Assessment of Artificial Groundwater Recharge in Some Wadies in UAE by using Isotope Hydrology Techniques

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1 Assessment of Artificial Groundwater Recharge in Some Wadies in UAE by using Isotope Hydrology Techniques Presented by : Ahmed Saif Al Matri Head, Water Resources Section Ministry of Environment & Water U.A.E Prepared for : The 8 th Gulf Water Conference Manama Bahrain 3 6 March 2008

Qatar UAE Dubai Diba 25 o Arabian Gulf Kalba AFRICA Arabian Sea

2 Gulf of Oman Location map of the United Arab Emirates 52 o 53 o 54 o 55 o 56 o Iraq Kuwait Iran N Ras Al Khaimah Saudi Arabia Qatar UAE Dubai Diba 25 o Arabian Gulf Kalba AFRICA Arabian Sea Abu Dhabi 24 o Al Ain UNITED ARAB EMIRATES OMAN 23 o ARABIA 50 km

3 Climate The UAE has an arid to semi-arid climate with high temperature and infrequent irregular low rainfall. Mean max. temperature reach > 40 o C in summer. High relative humidity ( reaches > 97 % ). Average daily evaporation 8.2 mm. Average annual mean rainfall is around 115 mm.

GEOMORPHOLOGY AND GEOLOGY The geomorphic features have a major role in

Geology, on the other hand, encompasses the distribution of outcrops,

These greatly influence runoff volumes, infiltration rates and surface and

4 GEOMORPHOLOGY AND GEOLOGY The geomorphic features have a major role in controlling the movement of both surface and groundwater. Geology, on the other hand, encompasses the distribution of outcrops, stratigraphic sequences, and structural zones. These greatly influence runoff volumes, infiltration rates and surface and groundwater quality. The following discussion outlines the main geomorphic features in UAE, geologic setting, and structural elements.

5 Gulf of Oman The Main Geomorphic Features in the UAE 52 o 53 o 54 o 55 o 56 o Ras Al Khaimah N 25 o Mountains Gravel Plains Linear Dunes, Star Dunes and Playa Deposits Ancient and Recent Dunes Coastal Sabkhas Arabian Gulf Dubai Diba Kalba Abu Dhabi 24 o Al Ain UNITED ARAB EMIRATES OMAN 23 o ARABIA 50 km

late Cretaceous, and two allochthonous sequences. The lower sequence is composed of sedimentary rocks and is known as the Hawaina Group.

6 Geologic Setting The northern Oman Mountains in UAE are composed of two major classes of rocks. The first is an authothonous sequence including Proterzoic basement rocks and some early Paleozoic sediments covered transgessively by carbonate platform deposits ranging in age from late Permian to late Cretaceous, and two allochthonous sequences. The lower sequence is composed of sedimentary rocks and is known as the Hawaina Group. This sequence is overlain by the S Suite, which consists of a slab of former oceanic crust. The Maastrichtian to Neogene sediments was laid down after the main episode of nappe emplacement. The actual relief of the Oman Mountains is due to tectonic movements that occurred during post-nappes times, i.e. during the Cenozoic. These movements resulted in the uplifting of the mountains.

Gulf of Oman Geologic Map of the United Arab Emirates 52 o 53 o 54 o 55 o 56 o QUATERNARY Eolian Sand Surfacial Gravels Gypsum Deposits Sabkha Deposits N Ras Al Khaimah Diba TERTIARY CRETACEOUS 25 o

7 Gulf of Oman Geologic Map of the United Arab Emirates 52 o 53 o 54 o 55 o 56 o QUATERNARY Eolian Sand Surfacial Gravels Gypsum Deposits Sabkha Deposits N Ras Al Khaimah Diba TERTIARY CRETACEOUS 25 o JURRASSIC TRIASSIC Marl and Limestone Limestone, Marl and Sandstone S Ophiolite Hawasina Complex Musndam Limestone Hith Anhydrite and arab Formatin Abu Dhabi Triassic and Permian Rocks Arabian Gulf Dubai Kalba Al Ain 24 o OMAN UNITED ARAB EMIRATES 23 o ARABIA 50 km

Geologic Structure The UAE can be differentiated into five structural provinces, from north to south, including: Ru us Al Gibal, Diba zone, ophiolite sequence, wadi Hatta zone, and the western area.

8 Geologic Structure The UAE can be differentiated into five structural provinces, from north to south, including: Ru us Al Gibal, Diba zone, ophiolite sequence, wadi Hatta zone, and the western area. Ru us Al Gibal area is characterized by thrust faults that are inclined in the east and south directions. Sometimes the thrust plain slopes towards east to the zone of overturned and recumbent folds. The Diba zone is a topographically low and extends for 30 km from northeast to southwest, with an average width of 20 km.

9 Geologic Structure The UAE can be differentiated into five structural provinces, from north to south, including: Ru us Al Gibal, Diba zone, ophiolite sequence, wadi Hatta zone, and the western area. Ru us Al Gibal area is characterized by thrust faults that are inclined in the east and south directions. Sometimes the thrust plain slopes towards east to the zone of overturned and recumbent folds. The Diba zone is a topographically low and extends for 30 km from northeast to southwest, with an average width of 20 km.

Major Drainage Basins Main Geologic Structures

Quwain Dubai Arabian Gulf Ajman Ras Al Khaimah

3 Water Divide 9 1 2 18 OMAN OMAN 4 19 13 16

Khor Fakkan Fujairah Kalba 25 o 24 o Arabian

ARAB EMIRATES Ras Al Khaimah OMAN Diba Gulf of

10 Major Drainage Basins Main Geologic Structures N 56 o 55 o 56 o 26 o N Shaam OMAN 26 o Umm Al Quwain Dubai Arabian Gulf Ajman Ras Al Khaimah UNITED ARAB EMIRATES 25 o Sharjah 15 Shaam Water Divide OMAN OMAN Diba Gulf of Oman Khor Fakkan Fujairah Kalba 25 o 24 o Arabian Gulf Umm Al Quwain Ajman Sharjah Dubai UNITED ARAB EMIRATES Ras Al Khaimah OMAN Diba Gulf of Oman Fujairah Kalba Fold Fault Thrust Fault Fracture

Water Resources > Conventional Surface runoff : 25

The groundwater is main resource for agriculture.

). Non-renewable (fossil ) : deep aquifers (

Falajes & Springs : Annual discharge 20 MCM.

11 Water Resources > Conventional Surface runoff : 25 main wadies with average runoff 185 MCM Groundwater : The groundwater is main resource for agriculture. Renewable : shallow alluvial aquifers ( gravel plains ). Non-renewable (fossil ) : deep aquifers ( sedimentary rocks ). Falajes & Springs : Annual discharge 20 MCM. > Non - conventional Desalinated Water : Total capacity 1370 MCM / y Sewage Recycled Water : Total capacity 309 MCM / y

12 The main aquifers in the UAE include : Limestone aquifer in the North and East. Fractured ophiolite group in the East. Gravel aquifers flaking the Eastern Mountain ranges on the East and West. Sand dunes aquifers in the South and West.

13 Gulf of Oman The Main Aquifers in the United Arab Emirates 52 o 53 o 54 o 55 o 56 o 25 o N Northern limestone aquifer Ophiolite aquifer Eastern gravel aquifer Western gravel aquifer Sand dune aquifer Coastal sabkhas Dubai Ras Al Khaimah Diba Kalba Arabian Gulf Abu Dhabi 24 o Al Ain UNITED ARAB EMIRATES OMAN 23 o ARABIA 50 km

The main objective of Dams construction project is to retain surface runoff in the wadies which is going losses to the sea, and achieve : Recharge the g. w. aquifers.

14 The main objective of Dams construction project is to retain surface runoff in the wadies which is going losses to the sea, and achieve : Recharge the g. w. aquifers. Improve water quality and level. Reduce seawater intrusion at the coastal areas. Water harvesting. Flood protection and control. Enhance soil characteristics in the farms by adding silt removed from dams reservoirs.

system Intermediate groundwater flow system Local groundwater flow system

15 Bu Sakhnah Spring Jabal Hafit Khatt and Siji Springs Northern Oman Mountains Groundwater Flow Systems in UAE W Regional groundwater flow system Intermediate groundwater flow system Local groundwater flow system E Arabian Gulf Sabkha Deposits Western Desert Area Al Jaww Plain Gulf of Oman Sea Level

16 Wurrayah Dam

17 Dam Location Wadi Wurrayah Fuj. Completion Date December 1997 Dam Purpose Groundwater Recharge and Flood Protection Reservoir Capacity Dam Type Dam Height Dam Length Benefited Area 5.2 million cubic meters Earth Rock Fill 33 meter 150 meter Khor fakkan, Bedyah

18 Storage ( MCM ) Water storage in Wur Dam during the period Year

19 Water level from msl ( meter ) Mean annual variation in groundwater level for some observation wells in Wurrayah Year Wur - 1 Wur - 3 Wur - 4 Wur Al Matri a. S. 2008

20 Water level from msl (meter ) Ground water level variation during rain season ( 2007 ) for some observation wells in Wurrayah Month Wur - 1 Wur - 3 Wur - 4 Wur - 5 AUG SEPT OCT NOV DEC

21 Na K Mg Ca Cl SO4 HCO3+CO3 Content (mg/l) Schoeller Berkaloff Diagram (Wur Basin) Mean Wur 3 Mean Wur 5 Mean Wur 6 Mean Wur Dam

22 Tritium content (TU) Variation of 3H content in the Dam water and observation wells in Wurryah Basin 3 2,5 2 1,5 1 0,5 0 WUR3 WUR6 WUR5 Dam Date of sampling

23 Tawyeen Dam

24 Na K Mg Ca Cl SO4 HCO3+CO3 Content (mg/l) Schoeller-Berkaloff Diagram (Tw Basin ) Mean TW 2 Mean TW 6 Mean TW 8 Mean TW 9 Mean TW 10 Mean TW Dam

UAE Quaternary Aquifer UAE Shallow Aquifer Qatar Jabal Hafit aquifer UAE Liwa Aquifer UAE -30 Dammam Aquifer Kuwait

25 Deuterium (o/oo SMOW) Characteristic stable isotope concentrations of some major aquifer in the Gulf region and Middle East Sea water Yarmok Basin Middle Aquifer Jordan Yarmok Basin Basalt Aquifer Syria Wadi Al Bih Aquifer UAE Quaternary Aquifer UAE Shallow Aquifer Qatar Jabal Hafit aquifer UAE Liwa Aquifer UAE -30 Dammam Aquifer Kuwait -40 Neogene Saudi Arabia -50 Umm er Raduma Saudi Arabia Al Matri A.S Oxygen-18 (o/oo SMOW)

26 Tritium content (TU) Variation of 3 H content in the Dam water and observation wells in Tawyeen basin TW2 TW6 TW8 Dam TW9 TW10 Date of sampling

27 2 H ( 18 O / 2 H Diagram of Wurrayah, Tawyeen Dams and Observation Wells Wur wells TW wells Wur dam TW dam North UAE MWL GMAL OMWL EMWL Rain Avarage in UAE Rain avarage in North UAE Non evaporated rain waters Suposed position of the EMWL confirmed by the non evaporated rain water Evaporation line of the two dams water, the Wur wells water and the evaporated rain in north UAE Evaporation line of the TW wells Isotopic composition of the two dams waters before its evaporation Isotopic composition of the rain water recharching the TW wells before its evaporation O ( vs SMOW)

28 Wur. Dam reservoir contribution estimated by the isotopic balance Wur - 2 Average 18 O Dam reservoir contribution ( % ) 43.2 Wur Wur

29 Discussion : Drawdown range between 4 10 m due to extensive use. Groundwater level increase due to the storage in the Dam reservoir 2 11 m. Isotope analysis show the a relatively similar variation in the concentration of major elements in both Dam and Observation wells. There is meaningful contribution to the recharge through the Wur. Dam in the wadi.

30 Recommendations Considering the significant results obtained from Wurrayah Basin, it is highly recommended : Promote the isotopic methods in water management. Continue investigations for other Basins in the UAE with contribution and support of IAEA. Encourage the use of isotopic tracers for various investigations.

ELECTRICAL RESISTIVITY IMAGING FOR QUATERNARY AQUIFER IN WADI MURAYKHAT AND WADI SA A, AL AIN AREA, UAE.

ELECTRICAL RESISTIVITY IMAGING FOR QUATERNARY AQUIFER IN WADI MURAYKHAT AND WADI SA A, AL AIN AREA, UAE. By: Ahmed. El-Mahmoudi KFU University, Water Studies Centre, KSA Figure (#) Map of Al Jaww Plain