Date of Award

6-2014

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Environmental Science

First Advisor

Dr Ibrahim Kocabas

Second Advisor

Dr Waleed Khalil AI-Zubari

Third Advisor

Dr. Ahmed EI Mahmoudi

Abstract

AI Wagan area lies to the south of AI Ain City of the eastern region of Abu Dhabi Emirate

along the Sultanate of Oman-United Arab Emirates borders. AI Wagan area is important

for agriculture in the eastern region of Abu Dhabi. Ground water is the primary source of

irTigation in the area. The main source of recharge to the ground-water-flow system of the

entire eastern region of Abu Dhabi Emirate is rainfall on the Oman Mountains. Ground

water flows in an east-west direction because most of the recharge at higher elevations is or

near the Oman Mountains.

The ground-water-flow system of AI Wagan area consists of the upper, unconfined,

aquifer, the lower, confined, aquifer, and the intervening confining layer. The upper aquifer

refers to the saturated part of most the unconsolidated deposits of Quaternary age. Below

the Quaternary deposits, is a clay layer acting as a confining layer separating the upper

aquifer from the underlying lower aquifer. The conglomerate layer of the Post Fars

Formation primly comprises the lower aquifer. Water within the upper aquifer is

generally more mineralized than water in the lower aquifer.

The purpose of this study is to present:

1. A geohydrology description of the lower aquifer and the upper aquifer in the study

area,

2. An assessment of the changes of quality of the brackish ground water that might

result from large and prolonged withdrawals in the area, and

3. A description of the simulation of flow in the ground-water system.

Annual well withdrawals from the two aquifers were tabulated from records of the

Agriculture and Forestry Departments of AI Ai n and the Ground-Water Research Program

monitoring wells. The potentiometric surface of the lower aquifer is declining because of

large withdrawals for irrigation .

Geochemical analyses support the conclusion that the salinity of brackish ground water of

the lower aquifer in AI Wagan area increased with percentage ranged from 2 % to 74 %

from 1996 to 1998.

A three-dimensional, three-layer ground-water-flow model was constructed to help

understand the ground-water-flow system. Model results indicate vertical flow occurs

between the three model layers; possibly explaining the observed increased salinity of the

lower aquifer.

The use of the flow model as a predictive tool showed that if the current pumping rates of

the wells will continue in the future, this might lead to a complete aquifer depletion of the

upper aquifer at the north of the study area.

As a result of this study the following recommendations can be made in order to avoid

more depletion of the aquifer and deterioration of the water quality:

1. Minimize aquifer depletion, by reduction and of pumping rates and number of wells

in each farm.

2. Regulate ground-water use.

3. Enhancement of the observation well network.

4. Better well constructions.

Share

COinS