Groundwater Degradation and Sustainability of the Erbil Basin, Erbil, Kurdistan Region, Iraq By RUBAR DIZAYEE Bachelor of Science, 2010 Salahaddin University Hawler, Kurdistan Submitted to the Graduate Faculty of the College of Science and Engineering Texas Christian University Fort Worth, Texas in partial fulfillment of the requirements for the degree of Master of Science August 2014
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Groundwater Degradation and Sustainability of the Erbil
Basin, Erbil, Kurdistan Region, Iraq
By
RUBAR DIZAYEE
Bachelor of Science, 2010
Salahaddin University
Hawler, Kurdistan
Submitted to the Graduate Faculty of the
College of Science and Engineering
Texas Christian University
Fort Worth, Texas
in partial fulfillment of the requirements
for the degree of
Master of Science
August 2014
ii
ACKNOWLEDGEMENTS
This thesis would not have been possible without Becky Johnson’s support. I am grateful to her
for being my thesis supervisor. I thank Dr. Michael Slattery and Mrs. Tamie Morgan for their
contribution to my thesis. I am grateful to Dr. Helge Alsleben for his serious effort in providing
me with valuable feedback. I would also like to thank Dr. Steve Sherwood from TCU writing
center for his support in finishing this thesis. My gratitude goes to Mr. Mohammed Ahmad and
Dr. Imadaldin Hassan for providing me with information during my research. I also would like to
thank my friends Sebar Muhsin and Mahmood Mustafa for all the help they provided during this
research. My greatest appreciation goes to my parents for always believing in me and for their
continuous support.
iii
TABLE OF CONTENTS
LIST OF FIGURES ....................................................................................................................... vi
LIST OF TABLES ........................................................................................................................ vii
Figure 11: Depth map for Alluvium aquifer ................................................................................. 44
Figure 12: Depth map for Bakhtiary aquifer................................................................................. 45
Figure 13: Location map of Erbil Basin showing alluvium profile along A-A’ and B-B’ ........... 49
Figure 14: NW-SE cross section along (A-A’) of alluvium aquifer ............................................. 50
Figure 15: NW-SE cross section along (B-B’) for Alluvium aquifer. .......................................... 51
Figure 16: Location map of Erbil Basin showing Bakhtiary profile along A-A’ and B-B’ ......... 52
Figure 17: NE-SW cross section along (A-A’) of Bakhtiary aquifer. .......................................... 53
Figure 18: NW-SE cross section along (B-B’) of Bakhtiary aquifer ............................................ 54
Figure 19: Map of the location of the meteorological stations in the study area. ......................... 55
Figure 20: Relationship between average annual temperature and average annual evaporation in
the study area. ............................................................................................................................... 58
vii
LIST OF TABLES
Table 1: Litho-stratigraphy of the aquifer systems in the Low Folded Zone of the Taurus- Zagros
series ............................................................................................................................................. 12
Table 2: Details about the 36 selected wells ................................................................................. 28
Table 3: Details about the 18 wells. .............................................................................................. 36
Table 4: Average annual precipitation for the years 2008 to 2012 ............................................... 61
Table 5: Results of the Calculations ............................................................................................. 62
1
Chapter One: Introduction
1.1. Overview of project
The Erbil Province is one of the most important agricultural regions in Iraq. The study
area contains the town of Erbil, the highly populated governorate in the region of intensive
irrigated agriculture area. People use groundwater annually for irrigation, agriculture, and
drinking. This water comes from drilled wells since groundwater is available throughout the
whole region. Surface water sources are very often unusable for human consumption due to a
lack of management and strategic planning. Consequently, groundwater plays an important role
for both irrigation and basic daily uses. Previous researches do not asses the sustainable use of
groundwater on a large scale; however, sustainability and contamination issues are major
problems in the Erbil Region. The study of the Erbil Basin was selected because 1) it contains
the highly populated Erbil City, 2) the water table has decreased sharply and a number of wells
have dried up in the last few years, and 3) desertification is increasing and precipitation is
decreasing in the area.
The Erbil Province is located in northern part of Iraq and covers an area of 15,074 km2
(3.5% of Iraq). It is the fourth largest Iraqi province after Bagdad, Basra, and Mosul (NCCI). The
province is bounded by Kirkuk to the south, Salah al-Din to the southwest, Ninewa to the west,
Dahuk to the northwest, and Sulaymaniyah to the east (Figure 1). The provinces of Kurdistan
Region (Erbil, Dahuk, and Sulaymaniyah) are geologically, hydrogeologically, and climatically
similar.
2
Fig
ure
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Loca
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rbil
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.
3
The Zagros Mountains represent the main topography to the north and northeast of the
Kurdistan Region, reaching an elevation of 3,600 meters above sea level, whereas the Tigris
River plains (alluvial plains) are in the south of the region (Hameed, 2013). The vicinity of Erbil
province is comprised of mountainous uplands and fertile plains. Over 34% of the Kurdistan
Region is farmland used by people for agricultural purposes, while the rest consists of pasture,
forests, and urban land. In the Erbil province, 41% of the area is arable land and 59% is non-
arable land. The Erbil Basin is one of the most important basins in the Kurdistan region in terms
of adequate quantity and quality of groundwater as well as fertility of the land. The development
of the Erbil Basin has long been debated because there are unique features that separate it from
other basins, such as its geologic structure, stratigraphic relationships, and the geomorphological
setting of the region (Hameed, 2013).
Topographically, the Erbil Basin area is generally undulating with gentle to moderate to
very steep slopes. The plain of the Chai Siwasor, which stretches from Erbil to the Greater Zab
River, is an exception and is a nearly flat region without much topography (Ur et al., 2013). The
Erbil Basin is geomorphologically and geologically diverse, containing a range of river valleys,
flat alluvial plains, rolling gravel hills, and the Zagros foothill zones. Numerous large anticlines
and synclines with axis mainly oriented NW-SE parallel to the main Zagros orogen helped
producing the orientation of drainage patterns (Jassim and Goff, 2006). Also, the regional fault
systems are associated with intensive uplift. The Greater Zab River bounds the Erbil Basin to the
north-northwest, and Lesser Zab River bounds the basin to the south-southeast. The watershed
between the Erbil Plain and the Valley of Shalga River defines the eastern boundary of the basin.
The southwestern limit of the basin is the first long anticlinal hill that separates the Erbil Plain
from the Makhmur Plain, whereas the northeastern limit is the valley of the Bastora (Jassim and
Goff, 2006; Ur et al., 2013).
4
The overarching goals of this study are to determine the feasibility of groundwater use
and its sustainability for the entire Erbil Basin. This study addresses the following questions: (1)
What is the geometry and physiography of the basin? (2) Does a groundwater deficit exist and, if
so, how does it affect the various sub-basins in the Erbil Basin? (3) What is the overall
sustainable use of the groundwater within the aquifer systems across the Erbil Basin? The
hydrogeological study of the Erbil Basin assesses the availability of the groundwater resources in
the Erbil Basin for the development of irrigation, agriculture and drinking purposes.
Furthermore, the study focuses on the characteristics of the two main aquifers (alluvium and
Bakhtiary Formation) throughout the whole Erbil Basin and its sub-basins. The study also
includes an attempt to quantify the sustainability of these aquifers within the sub-basins.
This research is based on raw well data for five consecutive years (2008, 2009, 2010,
2011, and 2012). Data include static groundwater levels, dynamic groundwater levels, ground
surface elevations, depth to water, total depths of the wells completed in the two main aquifers,
and soil types. In addition, a climate data set includes precipitation and evaporation data. These
data are used to investigate and better understand the groundwater availability across the entire
basin. The author used climate, water well, and formation data to conduct an analysis of
groundwater levels, aquifer storage, and aquifer recharge from precipitation, and compares
groundwater withdrawals to recharge rates to estimate sustainable groundwater use in the Erbil
Basin.
5
1.2. Previous Studies:
There is a definite lack of scientific study and papers for the Erbil Basin. Below are the
papers that the author depended on while conducting this study:
Jawad and Hussien (1988) studied the groundwater monitoring network rationalization in
the Erbil Basin by applying a multivariate analysis approach to rationalize a piezometric
approach on a network of fifteen wells monitored for about three years. The purpose of
their study was to measure the annual changes in the aquifer storage and understand the
aquifer conditions in terms of recharge and discharge, by dividing the aquifer into a
number of zones and analyzing the aquifer condition in each zone separately.
Hassan (1998) studied the groundwater conditions in the Erbil Basin. The author
proposed a method (maximum water surplus method) for calculating the average amount
of infiltration from precipitation, and surface runoff. The study also included an analysis
of hydro-chemistry and hydro-geochemistry of the groundwater in the region and
considered that groundwater in the area is very suitable for industry, irrigation, and
domestic purposes. Since in Erbil people depend mainly on groundwater for all aspects of
life, Hassan (1998) calculated water population balance in the area to find the water
demand per capita in winter and summer seasons.
Al-Tamir (2008) conducted a study on groundwater quality variation in the Erbil City by
applying principle components analysis technique (PCA) to define the factors responsible
for the variance in groundwater quality and pollution. The author concluded that the
variance in the groundwater quality is as a result of agricultural pesticides and herbicides,
human activities, and rock dissolution.
6
Hameed (2013) conducted a study on water harvesting in the Erbil Territory. The study
focused on identifying suitable sites for water harvesting by using geographic
information system (GIS) and multi criteria evaluation (MCE). The author suggested a
number of micro and macro catchments depending on data such as soil texture, slope,
rainfall data, land use/cover, and drainage network. The author concluded that suitable
sites for rainwater harvesting are 36% of the total area of the region.
7
Chapter Two: Geology, Hydrogeology, Climate, Soil, and Population
2.1. Kurdistan Region
2.1.1. Tectonic Framework of Iraq and Kurdistan Region
The Zagros Belt in Northern Iraq is an example of a geologically recent Tertiary orogen
with an earlier obduction-subduction tectonic history (Numan, 1997; Jassim and Goff, 2006).
The tectonic activity along the Zagros Belt has been long-lived and started in the Late-
Cretaceous time (Numan, 1997); however, the final geometry developed during Miocene-
Pliocene time. The Zagros Mountains formed as a result of the collision of the Arabian and
Eurasian plates, where the Arabian plate was subducting underneath the Eurasian plate until it
reached a collisional stage (Jassim and Goff, 2006). This collision created a fold-thrust belt.
The Zagros orogen in the Kurdistan Region of Iraq is divided into stable and unstable
shelves; the stable shelf has a thin sedimentary cover with no significant folding, whereas the
unstable shelf has a thick and folded sedimentary cover and the folding increases toward the
northeast (Al-Juboury, 2012) (Figure 2). The unstable shelf is divided into four NW-SE striking
tectonic elements (Numan, 1997; Jassim and Goff, 2006): Foothill Zone (Low Folded Zone),
High Folded Zone, Imbricate Zone, and Zagros Suture Zone (Figure 2) (Jassim and Goff, 2006).
8
Figure 2: Tectonic map of Kurdistan Region (modified from Jassim and Goff, 2006).
The Erbil Basin area lies in the Low Folded Zone of Northern Iraq. Buday (1980)
introduced the Low Folded Zone as a tectonic unit, which has limited tectonic activity.
Anticlines and narrow synclines are dominated by open folds that have wavelengths ranging
from 5 to 10 km. The areal extent of the Erbil Basin covers a wide syncline bounded by the
Permam Dagh anticline in the NE and by the Kirkuk anticlinal structure in the SW. According to
Buday and Jassim (1987), the synclinal area between these anticlines represents the middle part
of the Erbil plain, which consists of several sub-basins (northern, central, and southern) (Bapeer
9
et al., 2010). The Erbil Basin is getting deeper toward SSE, where the antiforms and synforms
disappear and the thicknesses of the formations are increasing. In contrast, the basin gets
shallower towards the NNE, where the antiforms and synforms are more abundant and
topography increases as does tectonic activity (Figure 3).
Figure 3: Regional hydrogeological cross section (Choman-Erbil). Modified from
Stevanovic and Iurkiewicz (2009)
2.1.2. Stratigraphy
The stratigraphy of the area is characteristic of Iraq’s Zagros belt (Figure 4) (Bellen et al.,
2005). The sedimentary succession is possibly more than 10 km thick and quite probably begins
with late Precambrian formations. This layer is overlain by a Palaeozoic–Lower Mesozoic
succession that is several thousand meters thick (Numan, 1997; Jassim and Goff, 2006). Steady
and slow subsidence throughout the Mesozoic allowed widespread deposition of shallow marine
sediments on a wide epeiric carbonate platform (Dunnington, 1958). From mid-Jurassic to Late
10
Cretaceous faulting formed intra-shelf basins with clastic input from the west. Cretaceous
deposition was periodically interrupted by nondeposition and erosion due to localized
reactivation of faults during the Zagros orogeny. During Palaeocene-early Eocene time, a NW-
SE-trending, deep open marine basin developed to the south through central and eastern Iraq in
which the clastics (mainly shale) of the Kolosh Formation were deposited. Shallowing of this
basin and its isolation from clastic input gradually introduced limestone into the upper part of the
Kolosh Formation, and further shallowing introduced red beds and marls in mid-late Eocene
times, when sedimentation was controlled by a shelf isolating this lagoonal area. The Pilaspi
Formation represents a lagoonal facies. The late Eocene unconformity at the top of the Pilaspi
Formation is the result of a marine regression.
Figure 4: Tertiary and Quaternary rock units in Iraq. Modified from Bellen et al. (2005)
AGES
11
During the late Miocene, the Lower Fars Formation, which is dominated by mudstone,
shale and sandstone, formed as a result of erosion of mud and sand from nearby hills in a
terrestrial environment (Al-Tamir, 2008; AL-Kubaisi, 2008). The remainder of the surface
geology comprised of fluvial sandstones and muds passing upward into the coarse fluvial
conglomerates of the Bakhtiary Formation (see below). The Pleistocene period was characterized
by coarse pluvial and fine inter pluvial pebbly sand and silty sediments (AL-Kubaisi, 2008) and
the deposition of recent alluvium (see also below) is also terrestrial.
2.1.2.1. Bakhtiary Formation
The Bakhtiary Formation crops out at the surface near the southern end of the Bastora
area, on the limbs of Permam anticline located in the north of Erbil Province, and both eastern
and western sides of the basin, which is close to the recharge and discharge zones of the study
area (Habib et al., 1990). It consists of thickly-bedded conglomerates, sandstones and shale and
is considered Pliocene age. The formation is overlain by Quaternary terrace gravels in the valleys
or alluvium (Bellen et al., 2005). The Bakhtiary Formation covers more than 80% of the study
area. The thickness of the Bakhtiary Group (Upper and Lower Bakhtiary) varies (Al-Tamir,
2008), but several studies have shown that the thickness of this formation reaches over 1,800
meters at the Erbil Plain (Jawad and Hussien, 1988).
2.1.2.2. Pleistocene units and Alluvium
The Quaternary deposits are common over a wide range of the Erbil Basin area.
Pleistocene deposits, which rest on a Pliocene Bakhtiary Formation (Table 1), consist mainly of
soils, gravels, and conglomerates with some sands, clay, and silt. The youngest deposits consist
of river terraces deposits, alluvial fans, slope deposits and flood plain deposits (Jassim and Goff,
12
2006). The thickness of these deposits varies; however, it can exceed 100 meters in some
locations across the basin. The nature of these coarse-grained, unconsolidated materials makes
them ideal reservoirs for groundwater. The coarse sediments of the alluvial fans play a vital role
in shaping and generating confined aquifers within the basin. The coarse alluvial deposits consist
of fine-grained clay interbedded with sandy silty layers that amalgamated with pebbly, gravelly
strata. Ghaib (2004, 2009) estimated the water table level and thickness of the alluvial deposits.
The thickness of the alluvium might reach up to 150 meters, especially at the Bastora area near
the northern boundary of the Erbil Basin.
Table 1: Litho-stratigraphy of the aquifer systems in the Low Folded Zone of the Taurus-
Zagros series (from Stevanovic and Markovic, 2004)
Age Formation Lithology
Thickness
(m)
Water bearing
characteristics
Quaternary Pleistocene
to recent Alluvium
Gravel, clay,
and sand 10-150
Hydraulically
connected;
from one
aquifer system
in the Low
Folded Zone
Neogene
Pliocene
Upper
Bakhtiary,
Lower
Bakhtiary,
Mukdadia
Conglomerates
and Claystone,
partly
Sandstone and
Siltstone
>2,500-3,000
Miocene
Upper
Fars,
Lower Fars
Mainly
sandstone and
Evaporites,
and some
Conglomerates
L. Fars:
400- 900
U. Fars: 500
Low
groundwater
yield with
acidic or salty
water
13
2.2. Erbil Basin
The largest reservoir for groundwater in the Erbil Province is the Erbil Basin, also known
as Dashty Hawler Basin. The Erbil Basin covers an area of 3,200 km2 and has a depth of
approximately 800 meters. This basin is one of the most important groundwater basins in the
Middle East because of its nearness to the surface, not to mention the quantity and quality of its
water (Ahmed, 2009). The groundwater within the Erbil Basin generally flows from northeast to
southwest. A groundwater divide within the basin directs flows toward either the Greater Zab
River to the north-northwest or the Lesser Zab River to the south-southeast. The groundwater of
the Erbil Basin contains small amounts of soluble salts and harmful ions that could have negative
impacts on human health (Internal report directorate of groundwater-Kurdistan Region, 2012).
In general the Erbil Basin is divided into three sub-basins, which include the Northern
(Kapran) sub-basin, the Central sub-basin, and the Southern (Bashtapa) sub-basin (Figure 5)
(Habib et al., 1990). Researchers based this division on hydrogeological characteristics obtained
from deep wells, previous groundwater studies, and water quality (Ahmad, 2002). Sub-basins are
separated by minor surface and subsurface structures. Other areas in the basin include Shalga and
Bastura, but whether these belong to the Erbil Basin proper is debated.
14
Figure 5: Geological map of Erbil Basin with the sub-basins labeled. Modified from
Hameed (2013)
2.2.1. Northern sub-basin (Kapran)
This sub-basin has an area of 915 km2. The uppermost part of this sub-basin, which is
located near the foothill zone of the Zagros Mountains, consists of Bakhtiary Formation. A few
meters of alluvial deposits overlie the Upper Bakhtiary Formation in the lower part of this sub-
15
basin. In some locations, the thicknesses of alluvial deposits reach 50 to 60 meters. Both the
alluvium and the Bakhtiary aquifers are inter-granular and serve as groundwater-bearing units
(aquifers) with no aquitards or aquicludes between the two formations. According to records
from numerous deep wells, the Bakhtiary aquifers lithologically are composed of gravel, sand,
silt, conglomerate, and clay beds, whereas alluvium aquifers consist of interbedded sand, silt,
clay, and gravel (Ahmad, 2002).
Generally, Bakhtiary and alluvium aquifers are unconfined, meaning that precipitation
infiltrates directly into these aquifers, but in some parts of the study area, because of a covering
of thick clay, the aquifers become semi-confined or confined (Jawad and Hussien, 1988). In
normal conditions, the deep wells will be artesian. In the confined portion of the aquifers,
groundwater occurs at depths of approximately 40 meters below ground surface (bgs) and the
wells are not artesian. The total depths of deep wells drilled into the Kapran sub-basin from 1977
to 1989 ranged from 80 to 150 meters bgs, with total depths of more recent wells (1990 to 2002)
ranging from 160 to 200 meters bgs (Ahmad, 2002).
2.2.2. Central sub-basin
This sub-basin has an area of 1400 km2. The formations in this sub-basin are the Upper
and Lower Bakhtiary Formation and alluvium. The upper part of the Bakhtiary Formation
consists of gravel, sand, clay, and conglomerate strata. However, in some of the deep wells in the
lower Bakhtiary Formation consists of thin beds of gravel, sand, or conglomerate. The materials
of alluvium aquifers are the same as the Bakhtiary Formation, with the exception that they
contain silt in between the other layers instead of multiple clay layers. The discharge rates of
wells in this sub-basin range between 1 to 2 l/s (Ahmad, 2002).
16
2.2.3. Southern sub-basin (Bashtapa)
The Bashtapa sub-basin has an area of 885 km2 and is mostly dominated by the Upper
Bakhtiary Formation. Two different types of aquifer systems, the unconfined and semi-confined
aquifers, characterize this sub-basin. The semi-confined aquifers of this sub-basin consist of silty
materials (silty clay, sandy clay) that are interbedded with thin fine-grained sandstone strata,
amalgamated with clay layers, whereas the unconfined aquifers mainly consist of interbedded
clay beds with some silt or silty clay (Ahmad, 2002).
2.3. Challenges of the sub-basins and legitimacy of the distances between drilled wells
The regulatory principles of drilling water wells are not well developed in the region, and
the implementation and enforcement of the rules and regulations to foster production of water
resources still present fundamental issues in this region. Numerous studies have been done by
different organizations to address these issues; few of them have touched on the major problems
created by a lack of management. The lack of regulation has resulted in wells being drilled in
close proximity to each other, closer than new regulations permit, and the aquifer is also tapped
by numerous unpermitted (illegal) wells.
2.3.1. Northern sub-basin (Kapran)
According to a study done by the Furat Center and adopted by the Ministry of
Agriculture and Water Resources, the distance between wells in this sub-basin should not be less
than 300 meters and the number of drilled deep wells should not exceed 225 wells in the entire
sub-basin. However, the results of the Furat Center’s study show that the current distance
between wells is 450 meters, while the number of drilled wells is 1,074. Furat Center research
indicates that the distance between the wells is adequate, but the number of drilled wells far
17
exceeds the number recommended by the Furat Center. The 1,074 drilled wells also does not
include wells drilled by pile equipment: mechanical devices used to drive piles (poles) into soil
to provide foundation support for buildings or other structures and not for drilling water wells
(Internal Report Directorate of Groundwater-Kurdistan Region, 2012). To get control over the
illegal well drilling, the Kurdish Government forbade drilling wells by pile equipment on 22nd
August 2010 (zarikrmanji.com), aiming to make the aquifers more efficient and faster in
recharging the groundwater.
2.3.2. Central sub-basin
The studies done in this sub-basin by the Furat Center show that the distance between
wells in this sub-basin should not be less than 400 meters and the number of drilled deep wells
should not exceed 738 wells in the entire sub-basin. In fact, the results of the Furat Center’s
research indicate that the well distance in this sub-basin is 600 meters and the number of drilled
wells is 3,149, which exceeds the optimum number of wells supposed to be present by 2,411.
Most of the wells drilled for agricultural purposes are located in this sub-basin, which causes a
real possibility of groundwater contamination by fertilizers used for agricultural purposes
(Internal Report Directorate of Groundwater-Kurdistan Region, 2012).
2.3.3. Southern sub-basin (Bashtapa)
The maximum distance between water wells in this sub-basin, according to the Furat
Center, should not be less than 500 meters and the number of drilled deep wells should not
exceed 500 in the entire sub-basin. The results of the Furat Center’s research shows that the
distance between wells is 550 meters and number of drilled wells is 583. However, most of the
18
wells drilled by pile equipment (not counted in the 583 drilled wells) are located in this sub-basin
(Internal report directorate of groundwater-Kurdistan Region, 2012).
2.4. Climate
The Erbil Province generally has a varied climate and is classified into two climatic
regions. A Mediterranean climate region with an average annual rainfall of 600 to 800 mm
characterizes the north and northeast parts, whereas a warm climate region with an approximate
average annual rainfall of 500 mm characterizes the south and southwest parts of the Erbil
Governorate (Hameed, 2013). It is cold and snowy in the winter, and hot and dry in summer.
January is the coldest month in the region; the average winter temperature for the Erbil Province
is 7.9 °C (Hameed, 2013). The land topography varies from a mountainous and semi-
mountainous region to hilly and plain lands, all of which impact the influence of precipitation.
The plains are characterized by a semi-arid climate. Precipitation occurs from October to May,
and decreases from northeast toward southwest in the region, which means the northeastern parts
get higher amounts of precipitation than the southwestern parts. In the Erbil Province, the
quantity of rainfall is between 200 mm/year in the south and 1,200 mm/year in the north, with an
annual average of about 700 mm/year (Figure 6). Rainfall is one of the most important climatic
factors, and it changes within very short periods of time (UNDP, 2011).
19
Figure 6: Spatial distribution of average yearly rainfall in the study area. Modified from
Hameed (2013).
2.5. Soils
Based on the geographical location, soils in the area vary in depth. For example, soils are
shallow in the north and northeast (mountainous region), whereas the soils are deep and have
good texture in the south of the Erbil Province (the valley and plain lands). Soils in the southern
part of the area are some of the best soils for agriculture and include chestnut soils, dark brown
soils, and black soils. The semi-mountainous areas and most plains are covered with red and
brown soils. Overall, various zones with different types of soils have been identified in the Erbil
Province (Figure 7) (Hameed, 2013).
20
2.6. Population
According to the general Iraqi census, the population of Erbil was 770,439 in the census
of 1987. Starting in 1991, the Kurdish authorities in the three Kurdish provinces did a combined
census. The province’s population numbered 1,095,992 in 1997, 1,315,239 in 2003, and
1,542,421 in 2008 (Internal report directorate of groundwater-Kurdistan Region, 2012).
Population in the Erbil Province has now reached 1.9 million. The population increase indicates
that Erbil grows by 2.9 percent on an annual basis (Erbil Governorate, 2012).
There are significant differences when comparing data from the census and the water
resources management. Demand for water is twice as high as the demand in the 1980’s. Besides
the increase in population, water demand dramatically increased for industry, agriculture, and
Figure 7: Soil types in the Erbil Province. Modified from Hameed (2013).
21
domestic use. At the same time, drought has hit the region. The first drought period started in
1999 and lasted for four years until 2003, while the second drought period started in 2008 and
lasted into 2009 further training the water resources.
22
Chapter Three: Objectives and Methodology
3.1. Objectives
Datasets for water wells and climate from 2008 to 2012 were obtained from the Ministry
of Agriculture and Water Resources of the Kurdistan Regional Government, Iraq. The use of
these data was challenging since there was a lack of details that cover all of the overarching
objectives and to answer all of the questions (see below). However, to reach a certain level of
understanding to the addressed hydrological issues in the Erbil Basin, and to tackle and minimize
the concerns of water users in the Erbil Basin, including water resources deficits, drought,
groundwater overexploitation and mismanagement of the extracted groundwater used, several
objectives are proposed:
1. To obtain, compile, and analyze the available geology, climate, and well data for the
Erbil Basin. This is the first such study conducted in the region at basin scale. A large
portion of this work involved an intensive and complicated research effort to obtain
and integrate the data.
2. To document and quantify the rate of groundwater level changes in the Erbil Basin,
from 2008 through 2012 using the available well data.
3. To analyze the sustainability of the groundwater resources within the Erbil basin based
on the estimated rates of groundwater changes.
3.2. Methodology
Datasets for water wells and climate from 2008 to 2012 were obtained from the Ministry
of Agriculture and Water Resources of the Kurdistan Regional Government, Iraq. The water well
dataset contained the following information for most, but not all, of the wells:
23
Year that the information was collected (called “survey date” for the purposes of
this study)
Well coordinates (latitude and longitude)
Well location (name of basin)
Ground surface elevation
Total depth of the well
Depth to static and dynamic water levels
Name of producing formation (missing for the majority of wells)
Yield
Well names
The climate dataset contained the following information:
Monthly rainfall data (from 1941-2012)
Air temperatures
Relative humidity (in %)
Precipitation (both rainfall and snowfall)
In addition, the Ministry provided a dataset of 18 wells for which water level measurements were
obtained in the years 2001 and 2010. The following data for these 18 wells were available:
Water level data for 2001 and 2010
Well location (name of basin and sub-basin)
Well names
Several programs were used to perform the data analysis including Microsoft Exceltm
,
ESRI ArcGIS 10.1 (Geographic Information Systems), Blue Marble Geographics Global Mapper
13, Rockworks 15, and Adobe Illustrator CS6.
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3.2.1. Manipulation of the Dataset
3.2.1.1. Survey Date
The well data measurements in the Kurdistan Region are collected only once per well
resulting in only one data point for use in this project. The provided well data had not been
sorted according to the survey date (period during which the information about the wells was
collected). The author sorted the wells according to their survey dates; the collected data
consisted of wells surveyed over five years 2008 through 2012.
Unfortunately, the water level measurements were not conducted on the same dates or
even the same years; therefore, the analyses of these data represent overall trends in water levels
for the aquifers, not a precise calculation for a specific date.
3.2.1.2. Well Locations and Coordinates
The Kurdistan Ministry of Agriculture and Water Resources provided a well data set that
consisted of 6,974 wells located in different basins in the province. Wells that did not belong to
the Erbil Basin according to the basin location data (which indicated location of each well) were
discarded; this process reduced the number of the wells from 6,974 to 2,050.
The Latitude /Longitude coordinates for each well were plotted for the 2,050 wells in the
Erbil Basin using ESRI ArcMap 10.1 to find their exact location in the basin. A number of the
wells had missing or inaccurate coordinates. Wells whose location did not plot within the Erbil
Basin were discarded.
Besides missing or inaccurate coordinates, the datasets for some of the wells were also
missing fundamental data for this research, including the survey date, depth where water was
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first encountered while drilling, depth of water table, elevation above sea level, static and
dynamic water levels, characteristics of the aquifer types (confined, semi-confined, or
unconfined), piezometric surface of groundwater, and well yield. By discarding the wells for
which the required information or the latitude and longitude were lacking, the number of wells
included in this study was reduced to 995.
Using Blue Marble Global Mapper to plot the wells on a base map of the Erbil Basin
delineating the sub-basins (Al-Tamir, 2008), each of the 995 wells were classified according to
their location by sub-basin name. Documenting the sub-basin for each well location is important
as the drilling regulations differ in each sub-basin. Using Global Mapper, the distances between
wells were determined to compare the actual distances to the legally permitted distances in each
sub-basin. This documentation was used to determine the legality of the wells in the Erbil Basin.
3.2.1.3. Converting Depths to Elevations
The static to dynamic water levels were converted using the ground surface elevations
and depth-to-water measurements provided in the well dataset. The total depth of the well, depth
to static water level, and depth to dynamic water level were subtracted from the ground surface
elevation to convert depth measurements to elevations.
3.2.1.4. Estimate of Water Producing Formation
Among the 995 wells, only 409 wells had formation information provided in the dataset;
therefore, the author estimated the formation information for the remaining 586 wells by
applying two methods:
(1) Personal contacts with professors Kanar Hamza, Mohammed Ahmad, and
Imadaldin Hassan, who have knowledge about the formations of the area and their