Assessment of Artificial Groundwater Recharge in Some Wadies in

Assessment of Artificial Groundwater Recharge in Some Wadies in

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 8th Gulf Water Conference
Manama – Bahrain
3 – 6 March 2008
Location map of the United Arab Emirates
53o
54o
Iraq
56o
Ras Al Khaimah
N
Iran
Kuwait
55o
Diba
Qatar
Saudi
Arabia
UAE
Dubai
25o
Arabian Gulf
Kalba
Arabian
Sea
AFRICA
Abu Dhabi
Al Ain
24o
OMAN
UNITED ARAB
EMIRATES
23o
ARABIA
Al Matri A. S. 2008
50 km
Gulf of Oman
52o
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 .
Al Matri A. S. 2008
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.
Al Matri A. S. 2008
The Main Geomorphic Features in the UAE
53o
54o
55o
56o
Ras Al Khaimah
N
25o
Mountains
Gravel Plains
Linear Dunes, Star Dunes and Playa Deposits
Ancient and Recent Dunes
Coastal Sabkhas
Arabian Gulf
Diba
Dubai
Kalba
Abu Dhabi
Al Ain
24o
OMAN
UNITED ARAB
EMIRATES
23o
ARABIA
Al Matri A. S. 2008
50 km
Gulf of Oman
52o
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 Semail 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.
Al Matri A. S. 2008
Geologic Map of the United Arab Emirates
53o
QUATERNARY
Eolian Sand
Surfacial Gravels
Gypsum Deposits
Sabkha Deposits
TERTIARY
54o
Marl and Limestone
N
Arabian Gulf
Limestone, Marl and Sandstone
Semail Ophiolite
Hawasina Complex
Musndam Limestone
JURRASSIC
Hith Anhydrite and arab Formatin
TRIASSIC
56o
Ras Al Khaimah
Diba
25o
CRETACEOUS
55o
Gulf of Oman
52o
Dubai
Kalba
Abu Dhabi
Triassic and Permian Rocks
Al Ain
24o
OMAN
UNITED ARAB
EMIRATES
23o
ARABIA
Al Matri A. S. 2008
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 .
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.
Al Matri A. S. 2008
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.
Al Matri A. S. 2008
Major Drainage Basins
56o
55o
N
26o
Main Geologic Structures
26o
Shaam
1
2
Arabian
Gulf
Arabian
Gulf
OMAN
18
4
Dubai
19
5
7
9
o
16
Fujairah
Kalba
13
14
25o
24 Khor Fakkan
27
17
10
UNITED
25
ARAB
EMIRATES
22
15
8
UNITED
ARAB
EMIRATES
Fujairah
Kalba
23
24o
OMAN
OMAN
Fold
Fault
Thrust Fault
Fracture
12
Al Matri A. S. 2008
Gulf
of
Oman
Dubai
Diba
Water
Divide
Ras Al Khaimah
Ajman
Sharjah
Umm Al Quwain
Sharjah
OMAN
Umm Al Quwain
3
6
Shaam
Diba
Gulf
of
Oman
Ras Al Khaimah
Ajman
56o
N
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
Sewage Recycled Water
Al Matri A. S. 2008
: Total capacity 1370
: Total capacity 309
MCM / y
MCM / y
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.
Al Matri A. S. 2008
The Main Aquifers in the United Arab Emirates
N
25o
53o
54o
Northern limestone aquifer
Ophiolite aquifer
Eastern gravel aquifer
Western gravel aquifer
Sand dune aquifer
Coastal sabkhas
55o
56o
Ras Al Khaimah
Diba
Dubai
Kalba
Arabian Gulf
Abu Dhabi
Al Ain
24o
OMAN
UNITED ARAB
EMIRATES
23o
ARABIA
Al Matri A. S. 2008
50 km
Gulf of Oman
52o
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.
Al Matri A. S. 2008
Sabkha
Deposits
Al Matri A. S. 2008
Western Desert
Area
Al Jaww
Plain
Northern Oman
Mountains
Khatt and Siji
Springs
Arabian
Gulf
Jabal Hafit
W
Regional groundwater flow system
Intermediate groundwater flow system
Local groundwater flow system
Bu Sakhnah Spring
Groundwater Flow Systems in
UAE
E
Gulf of
Oman
Sea Level
Wurrayah Dam
Al Matri A. S. 2008
Dam Location
Wadi Wurrayah – Fuj.
Completion Date
December 1997
Dam Purpose
Groundwater Recharge
and Flood Protection
Reservoir Capacity
5.2 million cubic meters
Dam Type
Earth – Rock Fill
Dam Height
33 meter
Dam Length
150 meter
Benefited Area
Khor fakkan , Bedyah
Al Matri A. S. 2008
Water storage in Wur Dam during the period
2001 - 2006
Storage ( MCM )
3.50
3.00
2.50
2.00
1.50
1.00
0.50
0.00
Year
2001
Al Matri A. S. 2008
2002
2003
2004
2005
2006
Mean annual variation in groundwater level
for some observation wells in Wurrayah
Water level from msl ( meter )
180
160
Wur - 1
140
Wur - 3
120
Wur - 4
100
Wur - 5
80
60
40
20
0
Year 2001
Al Matri a. S. 2008
2002
2003
2004
2005
2006
Ground water level variation during rain season ( 2007 )
for some observation wells in Wurrayah
Water level from msl (meter )
180
160
140
Wur - 1
120
Wur - 3
100
Wur - 4
80
Wur - 5
60
40
20
0
Month
AUG
Al Matri A. S. 2008
SEPT
OCT
NOV
DEC
Schoeller – Berkaloff Diagram (Wur Basin)
140
Mean Wur 3
Mean Wur 5
Mean Wur 6
Mean Wur Dam
120
Content (mg/l)
100
80
60
40
Al Matri A. S. 2008
SO4
Cl
Ca
Mg
K
Na
0
HCO3+CO3
20
Variation of 3H content in the Dam water and
observation wells in Wurryah Basin
Tritium content (TU)
3
2,5
2
1,5
1
0,5
WUR3
WUR5
WUR6
Dam
0
2003.03.23
2003.03.16
2003.02.16
2003.02.05
Al Matri A. S. 2008
2003.01.28
2003.01.22
2003.01.15
2003.01.04
2002.12.28
2002.12.22
2002.12.18
2002.12.14
2002.12.09
2002.12.01
Date of sampling
Tawyeen Dam
Al Matri A. S. 2008
Schoeller-Berkaloff Diagram (Tw Basin )
600
Mean TW
Mean TW
Mean TW
Mean TW
Mean TW
Mean TW
Content (mg/l)
500
400
2
6
8
9
10
Dam
300
200
100
Al Matri A. S. 2008
HCO3+CO3
SO4
Cl
Ca
Mg
K
Na
0
Characteristic stable isotope concentrations of some
major aquifer in the Gulf region and Middle East
Deuterium (o/oo SMOW)
20
Sea
water
10
Quaternary
Aquifer UAE
Wadi Al Bih
Aquifer UAE
0
Yarmok Basin
Middle Aquifer
Jordan
Jabal Hafit
aquifer UAE
-10
-20
Liwa
Aquifer
UAE
Yarmok Basin
Basalt Aquifer
Syria
Shallow
Aquifer
Qatar
Dammam
Aquifer Kuwait
-30
Neogene
Saudi Arabia
-40
Umm er Raduma
Saudi Arabia
-50
-7
-6
-5
Al Matri A.S. 2008
-4
-3
-2
-1
0
Oxygen-18 (o/oo SMOW)
1
2
3
Tritium content (TU)
Variation of 3H content in the Dam water and
observation wells in Tawyeen basin
8
7
6
5
4
3
2
1
0
TW2
TW6
TW8
Dam
TW9
TW10
2002.11.04
2003.07.28
Al Matri A. S. 2008
2002.11.04
2003.10.14
2002.12.06
2002.12.06
2002.11.20
2002.07.11
2002.11.20
Date of sampling
18O
/ 2H Diagram of Wurrayah , Tawyeen
Dams and Observation Wells
Wur wells
60
Suposed position
of the EMWL
confirmed by the non
evaporated rain water
TW wells
Wur dam
TW dam
40
North UAE MWL
GMAL
OMWL
EMWL
20
Rain Avarage in UAE
Evaporation line of the two
dams water, the Wur wells
water and the evaporated
rain in north UAE
0
Non evaporated rain
waters
Evaporation line of the
TW wells
)
2
H
(‰ vs SMOW
Rain avarage in North UAE
-20
Isotopic composition of the
two dams waters before its
evaporation
Isotopic composition of the rain
water recharching the TW wells
before its evaporation
-40
-60
-10
-8
-6
-4
-2
0
2
 18O (‰ vs SMOW)
Al Matri A. S. 2008
4
6
8
10
Wur. Dam reservoir contribution
estimated by the isotopic balance
Average 18 O
Dam reservoir
contribution ( % )
Wur - 2
- 2.71
43.2
Wur -5
- 2.53
34.1
Wur - 6
- 2.32
22.9
Al Matri A. S. 2008
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 .
Al Matri A. S. 2008
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 .
Al Matri A. S. 2008