Artificial Recharge of Groundwater by Injection Wells (Case Study)

Abstract

The urgent and growing human need for water resources around the world, particularly in arid and semi-arid regions, has encouraged the search for new ways to store and reuse both ground and surface waters. This study deals with a method of using the injection wells to replenish groundwater resources and reuse it in dry seasons. According to an availability of recommended potential for successful artificial recharge projects. A two-dimensional numerical based model named as Groundwater Modeling System is applied to simulate the flow system of a confined aquifer in the city of Karbala southwest of Iraq. Topredict the behavior of the aquifer over a planning horizon of one year two steps are used. The First step includes of operating 75 existing wells, a continuous decline of groundwater levels will occur if the model is run without recharging the aquifer and an average decline of the head is of about (10 m). In second step an application of artificial recharge by suggesting a system of 30 wells is done, and the case is reversed though raising the levels of ground water. The existence of Rashidiya River and Razzaza drains beside the study area can be considered as the recharge sources. The outcome of such condition revealed the possibility of draw up the water table level in the study area to the 20 m depth after one year of operating the well system at a rate of 1000 m3/d from each well.

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Vol.06,Issue.31
October-2017,
Pages:6193-6196
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Artificial Recharge of Groundwater by Injection Wells (Case Study)
DR. IBTISAM R KARIM1, ALI MAHDI ABD ALI2
1Dept of Building & Construction Engineering, University of Technology, Baghdad, E- mail: m_bajalan@yahoo.com.
2Dept of Structural and Water Resources Engineering, University of Kufa, Engineering College, Najaf, Iraq,
E-mail: amahdi077@gmail.com.
Abstract: The urgent and growing human need for water resources around the world, particularly in arid and semi-arid regions,
has encouraged the search for new ways to store and reuse both ground and surface waters. This study deals with a method of
using the injection wells to replenish groundwater resources and reuse it in dry seasons. According to an availability of
recommended potential for successful artificial recharge projects. A two-dimensional numerical based model named as
Groundwater Modeling System is applied to simulate the flow system of a confined aquifer in the city of Karbala southwest of
Iraq. Topredict the behavior of the aquifer over a planning horizon of one year two steps are used. The First step includes of
operating 75 existing wells, a continuous decline of groundwater levels will occur if the model is run without recharging the
aquifer and an average decline of the head is of about (10 m). In second step an application of artificial recharge by suggesting a
system of 30 wells is done, and the case is reversed though raising the levels of ground water. The existence of Rashidiya River
and Razzaza drains beside the study area can be considered as the recharge sources. The outcome of such condition revealed the
possibility of draw up the water table level in the study area to the 20 m depth after one year of operating the well system at a
rate of 1000 m3/d from each well.
Keywords: Groundwater, Artificial Recharge, Injection, GMS.
I. INTRODUCTION
Artificial recharge of ground water by recharge wells
(i.e.( "aquifer re-injection" is the most credible alternative
water resource (Todd 2007). It is the process of injecting or
“recharging" water into the ground in a controlled way, by
means of special recharge wells. The water is pumped from
the ground surface to the recharge location. Water may have
to the treated prior to recharge, in order to reduce the risk of
clogging of recharge wells. The injection wells have
advantageous when land is scarce and it will adopt this
technique in the modern city of Karbala southwest of Iraq
for the storage of surface water in the aquifer to supplement
groundwater supplies and prevent the drain. Modern city of
Karbala is characterized by the presence of water runoff in a
short period of time (Al Basrawi, 1996). Such quantities are
generally lost and thus ought to be collected for later use
after being artificially recharged into aquifers to meet future
water demands. The region needs to developits activity by
gradually raising of groundwater levels in order to courage
ofinvestment projects in the region.
II. DESECRATION OF THE STUDY AREA
The study area located in Karbala governorate, bounded
by Al- Razzaza Lake north and the AL Rushdia River north-
northeast, a scarp called Tar Al-Sayyed west, Al-Najaf city
south and by Karbala city east as shown in Fig.1 .The study
area of 4294.75 km2is considered one of the important part
in the city of Karbala, because there are many industrial and
agricultural investment projects.
Fig.1. Location of the study.area.
III. MATERIAL AND METHODOLOGY
The methodology of work can be divided into two
categories, as shown in Fig.2:

DR. IBTISAM R KARIM, ALI MAHDI ABD ALI
International Journal of Scientific Engineering and Technology Research
Volume.06, IssueNo.31, October-2017, Pages: 6193-6196
Firstly: The data of the investigated area was providing by
the General Administration of groundwater in Karbala
governorate , which includes climate data(1), topographic
maps(1), hydrological data(2) for 75 existing wells and
general information about the area.
Secondly: State the suitable software for building up the
study model such as Groundwater Modelling System (GMS)
software. The GMS is used to simulate the steady and
unsteady states of flow based on two-dimensional finite
difference techniques.
Fig.2. Flow chart of modelling methodologies.
IV. DEVELOPMENT OF THE GROUNDWATER
SYSTEM MODEL
The primary source of groundwater to the model is the
recharge from injection wells, while the primary sinks for
groundwater within the model area are the pumping wells. In
order to develop the ground water system model, the
following boundary conditions must be defined:
Fig.3. Grid design study area.
A. Grid Design
The model domain was selected to cover 4294.75 km2 and
its consists of 116 rows, 180 columns and one layer with a
total of 20880 cells. The width of the cells along rows are
500 m in x-direction and along columns are 500 m in y-
direction as shown in Fig.3. The total number of cells
includes the active and inactive cells are 20880.However, the
numbers of active cells (i.e cells within the model domain)
are 17179.
B. Initial and Boundary Conditions
Depending on the regional groundwater flow pattern of
the confined aquifer and the field measurements of the
groundwater head in the wells of the new modern village of
Karbala city, the north and north-northeast boundary
conditions were chosen far enough for the well field effect to
be constant heads due to the existence of ALRazzaza Lake
north and Al Rshdiya River north-northeast, respectively, as
shown in fig.1. These constant heads ranged from 5 m in the
west to 60 m in south as shown in Fig.4. In addition, variable
head boundary prescribed the other sides of the modelled
area since it matches the flow directions (i.e. streamlines) .
Fig.4. Spatial Distribution of the average static
groundwater level in the study area (m.a.s.l).
V. INPUT PARAMETERS
Several input parameters were necessary to be provided
as initial values in order to use for simulation of steady and
unsteady state flow conditions. Hydraulic properties of the
aquifer systems were estimated using pumping tests analysis
and lithology of the aquifer system, as follows:
A. Aquifer Transmissivity
Initial values of aquifer transmissivity for confined
aquifer were evaluated from pumping test results of 10 wells
within the studied area. These values were used as initial
parameter values for the model. The values were altered later
during the calibration stage through trial and error. This has
been accomplished through transmissivity preparing contour

Artificial Recharge of Groundwater by Injection Wells (Case Study)
International Journal of Scientific Engineering and Technology Research
Volume.06, IssueNo.31, October-2017, Pages: 6193-6196
map for the values as shown in Fig.5. Where transmissivity
values ranged from (19-2090) m2/day.
Fig.5. Contour map of the transmissivity values of the
aquifer.
B. Storage Coefficient
The unsteady simulation requires initial estimates for the
storage coefficients of the aquifer. The average value of the
storage coefficient for confined aquifer was 1.2 ×10-4, fig.6
shows the contour map of storage coefficient.
Fig.6. Storage coefficient contour.
VI. GROUNDWATER RECHARGE SIMULATION
The calibrated model was applied to the confined aquifer
to predict the future changes in head in steady and unsteady
states for two scenarios under the actual water demand
situation.
A. Steady State Calibration
The calibration is an important part of any groundwater
modelling process. Moreover, in order to successfully
implement the groundwater model for any management
system, simulation of the aquifer behaviour must be
established (Anderson and Woessner, 1992) (3).
Calibration is a process where certain parameters of the
model such as recharge and hydraulic conductivity are
changed in a systematic fashion and the model is repeatedly
run until the computed solution matches field-observed
values within an acceptable level of accuracy. The model
was run for the steady state after the introduction of the
hydrological properties of the aquifer (Top elevation, bottom
elevation, Boundary condition, hydraulic conductivity, initial
head (fig.7 shows the computed and observed head in the
study area at steady state. The figure shows good
coincidence between competed and observed head.
Fig7. Computed and observed heads (a.s.l), (m).
B. Unsteady State Simulation
The output results of the steady state flow simulation
were used as initial inputs parameters for the unsteady state
flow simulation. Unsteady flow occurs during recharging,
therefore the dimensions of time and change in groundwater
storage must be incorporated. A system of 30 wells is
assumed to be installed each well is suggested to be
discharged at a constant rate of (1000 m3/d). The operation
periods of 67 and 365 days after artificial recharge
application were considered in the simulations as shown in
Figs.8 to 9 respectively. Fig.8 shows that the height of the
draw up in the groundwater table due to the recharging
process for 67 days ranges from 1 meter along the study area
and increases from 3 to 4 meters at the center to the northern
parts of the study area. Simulation results yielded several
contour maps for draw up of groundwater. Further
simulation was carried out to predict groundwater levels in
the wells within one year of recharge process. The
simulation output in Fig.9 indicated that an increase in water
levels for all wells especially those near the proposed
recharge areas are recorded. Maximum head rise reached to
20 m in the center of the area close to the recharge sites.

DR. IBTISAM R KARIM, ALI MAHDI ABD ALI
International Journal of Scientific Engineering and Technology Research
Volume.06, IssueNo.31, October-2017, Pages: 6193-6196
Fig.8. Height of groundwater levels after 67 days of
recharging.
Fig.9. Height of groundwater levels after one year of
recharging.
The model is there runnel through using pumping process
of 75 existing well to predict the ammonal of withdrawn
water from the aquifer. Fig.10 shows the amount of
drawdown in the groundwater tables as a result of the
pumping process for 67 days is found to be between 1 m on
the boundary of the study area and increasing to reach 20
meters in the center of the area after 365 days only, fig.11.
Fig.10. Drawdown in groundwater levels after 67 days of
pumping.
Fig.11. Drawdown in groundwater levels after 365 of
pumping. VII. CONCLUSION
The main conclusions of the theoretical work of this study
can be summarized as follows:
 The recharge process at the centre of study area caused
in draw up the groundwater level to 20 m in the centre
of the area after 360 days of wells operation.
 The maximum drawdown without recharge process was
measured to be 14.7 m after 360 days using unsteady
state simulation.
 Maximum annual amount of water that can be
artificially recharged in the confined aquifer is about
106 Million m3 when the recharge rate is about 1000
m3/day.
 The results of the simulation showed the importance of
the use of artificial recharge in improving water levels
and to avoid confined aquifer degradation in terms of
quantity.
VIII. REFERENCES
[1] Al-Basrawi, N.H., 1996: "Hydrogeology of Razzaza
Lake Iraq's western desert, Ph.D. Thesis. Baghdad
University, College of Science. Iraq.
[2] Al-Ghanimy 2013. "The hydrogeology of Dammam
aquifer in the west and south-west of the Kerbala city",
university of Karbala , college of science.
[3]Anderson, M.P. And Woessner, W.W., 1992,"Applied
groundwater modelling, simulation of flow and vertical
transport", Academic Press, Inc. San Diego, 246 P.