youssef Shawky SHERIEF "Flash flood mitigation and water harvesting in wadi al khoud, sultanate of oman" Flash flood mitigation and water harvesting in Wadi Al-Khoud, Sultanate of Oman"

Sultan Qaboos University
College of Arts & Social Sciences
Geography Department

Flash flood mitigation and water harvesting in
Wadi Al-Khoud, Sultanate of Oman
UNCCD 2nd Scientific Conference
9-12 April 2013 - Bonn, Germany

Dr. Youssef Shawky Youssef Sherief
Physical Geography & Remote Sensing
sherief@squ.edu.om


Water harvesting…..why?

For supplying more water in arid and semi arid areas

For increasing the groundwater level

An active method to improve the quality of groundwater

An active method to mitigate the aridity

To mitigate flash flood hazards

to decrease of Soil degradation

One of few methods characterized by low-cost and realizable.

An economic way to reduce value of water bills


 Arid and semiarid regions are increasingly suffering from
water resource shortage as a result of population
 Sultanate of Oman is located in an arid zone that is subjected
to flash flooding Records show that major flash floods
occurred in Oman in 2003, 2005, 2007, 2010, and 2013. Wadi
Oday, Wadi Al-Kabir, and Wadi Al-Khoud.
 Nevertheless Oman's water resources are under increasing
pressure. This could soon lead to a several problems for the
development.
 So, water harvesting could be one of the best methods in
solving decreasing water in the area.


- Wadi Al-Khoud Dam 2011


- More water from flash flood in Wadi Al-Khoud Basin, 2012

Geography Department The study area
57°50'0"E 58°0'0"E 58°10'0"E 58°20'0"E

Wadi network of Wadi Al-Khoud from DEM

Stream orders
52°0'0"E 54°0'0"E 56°0'0"E 58°0'0"E
± 60°0'0"E
 Wadi Al-Khoud is one of the
1 ±

26°0'0"N
2
Oman sea important drainage basins

24°0'0"N
El-

3 Ba Sohar

W
tin

.H
ah

ag
pla

ar
in Muscat

E.
M

H
ou

ag
n ta

ar
Ebri

in

M
s

ou
4

nt
Nizwa Sur

occupying the eastern side of

ain
s
22°0'0"N
Sh
Rabaa Khaly arq

5
iah
sand san
d

s
p lain
el
av
20°0'0"N

Gr
6

nd
sa
ie
Al Hager Mountain in Oman

ad
W
Main channel Arab sea

7
18°0'0"N

Difar Mountains

Salalah

with a total surface area of
0 50 100 200
16°0'0"N

Km

Wadi Mansah

Wadi Fanga about 1740 km2
Wadi Al Rak
Wadi Samael

Wadi El Aaq

Wadi bany Rawaha

0 5 10 20
Km

Data and Methods
 Outcrop lithology and structure
 Climate conditions (temperature, evaporation, and rainfall)
 Hydrological settings
 Spatial analysis using GIS and remote sensing to extract contour lines with
interval 50m.
 extract the catchment area, and wadi networks.
 Determination the suitable places to construct some Dams
57°50'0"E 58°0'0"E 58°10'0"E 58°20'0"E 57°50'0"E 58°0'0"E 58°10'0"E 58°20'0"E 57°50'0"E 58°0'0"E 58°10'0"E 58°20'0"E

57°50'0"E 58°0'0"E 58°10'0"E 58°20'0"E

Geology of Wadi Al-Khoud
Outcrop lithology

23°40'0"N
Alluvial deposits
23°40'0"N

23°40'0"N
23°40'0"N

Aeolian deposits
Khabra deposits
Piedmont facies
Shelf facies
Shelf, slope and basin facies
Basin facies
Shelf facies
Basin, slope and shelf facies
Shelf facies

23°30'0"N
23°30'0"N

23°30'0"N
23°30'0"N

Alluvial and shelf facies
Upper extrusives
Intrusives - Peridotite, gabbro
Sheeted dyke complex
Cumulate and High level gabbro
Dunite
Tectonized harzburgite
metasedimentary rocks
Volcanic rocks
23°20'0"N

23°20'0"N
23°20'0"N
23°20'0"N

Main Faults
23°10'0"N

23°10'0"N

23°10'0"N
23°10'0"N

Km
0 5 10 20


57°50'0"E 58°0'0"E 58°10'0"E 58°20'0"E

Outcrop lithology
Geology of Wadi Al-Khoud  Outcrop lithology has been
Alluvial deposits
Aeolian deposits
played an important role to
Khabra deposits
Piedmont facies harvest rainfall through kind of
Shelf facies
Shelf, slope and basin facies
Basin facies
rocks.
Shelf facies
Basin, slope and shelf facies
Shelf facies
Alluvial and shelf facies  The igneous and volcanic rocks
Upper extrusives
Intrusives - Peridotite, gabbro
Sheeted dyke complex
cover 55%, whereas,
Cumulate and High level gabbro
Dunite
Tectonized harzburgite
metamorphic rocks cover 3%,
metasedimentary rocks
Volcanic rocks
sedimentary rocks 16%, and
Main Faults
recent deposits cover 26%

 Structure geology is very
important, whereas it helps to
increase the ground water
storage during rainfall and runoff
0 5 10
Km
20 specially in the main streams of
wadis


Climate and hydrological setting
 The climate of Oman is extremely hot and dry most of year.

 The mean summer temperature of the study area is 33 C. So, the
evaporation and evapotranspiration are mostly more than rainfall
which reaches of 197mm/y.

 Generally, Flash floods within the hot desert are characterized by
high velocity and low duration with sharp peak discharges.

 the catastrophic of desert floods is the time of peak discharge which
usually is less than one hour, and often the flood comes as a wall of
water.

 The recent dam is not sufficient to protect the building area and the
governorate aims to build another dam to keep the flooding water
and protect the infrastructure.


 There are 22 precipitation stations distributed over Muscat
governorate.
 The average annual rainfall in Muscat is around 63mm (Al Khoud
station) to 210mm (Jabal Bani Jabir).
 In Samail watershed, there are 8 stations for rainfall records.

Ghazi Ali Al-Rawas, 2006


Flood Protection Dams
Project will consist of a
series of flood retention
dams to be built in the
upper catchment of Wadi
Samael
In the first phase of its
implementation, a huge
flood protection dam is
proposed to be built about
7 km upstream of the
existing Al Khoud
recharge dam, not far from
the Al Khoud Village.

Monday, February 14, 2011/Rabee al Awal 10, 1432 AH


Water harvesting using Al Aflag in Wadi Al Khoud

Al Aflag in Wadi Al Khoud


 There are strong
relationship
between Wadi
network density and
slopes in Wadi
Alkoud.

 So, the situation of
dams depend
mostly on the
surface and slopes

57°50'0"E 58°0'0"E 58°10'0"E 58°20'0"E

Wadi network of Wadi Al-Khoud from DEM
 It could be constructing
Stream orders
±
1
some charging dams
2
3 across the main streams
4
5 which had more Faults to
6
Main channel
7
increase and improve

Wadi Mansah
groundwater like: Wadi
Wadi Fanga Al Rak and Wadi Samael
Wadi Al Rak
Wadi Samael

Wadi El Aaq

Wadi bany Rawaha

0 5 10 20
Km

Geography Department Results

Suggestion sites of dams
wadi Latitude longitude
Al-Khoud 23°29′4″ 58°6′13″
Fanga 23°23′52″ 58°6′44″
Al Aaq 23°21′32″ 58°6′10″
! Al-Khoud
( Samael 23°18′34″ 57°56′53″
Al Rak 23°19′14″ 58°12′49″

Fanga !
( Manah1 23°23′24″ 58°8′27″
! Manah 1
(
Al Aaq !
( Manah2 23°18′47″ 58°9′55″
Al Rak
Manah 2 !
(
! Samael
( !
(


Some places are suitable to build storage and charging dams in Wadi Al Rak


Wadi Al Aaq


Wadi Fanga
Wadi Samael


Main stream of Wadi Al Khoud


Conclusions
 Hydrological and climatic settings of Wadi Al-Khoud
confirmed that the recent dam is not sufficient to protect the
building area behind it and must be constructing series of
dams on the main streams of the Wadi Al Khoud.
 The advanced GIS and RS techniques, field work, hydrology,
geologic and structure settings of study area had cleared the
vision to select the best 7 places for construction storage,
charging, and protected dams.
• Finally, the suggestion site of dams could be helping to
mitigate flood hazard and water harvesting which can be used
in sustainable development in the region


Thanks

Dr. Youssef Sherief
sherief@squ.edu.om

youssef Shawky SHERIEF "Flash flood mitigation and water harvesting in wadi al khoud, sultanate of oman" Flash flood mitigation and water harvesting in Wadi Al-Khoud, Sultanate of Oman"

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youssef Shawky SHERIEF "Flash flood mitigation and water harvesting in wadi al khoud, sultanate of oman" Flash flood mitigation and water harvesting in Wadi Al-Khoud, Sultanate of Oman"