Sources of Ground Water In the Western Desert of Egypt

By: Prof Dr. M . Sabry Youssef (PhD)

The Eastern Desert as a Source of Oasis Water

The source of ground water in the Western Desert represents one of the most important unsolved hydrogeological problems in Egypt.

Different views have been suggested during the last century mostly lacking field observations measurements & material evidence, except John Ball who presented his work in 1927 accompanied by a map showing the contour lines of static water levels in the Western Desert

Previous authors   neglected probably unintentionally, depending on ground Water quality for tracing its source in spite the fact that soluble components in natural waters represent the only wetness on its Source from rainfall, to surface water, until final storage as ground water.

In addition, Ground Water in the Western Desert of Egypt represents a multi dimensional problem in which water quality vary in the three diminutions, as well as in age of aquifer source of its water.

Moreover, other discrepancies drawbacks in previous works is the belief of only one Source only one huge ground water reservoir.

A New Approach

More than fifty years ago, the Author realized the need to study Ground Water in Egypt on New Bases, the chemical analysis of dissolved salts, in ground water from different regions.

This necessitated :

1- Using Statistical methods to deal with the data collected.

2- Inventing New Techniques for Representation, classification and

    interpretation.

                                                   

                 Possible Sources for Oases Water

I- Local downward percolation:

1- From Local rainfall.

2- The River Nile.

In both cases, water salinity increases with depth. Whereas it is always found that Oases water decreases in salinity with depth.

Thus local downward percolation can be excluded as a source of Oases Water.

The Oases an Allochtone Ground water Region

II- lateral percolation of water from sources outside the Oasis:

1- Southern Sources:

Mainly Darb El Arbaein region, East oweinat region and the Sudan.

Water percolating from these regions will undoubtedly be higher in salinity than Oases water which allows to exclude these sources for Oases Water.

2- Western and Northern Sources:

These sources lack suitable environments for the formation of source water, its migration and storage.

a- Heavy rainfall .

b- Dense vegetation .

c- Basement rocks mainly granite.

d- Out crops of Nubian sandstone.

e- Static levels high enough to afford suitable gradient for the percolation of

    source water to the depths of the western Desert.

3- Eastern Sources:

All possible sources of water excluded except Eastern sources.

1- Source of Oases water lies to the East of the western Desert.

2- Environmentals and water quality are almost similar in Oases water

    and the White Nile.

3- Similar environments prevailed in the Eastern Desert during Pluvial

    periods. It is thus believed that Oases water was born on the Red Sea

    Mountains in the Eastern Desert of Egypt during Pluvial Periods

     thousands of years ago.

Sufficient evidence and confirmation will be given in the fallowing pages:

The Story of Oases Water

Quality of Source Water

Critical inspection of the chemical analyses of ground water from different oases locations and depths, there exists a limited number characterized by:

a- Almost similar chemical analyses.

b- Always the deepest

c- Nearest to geological structures especially faults.

These cases were nominated by the Author as the “Source of Oases water”

The Mighty Fresh Water Industry

Rain water is almost Distilled water, almost free of salts essential for animal and human life.

Thus Mighty water industry was created for the production of freshwater before the advent of man and for his existence and welfare.

Thus Freshwater was derived from rainwater and elements supplied by Igneous rocks in presence of carbon dioxide supplied by plants, through chemical weathering.     

A unique example is found in the formation of oases water in the Western Desert of Egypt from Past Rainfall on the Eastern Desert during Pluvial period.

The Fresh Water Source Equation

Na₂ O.Al₂ O₃        6 Sio₂         + Co₂          +  H₂O

Feldspar

Al₂ O₃. 2 Sio₂ . 2H₂O + Sio₂ + NH₂O + Na₂ Co₃                  

This equation represents a Mighty reaction which released metallic elements from silicate minerals at normal temperature in the atmosphere in presence of rainwater supplied by clouds high in the sky and dense vegetation and trees supplying the carbon dioxide essential for the reaction to produce Fresh water through chemical weathering.

This reaction occurred at normal conditions on top of high mountains.

It is miraculous that the same reaction in the laboratory requires fusing the silicate mineral in a platinium crucible in a muffle furnace at 1200  c

For many hours, as experienced by the Author in the Government Chemical Laboratories many years ago.

Favorable Environments in the Eastern Desert

1- During pluvial Periods, the Eastern Desert supplied the input

    components in the mighty reaction and equation, as follows:

     a-The liquid water (H₃O) as heavy rainfall from the sky.

     b-The carbon dioxide gal (CO₂) supplied by forests and dense

        vegetation on the earths surface.

     c-The solid metallic component mainly Na ,K ,Ca & Mg. supplied by

        igneous rocks from great depths in the earths crust to the ground

        surface:

               Na K from younger granites

               Mg from serpentines

               Ca from Basalt and older granites   

      Source water was thus formed on top of the Red Sea mountains.

2- Drainage basins collected the run - off and huge valleys water developed

3- Weathered basement rocks and over lying Nubian sandstone formations

    formed the outcrops which received the surface running source water

    and the birth of ground water in the Eastern Desert.

4- High altitudes of the Eastern Desert furnished enough static levels for

    ground water percolation to the heart of the western Desert, the Oases.

5- The relief of basement rocks below the western Desert interpreted from

     geophysical investigations.

6- The interpreted subsurface geological section across the South East to

     the North west covering the five Oases of kharga , Dakhla , Farafra,

     Baharia, Siwa and the Major fault (FF).

References

1- Sabry Youssef M.,(1957). Three new systems for the representation and

    classification of natural waters and their applications in Egypt:

I-      classification of ground water in Egypt.

II-   Relation between water quality and geological structure in kharga Oases.

III-                        New light on the origin of artesian water in the western desert in Egypt.

PhD thesis, Faculty of science, Cairo University.

2- Sabry Youssef M., (1998): Ground water in Arab nations. Text book

    published by the Academy of science and technology. Egypt. (In Arabic).