007/978-3-662-03377-7

JICA, 1996, The Master Plan Study on the Groundwater Resources Development for Agriculture in the Vicinity of Al Dhaid in the UAE

Jones GP, 1982, Groundwater resources in the United Arab Emirates, Middle East Water and Science, 6, 41

10.1016/0012-821X(89)90103-9

KulaibAA.1991.Study of the hydrology of the United Arab Emirates by using isotopetechniques ‐internal report Ministry of Electricity and Water: Dubai 16.

10.1111/j.1745-6584.1995.tb00277.x

10.5917/jagh1987.44.3

Ministry of Agriculture and Fisheries, 1986, Drilling of Deep Water Wells at Various Locations in UAE, Groundwater Development in the Eastern Agriculture Region, 107

10.1016/j.jhydrol.2003.09.020

RizkZS El‐EtrHA.1997.Hydrogeology and hydrogeochemistry of some springs in the United Arab Emirates. Symposium on desert studies in the kingdom of Saudi Arabia extant & implementation 27–29Rabi‐II 1415 H 2–4 October 1994 The Arabian Journal for Science and Engineering vol. 22(1C).

RizkZS AlsharhanAS ShindoSS.1997.Evaluation of groundwater resources of United Arab Emirates.Proceedings of the Third Gulf Water Conference vol. 1 Muscat Sultante of Oman 95–122.

Smith BN, 1982, CRC Handbook of Biosolar Resources, 99

StangerG.1986.The hydrogeology of the Oman mountains. British thesis service. PhD thesis The Open University 33 35(in press).

10.1016/S0899-5362(98)00010-4

United Arab Emirates National Atlas, 1993, Remote Sensing Centre, 188

10.1016/B978-0-08-091801-3.50010-6

Wagner W, 1999, Application of environmental isotope methods for groundwater studies in the ESCWA Region, Geolgisc hes Jahrbuch, Reihe C, 37, 129

Yurtsever Y, 1997, Hydrogeochemistry, 3