Liwa Quaternary Sand Aquifer
- 57 Downloads
This chapter investigates the hydrogeology and hydrogeochemistry of the “Liwa Quaternary sand aquifer” in the western UAE. The results of an investigation uncovered the presence of a fresh groundwater lens south of the Bu Hasa Oil Field. A similar aquifer is already known to exist in the area between Madinat Zayed and Liwa Oasis. The aquifers in both areas have similar hydraulic properties, water chemistry and isotopic contents. For this reason, both aquifers are named by the authors the Liwa Quaternary sand aquifer.
The Liwa Quaternary sand aquifer is composed of two fresh/groundwater mounds in Liwa and Bu Hasa and constitutes a relic of an older and larger aquifer system formed during the pluvial periods that affected the northwestern part of Liwa Oasis between 7000 and 5000 years ago. A large mound of an oval shape, 120-km long and 40-km wide, extends between the Liwa Crescent and Madinat Zayed, and another small elliptical mound, with an average diameter of 40 km, occurs between Bu Hasa and Habshan areas. In Liwa, the groundwater depth is <5 to >50 m, and in Bu Hasa the groundwater depth is 24–52 m. The aquifer’s hydraulic parameters are: “hydraulic conductivity (K) is 2.3–8.5 m/d, transmissivity (T) is 200–650 m2/d and specific capacity (SC) is 40–90 m2/d. The aquifer’s saturated thickness varies from <75 m at Shah and Hamim to >175 m between Bu Hasa and Madinat Zayed. The Liwa Quaternary sand aquifer is free (Sy = 0.1–0.3) and heterogeneous (hydraulic gradient = 0.001–0.01)”.
The groundwater in the Liwa Quaternary sand aquifer is: “Fresh where the total dissolved solids (TDS) is ≤1000 mg/L, saline where the TDS is ≥10,000 mg/L, mostly hard (TH > 200 mg/L) and unsuitable for drinking or domestic uses. The concentrations of all cations and anions (except HCO3−) increase from the center of each fresh water mound outwards in all directions”. The average values of sodium adsorption ratios (SARLiwa = 24 and SARBu Hasa = 40) and electrical conductance (ECLiwa = 13,016 μS/cm and ECBu Hasa = 4588 μS/cm) indicates that the groundwater of the Liwa Quaternary sand aquifer can harm conventional crops when used for irrigation. The concentrations minor cations (NO3− and F−) and trace elements (B, Cr and Zn) are higher than the WHO limits for drinking water.
Based on analysis of groundwater chemistry and natural isotopes (2H, 3H, 18O and 14C), the authors identified and characterized regional, intermediate and local groundwater-flow systems in the UAE. The Liwa-Bu Hasa area has a regional groundwater-flow system characterized by an old groundwater of Cl type, low carbon-14 (14C) and tritium (3H) activities. This finding supports the proposed past pluvial periods indicated in previous studies used radiocarbon dating of lacustrine deposits in the Liwa area.
The high level of stable isotopes (2H and 18O) in the Liwa Quaternary sand aquifer indicates high evaporation before recharge. Both isotopes are identical in the aquifer at Bu Hasa Oil field and Liwa Oasis, reflecting the similarity of groundwater characteristics in both areas. The absence of 3H and low level of 14C in groundwater samples collected from of the aquifer suggest old-age groundwater and lack of recharge in the present time.
- Alsharhan AS, Rizk ZS, Nairn AEM, Bakhi DW, Alhajari SA (2001) Hydrogeology of an arid region. The Arabian gulf and adjoining areas. Elsevier Publishing Company, Amsterdam, p 331Google Scholar
- Al Amari KA (1997) Assessment of environmental impact of re-injecting oil-field water in the Miocene clastic sediments on the shallow aquifer at Bu Hasa oil field, United Arab Emirates: Unpublished M. Sc. Thesis, UAE University, Al Ain, United Arab EmiratesGoogle Scholar
- Clark ID (1984) Groundwater resources in the Sultanate of Oman – origin, circulation times, recharge processes and paleoclimatology. Isotopic and geochemical approaches: Ph. D. Thesis, Universite de Paris-Sud, p 264Google Scholar
- Clark ID, Fritz P (1997) Environmental isotopes in hydrogeology. CRC, Florida, p 328Google Scholar
- Driscoll FG (1986) Groundwater and wells. Johnson Filtration Systems, Inc., St. Paul, p 1089Google Scholar
- Embabi NS (1991) Dune types and patterns in United Arab Emirates using Landsat TM data. In: The 24th international symposium on remote sensing of environment, Rio de Janeiro, Barazil, p 13Google Scholar
- Freeze RA, Cherry JA (1979) Groundwater. Prentice-Hall, Englewood Cliffs, p 604Google Scholar
- Garg SP (1978) Groundwater and tube wells. Oxford/IBH Publishing Co., New Delhi, p 333Google Scholar
- GeoConsult (1985) Projects 21/81, drilling of deep water wells at various locations in the UAE, v. III, 1. Masfut, 2. Al Ain, 3. Al Wagan, 4. Medeisis, 5. Liwa. United Arab Emirates, Ministry of Agriculture and Fisheries, Water and Soil Department, Unpublished Report on file at Ministry of Agriculture and Fisheries, DubaiGoogle Scholar
- Hadley DG, Brouwers EM, Bown TM (1998) Quaternary paleodunes, Arabian Gulf coast, Abu Dhabi Emirate – age and paleoenvironmental evolution. In: Alsharhan AS, Glennie KW, Whittle GL, St CG, Kendall C (eds) Proceedings of the international conference on quaternary deserts and climate change. Balkema, Rotterdam, pp 123–139Google Scholar
- Hassan AA, Al Aidarous A (1985) Regional aquifer geology—onshore Abu Dhabi: Abu Dhabi Company for onshore operations report no. 210572/573, p 9Google Scholar
- Hem JD (1985) Study and interpretation of chemical characteristics of natural water, U. S. Geological survey water supply paper no. 1473Google Scholar
- Imes JL, Hutchinson CB, Signor DC, Tamayo JM, Mohamed FA, Hadley DG (1994) Ground-water resources of the Liwa Crescent area, Abu Dhabi Emirate: U.S. Geological Survey Administrative Report 94–001. U. S. Geological Survey-Abu Dhabi National Drilling Company, p 138Google Scholar
- McCutcheon SC, Martin JL, Barnwell TO (1993) In: Maidment DR (ed) Handbook of hydrology. Chapter II, waterGoogle Scholar
- Rizk ZS (2014) Determining the sources of nitrate pollution of the Liwa Quaternary aquifer in the United Arab Emirates. In: WSTA 11th Gulf water conference, water in GCC. Towards efficient management, 20–22 October 2014, Muscat, Sultanate of Oman, pp 120–136Google Scholar
- Rizk ZS, Alsharhan AS (2003) Water resources in the United Arab Emirates. In: Alsharhan AS, Wood WW (eds) Water management perspectives. Evaluation, management and policy. Elsevier Science, Amsterdam, pp 245–264Google Scholar
- Rizk ZS, Alsharhan AS, Shindo SS (1997) Evaluation of groundwater resources of United Arab Emirates. Proceedings of the Third Gulf Water Conference, Muscat, Sultanate of Oman, pp 95–122Google Scholar
- WHO (World Health Organization) (1984) WHO guidelines for drinking water quality. Volume 1, recommendations. WHO, Geneva, p 130Google Scholar
- Wood WW, Imes J (2003) Dating of Holocene groundwater recharge in western part of Abu Dhabi UAE: constrains on global climate-change models. In: Alsharhan AS, Wood WW (eds) Water resources perspective: evaluation, management and policy. Development in water science 50, Elsevier, Amsterdem, p 379–385Google Scholar
- Wood WW, Rizk ZS, Alsharhan AS (2003) Timing of recharge, and the origin, evolution and distribution of solutes in a hyperarid aquifer system, developments in water science (50). In: Alsharhan AS, Wood WW (eds) Water resources perspectives. Evaluation, management and policy. Elsevier, Amsterdam, pp 245–264Google Scholar