Sayı (Number): 1
Global Warming and Trans-Boundary Water
Management in The Tigris-Euphrates-Basin
Küresel Isınma ve Dicle-Fırat Havzası
Sınıraşan Suları Yönetimi
Zekâi ŞEN
Aralık (December) 2016
Istanbul - Turkey
SU KÜLLİYESİ
TURKISH WATER FOUNDATION
WATER FACULTY
SU BÜLTENİ : SAYI 1
Global Warming and Trans-Boundary Water Management
in The Tigris-Euphrates-Basin
Küresel Isınma ve Di̇ cle-Fırat Havzası Sınıraşan Suları Yöneti̇ mi
Zekâi ŞEN
©2016 SU VAKFI
Tüm yayın hakları anlaşmalı olarak Su Vakfı’na aittir.
Kaynak gösterilerek alıntı yapılabilir, izinsiz çoğaltılamaz, basılamaz.
Basıma Hazırlayan :
Muhiddin YENİGÜN
SU VAKFI
SU VAKFI
Libadiye Cad. Doğanay Sokak No:6 Kat:4 Üsküdar İstanbul
Tel: (216) 412 3383 - Faks: (216) 412 3390
[email protected] - www.suvakfi.org.tr
NOTE: This article is a comment and response to the following paper
Swenson, S. C., Wahr, J., and Milly, P. C. D. (2003). Estimated accuracies of regional water storage
variations inferred from the Gravity Recovery and Climate Experiment (GRACE), Water Resources Res., 39(8), 1223, doi:10.1029/2002WR001808.
Global warming and Trans-boundary Water Management in
the Tigris-Euphrates-Basin
Zekâi Şen
Turkish Water Foundation, Libadiye Cad. Doğanay Sok. No:6 Kat 4 Üsküdar İstanbul Turkey
Abstract
Although there is a well balance in the global water resources but the global warming coupled with the climate change and population growth have unprecedented effect on the local
and regional ecosystems, agricultural, economic and social activities. In order to reduce such
undesirable effects on these activities water resources management of available resources
must be achieved in the best possible manner especially trans-boundary regions and global
warming impacts. One of the most disputable regions from the joint water resources management point of view is the Euphrates-Tigris basin, which is shared actively and dominantly
by three countries including Turkey, Syria and Iraq. This paper will present the present and
future status of surface and ground water resources balance in the region through convenient
climate change model results and groundwater balance equations in the region in general and
within Turkey in particular. For this purpose after the explanation of the present situation,
future prediction results from the General Circulation Model (GCM) coupled with Turkish
Water Foundation model, the cumulative monthly precipitation and discharge values are presented in decadal graphs up to 2050. The groundwater resources water balance equations as
available in the literature are refined for better conclusions.
Key words: Euphrates, Tigris, Water, climate change,
1
1. Introduction
middle-stream and up-stream partners of the
same surface water resources, where most
of the time the groundwater resources are
thought a secondary alternative although
they are as significant as the surface runoff
in rivers. Especially, expected global warming and consequent climate change scenarios and their likely effects in the future may
lead to significance of groundwater resources over surface alternatives. Up-stream riparian enjoys the freshness of water resources and their over advantages because of the
mountainous area where the head waters
originate and it can be used as a significant
energy resource, which is renewable and
then the same water can be used in different
activities such as agriculture, groundwater
recharge, industry and domestic usages.
Trans-boundary water resources are
among the most sensitive strategic storages
with concern of each riparian for better allocation in the development of the country.
Scarcity of water resources due to drought
periods on one hand, and long-term global
warming and climate change effects on the
other, increase the value of water in these
watersheds, which are disputable to a certain extent about the water rights among
the riparian sides. Although watersheds
have geographical, meteorological and hydrological unity but their political division
between few countries cause regional water
allocation and management problems that
can be resolved first by their bilateral, and
subsequently, multi-lateral agreements with
conclusive decisions for the benefit of each
riparian. Such an agreement is already in
effect for the release of 500 m3/s from Turkey at the border through Euphrates river to
Syria and then to Iraq. On the other hand,
increase on water supply due to population
growth, global warming and climate change,
technological development and agricultural
activities through irrigation projects for food
security of any country, water resources in a
watershed of trans-boundary nature provide
mutual questions and regional conflicts that
need to be settled in a peaceful manner.
Hydro-politics of the Middle East region
is a focal point not only among the riparian countries, but also scientific and political
interests culminates even from far distant
countries. Water management strategies in
any drainage basin should be thought not
only on equal footings but on the reality of
the meteorology, climatology, topography,
geology, hydrology, hydrochemistry and related aspects collectively, because up-, middle- and down-stream parts in any drainage
basin have specific and local features, which
should be accounted naturally in a harmonious manner. As the authors state Turkish,
Syrian and Iraqi water managers now dictate
the river flows with timed release from the
reservoirs, but it is not mentioned that Turkey releases to downstream countries 500
m3/sec, which is equivalent to 43.2×106 m3/
day or 15.897×109 m3/year. This amount is
about 45% of the whole annual discharge
of Euphrates River. This amount is unconditional, and hence, there is no restriction
whether the year is dry or there is prolonged
drought or the impact of climate change. In
dry and drought years the same amount is
released from the upstream dams. Besides,
Water and its increasing importance due
to many anthropogenic activities (including
global warming and climate change) may
lead to disagreement, and consequent conflicts, especially over trans-boundary water resources in a common watershed with
different riparian. Accordingly different
conflict and even war scenarios over water
rights are brought into daily reports of news
by various researchers (Cooley, 1984; Homer-Dixon, 1991, 1999; Gleditsch, 2003). In
a regional water sharing of a watershed area
among neighbor riparian, they are classified
according to their positions down-stream,
2
in the past in few years (1996-1998) 800
m3/sec of water is released from the reservoirs in Turkey. Such releases are not noted
by international water law (United Nations,
1997). The trans-boundary subsurface and
groundwater flows are not taken into consideration at all. Depletion in groundwater rates
is a fact in many areas as well as in the Middle East region. Furthermore, groundwater
management studies are more complicated
than surface water cases especially in arid
and semi-arid regions (Şen, 1995, 2012).
not only on the up-stream part of a drainage basin but at all parts in an integrated
manner. In drought circumstances, naturally
water management problems become under
the primary focus, and hence, upstream land
parts are frequently at the center of debates.
2. Study area and data
Turkey is the up-stream riparian to Euphrates trans-boundary water resources and
the headwaters of this rives originates from
the mountainous area in the East Central
Anatolian plateau at elevations of more than
2000 m above mean sea level. Over these
mountains precipitation in the forms of
rainfall and especially snow during winter
season provide the main replenishment in
the form of surface and river runoff, which
transgresses Turkish border with Syria and
then between Syria and Iraq. About 100
km, before reaching the Arabian Gulf to
joint with the Tigris River under the name
of the Shattal-Arab as a single watercourse.
Tigris River also originates from Eastern
Anatolian mountainous area also in Turkey.
Euphrates-Tigris river basin is mainly distributed among Turkey, Syria, and Iraq with
increasing debates and scenarios for the last
three decades due to transboundary nature
of surface water resources (Figure 1).
It is the main purpose of this paper to
discuss, develop and propose a model that
results in the precipitation amounts and runoff volumes of the Euphrates-River basin in
Turkey. Additionally, groundwater potential
in the Euphrates-River drainage basin is explained with simple formulations and calculations. These results are the preliminary requirements for the water resources (surface
and groundwater) assessment and the best
possible water balance works in this region.
In general it is observed that although there
is a decreasing tendency in the precipitation
amounts, it is expected to be more severe after 2040.
The Gravity Recovery and Climate Experiment (GRACE) satellite mission data usage
for freshwater storage trend evaluation in
the north-central Middle East and its nearby vicinities brings a supportive dimension
for the assessment of water storage in cases
of missing or unavailable data (Voss et al.,
2013). Such approaches must be encouraged
in the future studies and can be very useful especially for arid and semi-arid regions
of the world. In the Middle East, farmers’
migration to urban centers, destruction of
wet land ecosystems and fallows are not as
a result of water related problems only, but
also due to global warming, climate change,
education, health, economic, political unrest and related reasons. Droughts amplify
the management decisions on a large scale
Figure 1 Study area
Within the same drainage basin, the
groundwater storages between Turkey and
Syria have not been debatable in the negotiations. Prior to three decades Turkey con-
3
centrated on the lower Euphrates project development in the sense that although Turkey
is up-stream riparian in the Euphrates basin
within her national boundaries at that time
close to Syrian boundary the location was
referred to as the Southern Anatolian Project (Güneydoğu Anadolu Project, GAP). It
includes development of a series of engineering water structures for agricultural and
hydropower energy generation in addition
to domestic and industrial water demands.
Present and future global warming and climate change in addition to high population
growth are also significant key factors in
the region for demand on water resources.
None of the factors are crisp but rather fuzzy
(linguistic information) in content, but most
often all the parties talk about the crisp numbers for the settlement of even social, economic and political issues.
Figure 2 The shifts in the climate lines after 1 degree increase in global warmth
4. Surface water potential
Euphrates River and Tigris River basins
are considered frequently as one basin due
to the fact that they merge shortly before
reaching to the Arabian Gulf at Shatt-al-Arab location. They both have their headwaters
in Turkey and they run through Syria and
Iraq. Almost all the waters of the Euphrates
River and a large portion of the Tigris River
waters originate within Turkey.
3. Global climatic change impacts
Land and water ecosystems in addition to
socio-economic systems (agriculture, forestry, and fishery and water resources) are
among the key activities for human development and prosperity. These factors are under
the influence of global warming and climate
change effects, and hence, their optimum
maintenance is responsive to the climatic
change impacts. It has already been noticed
by Şen (2009) that only 1 °C warming in the
global temperature lead to serious climate,
agriculture, water resources pattern changes in different regions of the world. Such
changes may destroy the functions and biological diversity of the forests in moderate
and sub-tropical regions of Euphrates-Tigris
river basin countries. It has been already calculated by Şen (2009) as the simplest model
that 1 °C increase in the global warmth is
expected to cause changes in the present day
climate belt regions of the world about 200
km to 250 km shifts towards polar regions in
this century. The results of this simple model are shown in Figure 2.
The average annual discharge of the Euphrates River is estimated as 32×109 m3 of
which about 90% is generated in Turkey,
and the remaining 10% in Syria. The lower-stream country, Iraq, has virtually no contribution to the discharge of this river.
On the other hand, Tigris River and its tributaries totally provide about 50×109 m3 per
year of this amount 40% comes from Turkey,
whereas Iraq and Iran contribute 51% and
9%, respectively. Syrian has only about 40
km border with the Tigris River, and therefore, virtually does not make any contribution
to this river flow. In general, the total runoff
by Euphrates-River basin is sufficient to cover the needs of the three countries, Turkey,
Syria and Iraq, but each country has different
meteorological, climatological, geological,
and morphological features, and therefore,
different benefit from the water. For instance,
in Turkey the most important benefit is for
4
hydroelectric power, whereas in other countries the weight is towards the agricultural
purposes. This is tantamount to saying that
physical characteristics of these rivers coupled with the major development projects by
EUPHRATES HADCM3A2
8000
3500
monthly
5000
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
4000
runoff (Mm3/sn)
6000
EUPHRATES HADCM3A2
4500
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
7000
4000
Cumulative total
Cumulative total monthly runoff (Mm3/sn)
the riparian put exceeding pressures on the
supply of the river system. Hence, excessive
demand for more water exacerbates tension
in the relations of the riparian with each other (Kibaroglu, 1998).
3000
2000
3000
2500
2000
1500
1000
1000
500
0
J
F
M
A
M
J
Months
J
A
S
O
N
D
0
a
M
A
M
3500
Months
J
A
S
O
N
D
A
S
O
N
D
c
EUPHRATES HADCM3A2
4000
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
3500
3000
runoff (Mm3/sn)
4000
J
b
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
4500
3000
monthly
2500
Cumulative total
2000
1500
1000
500
2500
2000
1500
1000
500
J
F
M
A
M
J
Months
J
A
S
O
N
D
0
c
b
J
F
M
A
M
J
Months
dd
EUPHRATES HADCM3A2
3500
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
3000
Cumulative total monthly runoff (Mm3/sn)
Cumulative total monthly runoff (Mm3/sn)
F
EUPHRATES HADCM3A2
5000
0
J
2500
2000
1500
1000
500
0
J
F
M
A
M
J
Months
J
A
S
O
N
D
e
e
Figure 3. Euphrates drainage basin EH40PYC-A2 scenario CTMF graphs.
5
J
As for the methodology statistical downscaling procedure is employed as developed
specially for the climate change over Turkey
(Şen, 2009: Şen, et al., 2010).
between 2000 and 2050 based on the England-based (Hadley Center) HADCM3-A2
scenario data and modeling based on downscaling procedure in Şen et al. (2010).
Figure 3 depicts the amount of waters
that the Euphrates River will carry to the
borderline on cumulative monthly and annual basis in terms of million cubic meters
Similar graphs are shown in Figure 4 for
Tigris River cumulative monthly and annual
flows between 2000 – 2050 inclusive again
on the basis of A2 scenario.
TIGRIS HADCM3-A2
8000
4000
(Mm3/sn)
5000
4000
3000
2000
3500
3000
2500
2000
1500
1000
1000
0
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
4500
Cumulative monthly total runoff
(Mm3/sn)
6000
Cumulative monthly total runoff
7000
TIGRIS HADCM3-A2
5000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
500
J
F
M
A
M
J
Months
J
A
S
O
N
0
D
M
N
M
S
O
H
a
2500
3/sn)
(Mm
Cumulative monthly total runoff
3000
2000
1500
1000
500
O
S
M
N
M
H
c
Months
E
K
A
3500
3000
2500
A
S
O
N
D
2000
1500
1000
500
T
A
E
E
K
0
A
c
J
M
F
M
A
J
d
Months
d
TIGRIS HADCM3-A2
4500
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
4000
(Mm3/sn)
0
E
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
4000
Cumulative monthly total runoff
(Mm3/sn)
Cumulative monthly total runoff
3500
A
TIGRIS HADCM3-A2
4500
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
4000
T
b
TIGRIS HADCM3-A2
4500
b
Months
3500
3000
2500
2000
1500
1000
500
0
J
F
M
A
M
J
Months
J
A
S
O
N
D
e
Figure 4. Tigris drainage basin HADCM3-A2 scenario CMTR graphs.
6
J
5. Groundwater potential
In the GRACE approach one of the main
purposes has been the estimation of groundwater reduction rates without actual data.
The authors relate GRACE model results as
a remedy for water scarcity and tension over
trans-boundary waters and give the example
of Euphrates-Tigris region, offering a compelling example of the satellite observations
in providing insight into critical water issue
in regions where hydrological observations
are difficult to obtain. However, uncertainty
gradients in such models may compel and
escalate the water issues in areas without
any ground measurements or reliable methodology.
There are many uncertainties in managing
natural water resources especially in cases
of transboundary groundwater resources because of insufficient and unreliable data and
information availability. An effective management system should include sufficient
and reliable data and information. Among
the data and information sources limitation
of the groundwater aquifer systems, types
of aquifers (unconfined, confined or leaky),
aquitards, aquifer parameters (porosity, storage coefficient, transmissivity, leakage factor) storage volume estimation, groundwater
level measurements.
The land use is not related to infrastructure in Turkey only, whereas each country
(Turkey, Syria and Iraq) has its own pattern
of usage, which may not be entirely dependent on water resources. Only in case of
agricultural land use, such infrastructure
comes into view, but even then the meteorological, climatologic, topographic, fertile
soil coverage factors and rational regional
management practices based on these factors are important.
Paucity of hydrologic data is not only in
the Middle East, but in many places all over
the world. The ground data measurements
should be very helpful in the confirmation
of the satellite based approaches such as
the GRACE mission. Actual groundwater
measurement data are absent or incomplete
in many parts of the world. It is true that
access to such data is under the control of
governments and even the natives may not
be able to obtain. In such situations, satellite
observations of time-variable gravity from
the Gravity Recovery and Climate Experiment (GRACE) satellite mission present a
supportive and valuable tool to represent
gaps of data for water management (Voss
et al., 2013). For reliable and confident results the availability of the ground data is a
prerequisite, but the application of appropriate modeling approaches are also as significant as the data. Global hydrologic and
water resources models in cases of limited
observational data yield surface water discharges with high percentage of error and in
the groundwater estimation such errors are
magnified to even higher levels, and hence,
the uncertainty amounts may lead to preliminary but yet unreliable results. Such uncertain results may even escalate mistrust
between the concerned parts.
The monthly GRACE data are used by
Voss et al. (2013) with respect to the mean
of the study period (7 years). On the other
hand, the GRACE data is filtered for noise
reduction so as to identify the lost signal,
which is more regular. In spatial filtering
usage the radius of influence or the area of
influence should be taken into consideration (Şen, 2009). It is also necessary to use
spatial, temporal or spatiotemporal filtering.
An objective definition of proper infiltration
methodology is necessary for trend removal
from the annual total water storage (mm/
year), which is not possible in the region due
to again data paucity.
NASA Global Land Data Assimilation
System (GLDAS) provided precipitation,
evaporation, streamflow, soil moisture and
7
snow water equivalent, but there is no information about the infiltration, percolation or
groundwater, because it is surface modeling
system. This system overcomes data inaccessibility in a synthetic manner without any
verification and validation even by a single
ground observation. Hence, right at the beginning the reliability of such synthetic data
is questionable.
E (G ' ) 2 = E (S' ) 2 + E (SWE ' ) 2 +
E ( SW ' ) 2 + E (SM ' ) 2 −
2E (S' SWE ' ) − 2E (S' SW ' ) −
2E (S' SM ' ) − 2E (SWE ' SW ' ) −
2E (SWE ' SM ' ) − 2E (SW ' SM ' )
(2)
which can be rewritten succinctly by consideration of the following definitions for the
variance, Var(X), Var(Y); covariance, Cov(X, Y); and the autocorrelation coefficient,
ρxy, between, say, X and Y as,
5.1 Groundwater storage calculation
Eq. (1) is a simple and lump-sum model
of surface modeling system over a large areal coverage (TEWI), where each term on the
right hand side is considered as independent
from others. For instance, it implied that the
SWE does not have any effect on SW and SM.
V(X) = E(X2)-E2(X)
(3)
Cov(X,Y) = E(XY)-E(X)E(Y)
(4)
ρ XY =
Cov( X , Y )
V ( X )V (Y )
=
E ( XY ) − E ( X ) E (Y )
V ( X )V (Y )
=
Surface water altimetry data are obtained
also from Asad and Qadisiyah reservoirs,
which are not natural but artificial lakes and
they may have been regulated during the
study period. So, how could one rely on water
altimetry data from these two reservoirs like
other natural lakes? How could water altimetry data converted to evaporation and water
volumes without knowing elevation-area and
elevation-volume curves, perhaps approximately through assumptions about the lake
topography. If so, there are additional errors
introduced into the overall calculations.
E ( XY )
V ( X )V (Y )
(5)
and
E(XY) = ρXY√V(X)V(Y) = ρXY σX σY
(6)
where σx and σy are the standard deviations
of X and Y, respectively. By taking all of
these definitions into consideration and provided that each variable has Gaussian (normal) probability distribution function (pdf)
one can then rewrite Eq.(2) as,
2
2
2
σ S2 + σ SWE
+ σ SW
+ σ SM
− 2 ρ SSWEσ Sσ SWE −
2 ρ SSW σ Sσ SW
σ GW = − 2 ρ SSM σ Sσ SM −
2 ρ SWESW σ SWEσ SW
− 2 ρ SWESM σ SWEσ SM
− 2 ρ SWSM σ SW σ SM
Groundwater storage change estimations
have gross error in the methodological calculations of Eq. (3), which has expectation
(long-term average) balance as,
E(G') = E(S')₋E(SWE')₋E(SW')₋E(SM') = 0 (1)
(7)
which is the general form of authors’ Eq.
(3). If the correlation coefficients are ignored among four components on the right
hand side of Eq. (7) then one can obtain
their Eq.(3).
By definition
E(S') = E(SWE') = E(SW') = E(SM') = 0
Furthermore, Eq. (3) is an approximation,
where the interdependence of mutual variables is not taken into consideration. In order
to show this point, if both sides of Eq. (3)
are squared and then the expectation operation is applied, the following expression
results.
2
2
2
+ σ SW
+ σ SM
σ GW = σ S2 + σ SWE
(8)
Ignorance of negatively contributing
terms in Eq. (7) and instead use of authors’
Eq. (3) without caring for Gaussian pdf
8
leads to overestimations, which is the case
in the authors’ paper. Furthermore, in their
Eq. (3) all of sudden one-sigma trend error
is used without its definition, reason or relevant explanation.
on many sets of assumptions, model restrictions, data scarcity and methodological incompleteness, and therefore, quantitatively
one cannot believe (there is no place for
belief in science) such results, but perhaps
they can be suggested as scenarios for the
time being. Ground measurement incorporation does not indicate such a case at least inside Turkey according to the climate change
models (Şen et al., 2010).
It is a valid statement that authors’ work
offers an example of a ‘best available’ approach for regions where in situ data are inaccessible, but it cannot be considered for
actual water management and conclusive
inferences due to present shortcomings,
various uncertainties and methodological
assumptions embedded in the study. Such
uncertainties, shortcomings, restrictive assumptions and incomplete terms in the use
of authors’ Eq. (3) are more pronounced
especially in the groundwater calculations.
Declines in the groundwater resources not
only in this study area but in many parts of
the world are common problems mostly as a
result of mismanagement. The depletion in
groundwater resources is quantified by the
GRACE approach as 63% loss change from
2003 to 2009 is over exaggeration. How
could GRACE alone be able to separate
groundwater and soil moisture? Drilling of
thousands of wells is easy, but if their local
management is not cared for scientifically,
this does not mean that the reason is due to
the whole area of Euphrates-Tigris basin.
Both trends in Figure 4 cannot be reliable,
because the duration is very short as 7 years
or even 3 years for the red line in this figure,
whereas proper trend analysis require much
longer durations at least 30 years for normal
and stable statistical trend reliability.
The World Bank Report (2006) highlights
the displacement of hundreds of thousands
of people from Northern Iraq due to lack of
water, which may be an internal problem of
water resources mismanagement, because
Iraq has the biggest per capita per year water amount among the three countries as in
Table 1 (Kolars, 1993). Water quantities per
capita in the three riparian countries to Euphrates-Tigris basin are given in the following table, which indicates that Iraq has the
maximum among the riparian.
Table 1 Per capita per year water
Country
1993
2020
Iraq
2110
950
Turkey
1830
980
Syria
1420
780
The annual per capita water for Iraq is
higher than the other countries, and in the
next decade water decrease in many regions
of world. This point indicates that the three
riparian countries should look for the solution of their common problem through hydro-politics based on scientific indicators
and sound models. On this issue, further developed and rectified GRACE methodology
may support rational, equitable and optimum utilization of the trans-boundary water
management of the Tigris-Euphrates Basin
by considerations of hydro-meteorology,
climatology, soil quality, and hence, actual
needs for each riparian country.
The GRACE data based total water volume loss of about 144 km3 over 7-year period is in gross overestimation and cannot reflect the real situation, but in general, there
is water loss due to climate change, population increase, land use, mismanagements
especially in groundwater exploitation. It is
not possible to state that this rate is alarming
for the region. These are model results based
9
Although international water law does not
provide a guiding principle for trans-boundary management not only in the Tigris-Euphrates basin but in any other drainage basin
in the world, as mentioned above there is unconditional agreement that Turkey continuously releases 500 m3/sec of water to downstream. It is natural that Iraq should receive
only streamflow that remains after appropriations and diversions by Turkey and Syria,
provided that equitable, optimal and rational
bases are agreed by all the countries.
There are many models available in the
literature for effective international water
management strategies including unilateral action of each country or for cooperative
managements as bilateral and trilateral actions (Küçükmehmetoğlu et al., 2010). In
the same work there are many references on
the same line.
The study does not provide unique opportunity, but a supplementary alternative,
because present climate change models indicate that in the eastern Mediterranean region including Tigris-Euphrates basin there
are expected decreasing precipitation trends
not over short durations as several years but
in the long run (IPCC, 2007). Actually, decrease in the precipitation will trigger the
use of groundwater resources exploitation
rate not only in Tigris-Euphrates basin only,
but anywhere in the world with similar impacts of climate change.
After all what have been explained by
the authors holistically over TEWI region
including their confident feelings, assumptions and assertions that GRACE-derived
estimates are accurate, there is not yet well
documented reason for such a conclusion at
least for the Euphrates-Tigris region.
Figure 5 indicates the cumulative monthly precipitation amounts in the Turkish part
of the Euphrates-Tigris basin after an extensive study, which took into consideration
climate change scenario type A2 from the
Max Plank institute in Germany. The climate change downscaling methodology and
software developed by the Turkish Water
Foundation are used to make monthly precipitation and runoff predictions up to 2100
(Şen, 2009; Şen, et al. 2010).
EUPHRATES-TIGRIS BASIN EH4OPYCA2
800
Cumulative monthly precipitation (mm)
Landslides in Iran and likewise in the
central Anatolia are local problems due to
excessive groundwater abstraction without
abiding with water resources management
rules, especially, groundwater recharge-discharge balance rule.
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
700
600
500
400
300
200
100
0
J
F
M
A
M
J
Months
J
A
S
O
N
D
Figure 5 Climate change impact on Tigris-Euphrates basin
in Turkey
It is clear from this figure that there
are natural fluctuations around the average precipitation with worst years monthly
amounts, but on the overall average natural trends appear depending on wet and dry
(drought) appearances.
GRACE model approach is most welcome for water resources management problems, but it needs, as the authors stated,
ground measurements, otherwise the sole
conclusions from this model cannot be regarded as accurate, valid and reliable prior to local verification and validation with
local factual conditions. Besides, Swenson
and Milly (2006) stated that the seasonal
effects of human water management activities and seasonal biomass changes are both
negligible compared to the effect of water
10
storage. GRACE can thus provide global
observations of changes in total water storage averaged over scales of few hundred km
and greater (Wahr et al., 2004; Swenson et
al., 2003). Averaging over such scales cannot be representative of the actual situation,
besides; these are averages for precipitation
only, which cannot be representative for surface water or especially groundwater managements.
Conclusions
Water resources assessment and management can be achieved only through scientific
approaches and methodologies especially in
cases of trans-boundary surface, sub-surface
and groundwater resources. Only science
based methodologies provide a common domain for each riparian otherwise technical
committee meetings without objective and
simple models cannot provide a chance for
joint decision. This is the only way to make
the present evaluations and possible future
scenario predictions that can be criticized,
discussed and wrought into a better jointly
acceptable form. It is the main purpose of
this paper to provide preliminary and basic information and numerical results about
the water resources concerning Euphrates-Tigris basin surface and groundwater
resources. For this purpose after a relevant
literature review global warming effective
climate change impacts on the monthly precipitation amounts and runoff discharges are
given up to 2050. These results are obtained
by the combination of General Circulation
Model (GCM) grid point scenario data combined with national downscaling model for
Turkey.
The groundwater resources assessment
in the region is based on the available information in the literature with some mathematical improvements on the water balance
equations.
11
References
Cooley, j. K., 1984. The War over Water, Foreign Policy, Issue 58, 3-26.
Gleditsch, Nils Petter. (2003) Environmental
Conflict: Neomalthusians vs. Cornucopians. In Brauch, Hans Günter, Peter H.
Liotta, Antonio Marquina, Paul F. Rogers,
Mohammad El-Sayed Selim eds. Security
and the Environment in the Mediterranean: Conceptualizing Security and Environmental Conflicts. Berlin: Springer, pp.
477–485.
Homer-Dixon T 1991 On the threshold: environmental changes as causes of acute conflict
Int. Security 16 76–116.
Homer-Dixon T 1999 Environment, Scarcity,
Violence (Princeton, NJ: Princeton University Press)
IPCC (2007) IPCC Fourth Assessment Report
Working Group I Report “The Physical
Science Basis”. Cambridge University
Press, New York.
Kibaroglu, A. (1998a). International Regimes
for Effective and Equitable Management
and Use of Water Resources: Implications
for the Euphrates-Tigris River Basin, Unpublished PhD Dissertation, Bilkent University, International Relations Department, Ankara.
Kolars, J. F. (1993). Problems of International
River Management: The Case of Euphrates, papers from the Middle East Water
Forum, Cairo, 7-10 February, p. 49.
Küçükmehmetoğlu, M., Şen, Z., Özger, M.
(2010). Coalition possibility of riparian countries via game theory and
fuzzy logic models. Water Resources Research, Volume 46, Issue 12, DOI:
10.1029/2009WR008660.
Swenson, S. C., Wahr, J., and Milly, P. C. D.
(2003). Estimated accuracies of regional
water storage variations inferred from the
Gravity Recovery and Climate Experiment
(GRACE), Water Resources Res., 39(8),
1223, doi:10.1029/2002WR001808.
Swenson, S.C., and Milly, P. C. D. (2006). Climate model biases in seasonality of continental water storage revealed by satellite
gravimetry. Water Resources Res., 42(8),
1-7, doi:10.1029/2005WR004628.
Şen, Z. (1995). Applied Hydrogeology for Scientists and Engineers. Taylor and Francis
Group, CRC Publishers, 496 pages
Şen, Z. (2009). Precipitation downscaling in climate modeling using a spatial dependence
functions. International Journal of Global
Warming, Vol. 1, No. 1, 29-42.
Şen, Z. (2012). Groundwater Risk Management
Assessment in Arid Regions. Water Resources Management, Vol. 26, Issue 15,
4509-4524
Şen, Z., Uyumaz, A., Cebeci, M., Öztopal, A.,
Küçükmehmetoğlu, M., Özger, M., Erdik,
T., Sırdaş, S., Şahin, A. D., Geymen, A.,
Oğuz, S., and Karsavran, Y. (2010). The
impacts of Climate Change on Istanbul
and Turkey Water Resources. Istanbul
Metropolitan Municipality, Istanbul Water
and Sewerage Administration, 1500 p.
United Nations General Assembly. 1997. General Assembly Adopts Convention on Law
of Non-Navigational Uses of International Watercourses, Press Release GA/9248,
May 21, 1997.
Voss, K. A., Famiglitti, J.S., Lo, M., Linage,
C., Rodell, M., and Swenson, S.C., 2013.
Groundwater depletion in the Middle
East from GRACE with implications for
transboundary water management in the
Tigris-Euphrates-Western Iran region.
Water Resour. Res., Vol. 49, 904–914,
doi:10.1002/wrcr.20078, 2013
Wahr, J., S. Swenson, V. Zlotnicki, and I. Velicogna (2004), Time-variable gravity from
GRACE: First results, Geophys. Res. Lett.,
31, L11501, DOI:10.1029/2004GL019779
World Bank (2006). Iraq: Country Water Resource Assistance Strategy: Addressing
Major Threats to People’s Livelihoods.
Report No. 36297-IQ. Washington, D.C.:
Mr. Ahmed Shawky M. Abdel Ghany
12
Tüm Su Vakfı bültenlerini http://bulten.suvakfi.org.tr adresinden bilgisayarınıza indirebilirsiniz.
SU VAKFI
Libadiye Cad. Doğanay Sokak No:6 Kat:4 Üsküdar İstanbul
Tel: (216) 412 3383 - Faks: (216) 412 3390
[email protected] - www.suvakfi.org.tr