TERMS OF REFERENCE FOR CONSULTANCY
SERVICES
Modeling and Simulation of the Aquifers of the Jafer catchment
2012
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Contents
1. Background .................................................................................................. 4
1.1. INTRODUCTION ............................................................................................... 4
1.2. HYDROGEOLOGICAL FEATURES OF THE JAFER BASIN............................. 5
2. Scope of work ............................................................................................... 6
2.1. WORK PROGRAMME ...................................................................................... 6
2.2. SYNTHESIS AND FINAL REPORT ................................................................... 7
2.3. REPORTING ..................................................................................................... 7
3. Training ......................................................................................................... 7
4. Human resources ......................................................................................... 8
5. Work planning .............................................................................................. 8
6. Time schedule .............................................................................................. 8
7. Payments ...................................................................................................... 8
Modeling and Simulation of the Aquifers of the Jafer catchment
1.
1.1.
Background
Introduction
Jordan is facing a future of very limited water resources that is among the
lowest in the world on a per capita basis. Available water resources are
falling as a result of the population growth putting Jordan in the category
of having an absolute water shortage. Current use already exceeds the
available renewable supplies. The deficit is made up by the unsustainable
practice of overdrawing the Highland aquifers, resulting in lowered water
tables and deteriorating water quality. Projections differ on the amount of
future supply and demand for water, but they agree, without exception,
that there is a serious gap and that comfortable, realistic solutions to
close it are not apparent. With this alarming prospect, it is of the utmost
importance for Jordan to plan and manage the available water resources
with care, efficiency and resolve.
Water resources consist primarily of surface and groundwater resources,
with treated wastewater being increasingly reused for irrigation, mostly in
the Jordan Valley. Renewable water resources are including underground
water distributed amongst twelve groundwater basins and surface water
distributed amongst fifteen surface catchments. An additional resource is
estimated to be available from fossil aquifers (sandstone aquifer).
Brackish aquifers are not yet fully explored but it is expected to be
accessible for urban uses after desalination.
Based on the renewable groundwater divides configuration, twelve major
groundwater basins were defined in Jordan. Many studies and research
projects were done on many of the ground water basin which focused on
determining the quality and quantity of the shallow and deep aquifers.
Overexploitation of the shallow aquifers during the last two decades has
caused a general water-level decline and water quality degradation in the
Jafer basin.
The agricultural development in Jordan started in the early 1970s and
nowadays around 60% of the abstracted groundwater is being used for
irrigation. The increased agricultural land use brought about a
deterioration of groundwater qualities in many areas through the
application of fertilizers and pesticides. This is noticed chiefly by the
increasing salinities caused by irrigation return flows.
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The Jafer Basin is located in the south-central and southeastern part of
Jordan and borders the Sirhan Basin to the East, the Wadi Araba and
Red Sea Basins to the West and South, and the Wadi Mujib and Wadi
Hasa Basins to the north. The Basin encompasses a catchment's area of
12,364 km2 or about 15% of the area of Jordan.
Muhamadyyia well field (fodder project) has been developed in 2010 in
the north western area of the basin to sustain a growth of fodder to
support local sheep raising farmers. It is believed that the Jafer catchment
has being over-abstracted, and that new abstractions has induced a
stronger imbalance of the water budget. MWI is interested to investigate
the groundwater system dynamics, to understand the flow pattern and the
response of the groundwater system to stresses, and to improve the
sustainable management of Muhamadyyia well field.
Hydrogeological features of the Jafer Basin
Except for the highland areas along the Jordan Rift Valley to the west of
the Basin, generally low amounts of precipitation (< 50mm per year) are
received in the Basin. In the highland areas in the vicinity of Shaubak,
precipitation may reach up to 300 mm per year. The basin is sparsely
populated. The major urban area is Ma’an. The Jafer Basin essentially is
a depression within the overall topography of Jordan; surface water runoff
trends to accumulate in low-lying areas.
Surface Water in the Jafer Basin generally is limited to intermittent or
ephemeral streams and wadis, and runoff is usually associated with
intensive rainfall.
Groundwater within the catchment is exploited mainly from two main
aquifers :
Upper Creataceous Limestone Aquifer System: represented by B2/A7
Aquifer in Jafer Basin
Tertiary–Quaternary Shallow Aquifer Systems : represented by B4 Aquifer
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Groundwater is being used for three different sectors, Domestic supply,
Irrigation, and Industry, Irrigation consumes about 50% of abstracted
water, followed by Domestic with 30%, and 20% for Industry.
2. Scope of work
2.1 Work programme
As exposed in the previous chapters, the project will comprise four
successive phases:
Phase 1: Collection and assessment of the availability of hydrological
data in MWI, such as abstraction rates, water levels, rainfall and others.
Collection and assessment of the hydraulic parameters of the aquifers,
such as hydraulic conductivity values, transmissivity values and others.
Review of previous studies related to the basin and other modeling
approaches.
Phase 2: Building of a conceptual model, to demonstrate the geological
and hydrogeological setup and the boundary conditions applied for the
basin. The 3D model should be presented to MWI professionals for
further discussion.
Phase 3: Building of the numerical model; selecting a computer code
which is commonly used and familiar to MWI staff (preferably codes
based on MODFLOW code, e.g. GMS software). The code should be
capable of simulating steady and transient conditions for, homogeneous
or heterogeneous, and isotropic or anisotropic media. Particle tracking
must be available as a tool.
The design of the model grid size and the selection of stress periods and
time steps has to be discussed with MWI professionals. A calibrated and
verified model should be submitted with all input data and results digitally
with a licensed version of the software (Full Package). The modeling
should simulate stressed areas (well fields) in a finer grid size to better
demonstrate response of the aquifer system to stresses. Particle tracking
should be conducted to identify the capture zones for well field water
abstraction and the relative travel time. Recommendations on sustainable
abstraction rates for the well fields and the whole catchment for different
time steps should be submitted.
Phase 4: A training program will be provided to the MWI staff on how to
construct a groundwater flow model using the model which will be
developed for Jafer basin as an exercise material.
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2.2 Synthesis and final report

Global synthesis of the previous phases and reports.

Recommendations and conclusions.

Final report.
2.3 Reporting
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Two reports will be elaborated during the project:
At the end of Phases one and two one intermediary report will present the
work carried out during the different tasks of the phases and put forward
the main results, conclusions and recommendations.
The reports will be delivered to the MWI in three paper copies and one
CD.
A technical presentation will be organized in a meeting room of the
Ministry.
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At the end of the project, a final report will synthesize the four Phases
with their different tasks, findings, conclusions and recommendations.
The final report will be delivered to the MWI in ten hardcopies and ten
CDs containing all the reports, files, figures and maps created during the
project.
A technical presentation will be organized at the end of the project in a
meeting room of the Ministry of Water and Irrigation.
3. Training
Training of the Ministry professionals will be an important component of
the fourth phase of the project:
Furthermore, a one week training session will be dedicated on how to
build a groundwater flow model, manage scenarios, and prediction of the
impact of development carried out
4. Human resources
The staff will be composed of the following members, in the project:
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Senior Engineer or hydrogeologist and modeler, project leader.
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Senior geologists and modelers.
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Senior hydrologist.
5. Work planning
The project is planned for 90 days, according to the TOR.
6. Time schedule
1- Interim Report about the accomplished activities achieved results after
45 days of project commission.
2- Final draft report after 80 days of project commission.
3- Final report after 90 days of project commission.
7. Payments
Stage1- First payment: upon commissioning of the project 20% of the
total budget.
Stage 2- Second payment: upon the approval of the interim report, after
accomplishment of stage three, 30 % of the total budget.
Stage 3- Final payment: after approval of the final report, after the
submission, the rest or 50% of the total budget.
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