HYDROLOGY SYMPOSIUM

Proceedings of the

A N K A R A SYMPOSIUM

O N ARID Z O N E H Y D R O L O G Y

jointly organized

by the Government of Turkey

and Unesco

A R I D Z O N E P R O G R A M M E - I I

P R O C E E D I N G S O F T H E A N K A R A S Y M P O S I U M

O N A R I D Z O N E H Y D R O L O G Y

In the s a m e collection:

I.

III.

Directory a s Institutions Engaged in Arid

Zone

Research (published in 1953).

IV.

Reviews of Research on Problems of Utilization of Saline Water (in preparation).

V.

VI. Reviews

of Research an

Arid

Zone Plant Ecology (in preparation).

Reviews of Research on

Arid

Zone fIyd~010gy.

Proceedings af the Montpellier S y m p o s i u m on

Arid

Z o n e Plant Ecology (in preparation).

1953 by

Educational, Scientijîc and Cultural Organization 19, avenue Kléber, Paris-IGe

Printed

b p

Fortin, Nevers-Paris (France)

Printed in Frunce

NS.52.III.2A

C O N T E N T S

Preface

. . . . . . . . . . . . . . . . .

Speeches made at the opening ceremony

of

the symposium, 25

Apd

1952.

. .

<

. . . . . 7

. . . . .

11

I. The

physical a n d chemical properties of underground w u Research on the chemical properties of Turkey’s u ‘ 4 Physical and chemical properties of ground water

in

t countries,

by A.

Robaux. .

. . .

17

Omer

Caglar

. . . . . . . . . . . .

29

und-water resources,

by

Professor Kerim

II. The

statics a n d dynamics of underground water y S o m e recent studies

in

ground-water problems,

by

Dr.

F.

Dixey, C.M.G.,

O.B.E. . . . .

. 43

Statics and dynamics of water

in the

Syro-Lebanese limestone massifs,

by

Ibrahim

Ahd-el-Al

.

. .

60

Dynamics of ground water,

with

special reference to tube wells,

by

Dr. Nazir A h m a d .

. . . . 77

T h e measurement of ground-water flow,

by

Dr. Pierre Danel.

. . . . . . . . .

99

III. The

hydrological balance and the influence of utilization of undergrQuna-water u p o n it The hydrological balance and the influence of utilization of underground water upon it,

by R. D.

Dhir, Control of underground water resources to protect the hydrological balance and ensure intensive Reactions on the hydrological balance of the exploitation of underground-water resources,

by

Georges The application of hydrologic techniques to ground-water problems

in

California’s Central Valley S o m e aspects of precipitation and surface stream flow

in

ground-water recharge,

by

Professor R a y The importance of the phenomenon of capture

in

changes

in

the character of hydrological basins and

in

S o m e problems of hydrology and geology

in

artificial recharge of underground aquifers,

by Dr. W. I.S.E.. . . . . . . . . . . . . . . . . . .

.

.

111

organized utilization,

by

M o h a m e d

E l

Sayed Ayoub.

. . . . . . . .

115

Drouhin

. . . . . . . . . . . . . . . . .

125

Project,

by

Richard

L.

Boke and David

S.

Stoner.

. . . . . . . . . . .

134

K.

Linsley

. . . . . . . . . . . . . . . . . . . .

140

the

growth of desert and semi-desert areas,

by

Miss Rita Lopez de Llergo.

. . . . . .

151

C.LowdermiE

. . . . . . . . . . . . . . . . .

158

IV.

Prospection for underground water, and adaptation of drilling methods Outline of ground-water geology

in

arid regions,

by

Professor Leo Picard.

. . . .

165

Geophysical methods of locating ground water,

by L.

Cagniard

. . . . . . . . . 177

Boring and prospecting for ground water

in

arid zones,

by Dr. S.

Mazloum.

.

.

. . . .

184

T h e use of geology and applied geophysics

in

locating underground-water supplies,

by H. F.

Frommurze. 188 Hydrogeological research in central Anatolia and suggestions for different types of boring,

by

Mehmet Topkaya

. . . .

^,

. . . . . . . . . . . . .

192

Underground-water investigations

by

means of geophysical methods (particularly electrical)

in

central Anatolia,

by

Dr. Mehmet

Y.

Dizioglu.

. . . .

^,

.

^,

. .

,

. . . .

199

Prospection of ground water and adaptation of drilling methods to special conditions,

by Muhittin

Kulin

.

The exploration of underground water

by

means of geophysical and particularly electrical resistivity methods,

by

Professor Said-Ali Ankara.

. . . . . . . . . . . . .

Hydrogeological research

in

the basin of the Ergene,

by

Hamit

N.

Pamir.

. . . . . . V.

Relatìonship between the hydrology of underground water and other sciences

Ground water and h u m a n geography: ways of life in desert regions,

by

Professor Hassan Awad.

. .

of central Anatolia and its water-balance,

by

Professor

Hikmet

Birand.

. . .

: Ecological solutions of some hydrological and hydro-engineering problems,

by H.

Boyko.

. . .

Hydrogeology, meteorology, biogeography, archeology and sociolog Possibilities of improving the hydrological situation of Anatolia

by

Dr. Franz Heske.

. . . . . . . . . . . . . . . . .

Underground water as a factor

in

geological processes,

by E.

Sherbo

. . . . . .

United Nations Technical Assistance

in

the field of hydrological development

of

Afghanistan.

. .

216 221 224

235

239

247

255

259

262

265

P R E F A C E

RE

Arid

Zone Programme of Unesco, initiated in

1951,

is conducted under the guidance of an

T

^Advisory Committee on

Arid

Zone Research.

The

Committee chooses a special subject each year and concentrates major attention on this subject.

A

survey is conducted of research being undertaken in institutes in Member States; a panel of honorary consultants is set up; and reports are commissioned reviewing the present status of research in the subject.

These

activities lead up to a symposium

which

is organized in the following yeur jointly

by

Unesco and a Member State.

The

Committee’s object, when it establishes the pro- gramme for a symposium, is that participation in it should not be narrowly limited to specialists in the subject, but that interdisciplinary discussions should take place between experts in all the related sciences.

The

subject chosen for

1951

was

“Arid

Zone

H y -

drology, with special reference to underground water”, and the Committee expressed the hope that the symposium would be organized in conjunction with one of the countries in the

Middle

East.

The

Director- General of Unesco wrote to the governments of Member States in the

Middle

East, recommended

by

the Advisory Cornmittee, to ascertain

which

of them might be willing to join with Unesco in organizing the sympo- sium.

The Advisory

Committee, at its second session in September

1951,

learned with great satisfaction that the Government of

Turkey

had accepted the Director- General’s invitation, and that the symposium would be

held

in Ankara at the end of April

1952.

A

Turkish Organizing Committee was established under the chairmanship of Professor Hikmet Birand of the Department of Botany, Ankara University, and preparations began at Ankara, in Paris, and in Unesco’s

Science Co-operation

Osce

at Istanbul.

A

list of

the

persons who participated in the symposium will be found at the end of this preface.

The

Turkish Government invited those from the

Middle

East and the others were invited

by

Unesco.

The Turkish

Government

-

had invited the Director-General to convene the

third

session of the

Advisory

Committee at Ankara immediately before the symposium, thus giving participants in the session an opportunity of attending the symposium.

The

symposium was opened on the morning of 25 April

1952

at the Ziraat Fakultesi (Agricultural Faculty) of

the

University of Ankara by the chairman

?f

the

Turkish

Organizing Committee in the presence of the President of the Turkish Republic and the Ministers of Agriculture, Education, Health and Public Works.

The

sessions lasted until the evening of 29

April,

and were open to the public.

The

oficial languages of the symposium were English, French and Turkish, and simultaneous interpretation of papers read in one of these languages was given in the other two.

Eight reports reviewing published literature on arid zone hydrological research were prepared during

1952

and were available as background information for participants in the symposium.

These

reporzs were

published

by Unesco in

1952

under the title Reviews of Research on

Arid

Zone Hydrology.

After

the symposium, the

Turkish

Ministry of

Agri-

culture organized a study tour of the high plateau region of central Anatolia.

This

gave the participants an oppor- tunity of seeing at $rst hand the problems of the semi- arid region which w e r e referred ^to in a number of the Turkish communications at the symposium.

Unesco and its Advisory committee on

Arid

Zone Research wish to take this opportunity of expressing their gratitude to the Government of

Turkey,

the departments concerned and their oficers, to the

Turkish

National Commission for Unesco and to the

Turkish

Organizing Committee, for their efSorts in ensuring the success of this, the jïrst symposium to be organized under the

Arid

Zone Programme.

The

present publication of the proceedings of

the

sym- posium is being made

by

Unesco in English and French.

The

Turkish Ministry of

Public

Works is arranging for publication in

Turkish.

7

Preface

E X P E R T S W H O P R E S E N T E D PA PERS^ Dr. Franz Heske, Professor at the Universities of

A.

Robaux, Chief Geologist, H e a d of the Centre for

E.

Sherbon Hills, Professor of Geology at the University Hydrogeological Studies

in

Morocco.

Professor Kerim O m e r Caglar, Faculty of Agriculture, Dr.

S. W.

Tromp, United Nations Technical Assistance

Ankara University. Administration.

Dr.

F.

Dixey, C.M.G., O.B.E., Director of Colonial Geological Surveys, London.

Ibrahim Abd-el-Al, Director-General of Public Works, R E P R E S E N T A T I V E S OF O R G A N I Z A T I O N S Professor in the Higher School of Engineering, Beirut.

Dr. Nazir A h m a d , Head, Physics Department, Irriga- United Nations: Dr. Shen-Yi, Economic Commission tion Research Laboratories, Lahore, Pakistan. for Asia and the Far East.

Dr. Pierre Danel, Laboratoire Dauphinois d’Hydrau- Food and Agriculture Organization: Mr.

A.

de Vajda, lique, Neyrpic, Grenoble, France. F A 0 , R o m e . .

R. D.

Dhir, I.S.E., Director (Hydrology), Central ‘ International Labour Organisation: Professor Fadil Water and Power Commission, Government of Hakki Sur, Ankara University.

India, N e w Delhi. World Health Organization:

Mr. R. N.

Clark, Acting M o h a m e d

E l

Sayed Ayoub, formerly Inspector General, Director of the Division of Environmental Sanita- Nile Control, Egypt. tion;

Mr. J. O.

Buxell, Regional Adviser

in

Environ- Georges Drouhin, Director, Service de l’Hydraulique, mental Sanitation for the Eastern Mediterranean

Algeria. Region.

Richard

L.

Boke, Regional Director, Bureau of

Rda-

World Meteorological Organization: Professor R a y mation for California, Sacramento, California,

U.S.A. K.

Linsley, Stanford University, Cafifornia,

U.S.A.

David S.

Stoner, Regional Foreign Activities Coordi- International Association for Hydraulic Research:

nation, Bureau of Reclamation, Sacramento, Califor- Dr. Pierre Danel, Director of the Laboratohe Dauphi-

nia,

U.S.A.

nois d’Hydraulique, Neyrpic, Grenoble, France.

Professor R a y

K.

Linsley, Stanford University, Califor- International Geographical Union: Dr. Peveril Meigs,

nia,

U.S.A.

Route

4,

Box

91,

Vienna, Va.,

U.S.A.

Miss Rita Lopez de Llergo, Director of the Institute International Society of

Soil

Mechanics and

Founds-

of Geography, National Autonomous University tion Engineering:

Mr.

H a m d i Peynircioglu, Secretary,

of Mexico. Research Institution for

Soil

Mechanics of the

Dr.

W. C.

Lowdermilk, c/o Ministry of Agriculture and Technical University of Istadul.

Development, Jerusalem. International Union of Biological Sciences: Dr.

Hugo

Professor Leo Picard, Director, Geological Institute, Boyko, Chief Ecologist,

Ministry

of Agriculture and

Jerusalem. Development, Jerusalem.

L.

Cagniard, Professor of Applied Geophysics at the International Union of Geodesy

and

Geophysics:

Sorbonne University, Paris. Mr.

J.

Tixeront, Ingenieur en chef

du

Service de Dr.

s.

Mazloum, Director of Irrigation

and

Water Power l’Hydraulique, Directeur des Travaux Publics,

; s ’ T

in

Syria. Dr.

W. C.

Lowdermilk, c/o Ministry of Agriculture,

H. F.

Frommurze, Assistant Director, Geological Jerusalem.

Survey of South Africa. International Union for the Protection of Nature:

&hmet Topkaya, I k a d of the Hydrogeological and Professor

R.

Furon, H e a d of Unesco Technical Assis- International Union of Theoretical and Applied Mecha- nics: Professor Ratip Berker, Technical University,

Hamburg and Istanbul.

of Melbourne, Australia.

Geotechnical Department,

M.T.A.

Enstitusu,

h-

tance Mission in Turkey, Istanbul.

kara.

Dr. Mehmet

Y.

Dizioglu,

M.T.A.

Enstitusu, Ankara.

Muhittin

Kulin,

formely Director of Water Works, Istanbul.

Professor Said-Ali Ankara, Ankara University.

Hamit

N.

Pamir, Professor at the Geological Institute, Professor Hassan Awad, Ibrahim Pasha University, Professor Hikmet Birand, Ankara University.

H.

Boyko, Chief Ecologist, Ministry of Agriculture and Development, Israel.

R a y m o n d Furon, Hydrogeological Adviser to the Turkish Government, Head, Unesco Technical Assis- Ministry of Public Works, Ankara.

M E M B E R S O F T H E U N E S C O A D V I S O R Y C O M M I T T E E Istanbul, Turkey.

Cairo.

O N A R I D Z O N E R E S E A R C H (not reading papers) Dr.

B. T.

Dickson (Australia).

Dr. Roberto Llamas (Mexico).

Mr.

A.

Nizéry (alternate for Professor J. Pérès, France).

Dr.

H. G.

Thornton (United Kingdom).

tance Mission to Turkey. _{i In the ordçr} of their presentation,

Preface M E M B E R S O F T H E T U R K I S H O R G A N I Z I N G Dr. M e h m e t Topkaya.

C O M M I T T E E M r . Z e k i Torun.

Dr. H i k m e t Birand (President).

Mr.

A d e m Karaelmas.

Mr.

Z e y a K i r m a n .

Mr. I b r a h i m Sargut (Acting President).

Mr.

F u a t Senturk (Secretary).

Mr. Vahdi Y u r t m a n .

M r .

Emin

Hekimgil. U N E S C O S E C R E T A R I A T

Dr. F. J.

Malina, Representative of the Director-General.

Mr. W. E.

PurneIl, H e a d , Middle East Science

Co- Mr. J.

Swarbrick, D e p a r t m e n t of Natural Sciences.

operation Office.

9

S P E E C H E S M A D E AT T H E

O P E N I N G C E R E M O N Y O F T H E S Y M P O S I U M

25 APRIL 1 9 5 2

P R O F E S S O R H I K M E T B I R A N D

C h a i r m a n of the Turkish Organizing Committee

I

respectfully welcome the delegates, the representatives research laboratory for soil and

fluid

mechanics

in

the of the United Nations and its Specialized Agencies, . arid zone m a d e

by

the International Association of and the representatives of international non-govern- Theoretical and Applied Mechanics on 17 October 1947, mental scientific and technical organizations w h o have and the proposal of the delegation of

India in 1949

come to take part in the symposium on Hydrohgy of the regarding the foundation of an international institute Arid Zone

with

special reference to underground water. of research

in

the arid zone, were discussed, and it was The principal aim of Unesco is to achieve a world agreed that Unesco would study these proposals closely.

of happy people w h o love and respect one another. T h e

Gi-Iing

effect to this decision, Unesco convoked a commit- work undertaken to improve the arid zone is an impor- tee of specialists to meet

in

Paris during December tant step

in

this direction. Hitherto aridity has played 1949. Turkey took part

in

this committee

by

sending a destructive role in the fate of h u m a n beings, and has one scientist.

almost always beaten men in the immense zone under T h e committee

found

that it was too early to organize

its sway. an international institute of research on the a n d zone

If, with the help and collaboration of scientists of and suggested to Unesco the foundation of a research different nationalities united under the auspices of council on the subject.

Unesco, w e can

lay

down plans for aggression against This coumil, which had seven members proposed some, at least, of the weak flanks of aridity, and if,

by

different M e m b e r States of Unesco and appointed

by finding

methods to realize these plans, w e can even

by

the Director-General, held its 6rst meeting in Pai&

beat aridity, vast regions that are now useless and

in

November

1950

and prepared the programme of empty, but have the promise of great possibilities,

w i l l

activities which is still being carried out.

T o

assist in be conquered to the profit of humanity. achieving this programme an Ad-visory Committee o€

I

said “plans and methods” because aridity

is

not like seven members appointed

by

the DirecLor-General held a simple lock that can be opened

by

a n easily found its first meeting in Algiers in April 1951, its second master key, but is a scientific problem of m a n y phases meeting in Paris in September 1951 and its third meet- which is difficult to approach.

ing

at Ankara at the beginning of this week. This Even

if

the primaiy reason is the same, the results Advisory Committee has considered the problem from and symptoms

in

various regions m a y be different. different points of view and chose the subject of

“Arid

Furthermore, aridity is a relative rather than an abso- Zone Hydrology with Special Reference to Underground lute factor, and w e are not

in

possession of any scale like Water” for the year 1952.

a thermometer, to measure its intensity. Even the T h e Advisory Committee divided the arid zone into word aridity has a somewhat different meaning for the eight sections and asked specialists to prepare a report natural scientist and for the theoretical scientist. for each one. These reports are the basis of îhe discus- Aridity, except

in

some countries which are happy sions

during

the symposium. T h e programme for next enough not to k n o w it, is a factor c o m m o n to m a n y year covers arid zone plant ecology.

nations. It is indeed an international subject, and It is fortmate that the symposium on Hydiology of Unesco rightly considers it an important international the

Arid

Zone, with special reference to underground problem. Here is a short history of Unesco’s attempt to water, is being held

in

Ankara. O u r neighbours as

solve it. well as our own countrymen are familiar

with

the prob-

A t the general conference of Unesco

in

Beyrouth lem of aridity and these countries are well k n o w n

by

held

in 1949,

a proposal covering the foundation of a scientists w h o deal with the subject because they all

Opening ceremony of the symposium

have regions of natural and m a n - m a d e aridity. T h e latter are the results of alterations of the natural flora and of the disturbance of the climatological and edaphic biological eqiiilibrium, a disturbance reinforced

by

the trend of the climate towards aridity.

M a n - m a d e arid regions being as large as natural ones, they should constitute the first field offering success

in

the fight against aridity. T h e holding of this sympo- sium

in

Ankara is also very timely from another point of view. T h e first campaign zgainst aridity was star- ted

in

our country and its neighbourhood, the economic level of the area was improved

by

channels, d a m s and irrigation systems created

by

the old hydrologists.

Science and art thus then yielded their bountiful fruits.

For these reasons our country as well as our neigh.

bours m a y be a source of inspiration, especially to

hydro-

logists. O u r scientists and technicians of the last

35

years have been working on the problem of aridity, trying to solve it according to the requirements of the times, and they are,

I

a m sure, most pleased to meet their colleagues present here in Ankara on the occasion of this symposium and to collaborate with them.

Before concluding,

I

would like to thank the Director- General of Unesco whose assistance contributed so m u c h to the

holdling

of

the

symposium at Ankara, the

Minis-

try of Agriculture which organized the symposium

and

Dr. Malina

who

facilitated our work from Paris and

by his

efforts here afterwards.

T H E M I N I S T E R O F T H E M I N I S T E R O F

d

to welcome the delegates, the repre- sentatives of the United Nations and of the Specialized Agencies,

and

the members of international scientific organizations w h o are taking part

in

this international symposium on Hydrology of the Arid Zone with spe- cial reference to underground water.

T h e subject of the symposium is of great interest to the agriculture of our country. In Turkey, arid agriculture is widespread.

During

the excursion which willb e undertaken after the symposium

you wiU

have the opportunity of visiting one of our arid areas and of seeing the work done there.

W e are trying to solve this problem of aridity which

is

of such imnortance for our agriculture _{,. L} and economv.

Thus w e hope to profit from your scientific discussion and from the valuable ideh which

will be

brought out during this symposium and w e are very pleased indeed that it is being held at Ankara.

I

wish

you

complete success

in

your work and

a

very pleasant stay

in

our country.

M R . H I K M E T T U R A T

Representing the Ministry of

Public

works

D E L E G A T E S OF T H E S Y M P O S I U M ,

In the n a m e of the Ministry of Public Works

I

a m honoured to welcome the delegates of the symposium on Hydrology of the

Arid

Zone with special reference to underground water. This ministry is the agency which deals with the carrying out of projects of this nature

in

Turkey.

T h e climatic conditions of our country, dictated

by

its geographical formation, give a n arid character to several of its regions. In our country, which is under the influence of the world climatic cycle, the dry periods are experienced every

30

to

34

years. This effect has been painfully felt since

1928,

especially

in

the central

and southern Anatolian regions which have the charac- teristics of arid zones.

W e are aware of the fact that the present relatively wet period is ending and for the realization of some of our most difficult enterprises w e have but a short period of only

8 or 10

years. Although w e have completed the preliminary investigations and built the necessary projects

in

some of the regions near the seas,

in

the large central xegions which

do

not have surface waters,.and where geological formations are not suitable for the collecting of water

by

the formation of large reservoirs, w e are obliged to investigate the existence of under- ground waters and develop them wherever possible.

12

we

are only at the beginning of this very hard problem.

Today, w h e n this vital problem is

beginning

to be dealt with, it will

be

a source of great pleasure for us to have the opportunity to benefit from the experience and practical and theoretical howledge of scientiíic authorities.

I

wish to state here that only

with

the technical assist- ance of the United Nations and b y establishing a profit- able co-operation can w e accomplish this work.

In

this

limited

time

I

can merely state the import- ance and value of

the

hydrological and geological

sub-

jects

in

a very general way.

By

this short statement

I

can only m a k e it clear that although our determination to cope

with

unsuitable natural conditions is strong,

I

wish great success to the symposium.

M R . E M I N H E K I M G I L

Representing the Ministry of Education

MR. C H A I R M A N A N D M E M B E R S O F T H E S Y M P O S I U M ,

It

gives m e great pleasure to welcome all of y o u to the symposium on

Arid

Zone Hydrology on behalf of the Ministry of Education.

The

United Nations Educational, Scientific and

Cul-

tural Organization is investigating

a

very important

ñeld in

this symposium and one that is particularly per- tinent to this area. Therefore, Turkey is happy to have you here to work on this problem, and to receive advice from you.

W e believe that the only w a y to preserve peace and prosperity

in

the world is to bring scientists and educators together, and have them work on

the

problems which we mutually face, and follow up their recommendations.

Unesco’s aims can be achieved only

by

collaboration between Member States. The iUinistry of National Education has a deep interest

in

Unesco and its goals, and

is

therefore

very

pleased to contribute towards the

Organization’s success. In this connexion, the

Mïnia- try

of National Education was glad to m a k e arrange- ments and to set u p a committee for the symposium

with

the Ministry of Agriculture and the Turkish National Commission for Unesco.

Today w e begin the symposium after four days of intensive work

by the

Advisory Committee

on Arid

Zone Research.

One point which is

very

important to the succeas of this sort of scientific meeting is the distribution of publications. W e shall be very glad to see the results of this symposium published

in

Turkish as

w e l l

as

in

the working languages of Unesco.

I

thank all the participants

who

have come long dis- tances’to join this meeting. W e are ready to answer questions and to provide any other services.

Good luck

in

your work on the problems of hydro- logy of the arid zone. Thank you.

DR. H A S S A N A W A D

-

Chairman. of the

Third

Session of the Advisory Committee on

Arid

Z o n e Research

MR. PRESIDENT,

It is

a real honour for m e to speak

in

the n a m e of

m y

colleagues, the members of the Advisory Committee

on Arid

Zone Research on the occasion of this s y m - posium.

For the members of the committee the significance

of

the symposium

is indeed

great, because it

is

the first

of its

kind.

It fulfils our aspirations and embodies in a concrete form the committee’s work, the object of which

is

the development of arid zone research.

The committee has,

in

fact, from its establishment, accorded priority to arid zone

hydrology,

particularly the problem of underground water, because all h u m a n activity

in

the

arid

zone

is

conditioned

by

water.

Opening ceremony of the symposium

The

€act that your government,

Mi,.

President, agreed to organize

in

collaboration

with

Unesco a symposium of this

kind

is a great encouragement to our committee

in

the accomplishmcnt of its task.

We

are

deeply

grateful to the

Tm-kish

Government for its valuable assistance.

It

is only

right

that acknowledgement should

be

m a d e to the members of the Organizing Committee w h o have left nothing undone to ensure the success of the sym- posium. It is

indeed

a

triumph

to have gathered to-

gether so m a n y well-known specialists and scientists, and to have drawn

up

a programme covering SO completely the various aspectc of the problem.

Finally we are grateful to

the

Turkish Government for their hospitality and for having agreed to the hold- ing of

the

third session of our committee

in this

beau- tiful capital.

M y

colleagues and

I

are convinced that, thanks to

the

efforts of our Turkish friends, this session held at Ankara will mark an important stage

in

the work of our committee.

DR. F. J. M A L I N A

Representative of the Director-General of Unesco

M R . PRESIDENT, science and technology,

w i l l bring

this approach a step

It

is a

high

honour for the rep e

of

the Director- closer to realization.

General of Unesco to participate

in

the opening cere-

On

behalf of the Director-General

I wish

to express m o n y of the Unesco-Turkey Symposium on

Arid

Zone

his

great appreciation to you,

Mr.

President, and your Hydrology. This symposium is one of the most impor- government for making it possible for this symposium tant events of the Unesco

Arid

Zone Programme, and and the third session of the Advisory Committee to

he

is the first to be organized

by

Unesco and one of its held at Ankara.

I

wish deeply to thank the Turkish Member States under this programme. Organizing Committee, which under the presidency of Yesterday the third session of the Advisory Commit- Professor Birand was largely responsihle for prepara- tee on Arid Zone Research was concluded

in

this

build-

tions for the symposium.

The

authorities of

the Uni-

ing.

Dr.

A w a d , chairman of the session, has just versity of Ankara have

been

most generous

in

providing spoken to you. T h e success of the symposium willin a facilities for the meetings. Finally,

I

would

like

to large measure be due to the careful thought given to it

by

express

the

eneral’s thanks to the experts

who

the committee last year. The committee has repeatedly have, inm a s, corne from distant countries to stressed the importance of egrated m a k e their CO ons to

the

important and rapidly ex- scientific approach to the prob

ping

arid panding

field

of underground hydrology. T h e Director- land. T h e presence of experts ontinents General wishes the best s cess to the symposium

of

the world, w h o are speci elds of which is

beginning

today.

I

TI-IE P H Y S I C A L A N D C H E M I C A L P R O P E R T I E S

O F U N D E R G R O U N D W A T E R

P H Y S I C A L A N D C H E M I C A L P R O P E R T I E S

O F G R O U N D W A T E R IN T H E A R I D C Q U N T R I E S

bY

A. ROBAUX

Chief Geologist

Head of the Centre for Hydrogeological Studies in Morocco

The physical and chemical properties of ground water are studied

by

all hydrological services, which are trying to improve analytical methods and discover ways of

using

such water for irrigation purposes. Practical information, however, is but rarely available, for even where laboratories possess analytical statistics and m a k e discoveries which might be applicable elsewhere, they hardly ever publish their findings.

I

have therefore

been compelled to compile strength of correspondence

the present report on the

with

certain countries and

u

of experience obtained

in

the countries of North Africa;

and

I

hope that a detailed discussion

wiU

arise on the subjects dealt with

in

this paper, and lead to publica- tions on analytical technique, on the interpretation of results and, above all, on their practical application.

P H Y S I C A L P R O P E R T I E S O F G R O U N D W A T E R

In

general, the physical properties of ground water are the same

as

those of surface water.

VISCOSITY

Viscosity is dependent on temperature and, to a slight extent, on the salts

i n

solution.

The salt content of usable water never exceeds 3-4 gr.

per litre, and the temperature only rarely exceeds 25oC, so that one m a y consider the viscosity of water in arid countries to be the same as

in

temperate countries.

S U R F A C E PRESSURE

Similarly, surface pressure is practically speaking un- changed within the limits of temperature of natural water.

COLOUR, TASTE, SMELL

Since the water of arid zones is warmer and has a higher mineral content than the water of temperate countries,

it often has a strong taste, which becomes more unplea- sant as the temperature and mineral content rise. It is mainly the

Mg

content that causes this disagreeable taste.

Neither smell nor colour are changed.

T E M P E R A T U R E

T h e temperature alone undergoes m a n y substantial chan- ges, and it is worth describing their cause and effect.

With

the exception of Monod and Collin in the United States, and D a y

and

Allen, Oddone, Adams, Passerini and Schoeller for Tunisia, w h o have on occasion mentioned some specific points, no author would appear to have taken the trouble systematically to analyse the tempe- rature of water

in

the arid countries.

I

shall therefore summarize our theoretical knowledge, as well as our knowledge of the temperate countries which form the subject of a remarkable study

by

Professor Schocller of Bordeaux University, and

I

shall seek to apply that knowledge to water

in

the arid countries, while adding certain personal observations of

my

own.

T h e temperature of ground water is directly and almost

17

ïhe

exclusively related to the temperature of the ground itself, except of course

in

the case of juvenile water resulting from deep-seated chemical combinations.

It therefore depends on the average temperature in the region

witLin

the zone of variations above the iso- therm, that is to say: on the action of the climate and the sun; on the action of the geothermic degree below the isotherm; on physio-chemical action (inhibition of colloids, oxidation of carbonaceous matter, exothermic alteration of minerals, loss of pressure

in

a water-table, variations

in

pressure) which is of little importance

and w i l l

not be discussed

in

detail.

action of external temperature, since less deep-lying water-used

by

the inhabitants because of its greater accessibility-is, and will long remain, of overriding importance.

In arid countries, the average temperature of the air is higher than

in

temperate zones, and the temperature of underground water in consequently higher too. This is a fact which has been observed everywhere.

Since, however, the temperature of the soil varies between night and day, and also from one season to another, there

is

a daily and an annual variation in the temperature of the soil and therefore

in

the temperature of the water .which flows through it.

M u c h of the water in arid cou

W e shall thereiore study this

in full.

D A I L Y VARIATIONS

T h e velocity of propagation is

where

K

is the thermic co-efficient, generally equal to

0.004 C.G.S.

for ordinary soil, 0.01 for limestone and

0.02

for granite (according to Schocller); and where 7

is the period of duration

(24

hours or 3 phenomenon.

T h e depth of the daily neutral zone naturally depends on the extent of the variations

in

temperature at the soil surface and on its speed of propagation.

According to Schoeller, this depth, depending

on

the nature of the ground, is as shown

in

Table 1.

TABLE 1.

Variation up to a daily Limestone Granite Ordinary soil Variation in temperature neutral zone

at ground level

cm. cm. cm.

100

. . . . . . .

115 162 72.6

Z O O

. . . . . .

126 178 79.8

300

. . . . . .

133 188 84.1

500

. . . . . .

141 200 89.6

Thus

even the most marked variations in temperature in the arid countries take effect only at depths of 90 cia., 150, or

200

cm., depending on the thermic conducti-

bility

of the soil.

A N N U A L V A R I A T I O N S

Theoretically, the velocity of propagation of annual waves is one-nineteenth that of daily waves. W h e r e the co-efficient

K

is the same as before,

if

the velocity of daily propagation is,

say,

89.5 cm., the annual velo- city

will

be 4.7 cm. per day.

Consequently the annual neuti.al zone, or the neutral zone in the strict sense of the term, is still an isothermic zone. It is of course deeper, and descends to the depths (according to Schoellcr) shown

in

Table 2.

TABLE 2.

Yariazion up to an annual Limestone Granite Ordinary soil

m. m. m.

Variation in temperature neutral zone at ground level

. . . .

24 34 15.2

. . . .

25.4, 35.9 16.1

500

. . . . . .

26.9 38.2 17.1

600 . . . 27.6 39 17.4

T h e neutral zone

in

arid countries is therefore of the order of: 17-18 m. for ord

y

terrains-scrce, alluvial deposits, terrigenous dep , sand and gravel; 28 m.

for limestone, sandstone, calcareous marl, etc.; 39 m.

for granite,

and

for eruptive rock which is a very good conductor of heat.

In conclusion, the temperature of water which follows the temperature of the soil is itself closely related to the rature of the air, and

w i l l

be higher, the It attains: 170 to 220

in

semi-arid zones; 220 to

250 in

more arid zones; 250 to 300

in

arid, desert or tropical zones.

Daily changes

in

temperature affect the temperature of ground water to a depth of

1.50

or 2 m.

Annual

variations (relating to the neutral zone

in

which the soil temperature equals the average temperature of the air) affect ground water to a depth of

15-20

m. and,

in

eruptive rock, to a depth of as m u c h as 30 m.

Between these two zones w e have a heterogeneous annual zone,

in

which one often finds stretches of surface water, such as are utilized in arid countries.

The

action of the geothermic degree is felt below the isotherm, that is to say, in the case of deep underground water-tables (ascending or circulating at great depth).

There are m a n y examples of this

in

arid countries, and there

will

be an increasing tendency

in

the future to make use of these underground waters.

W e know that the geothermic degree is in the nature of 33, but it is

in

fact very variable, depending on the

o w a r m regions.

Physical and chemical properties of ground water in the arid countries terrain. T h e water conveyed through the various ternperaturc of the rain or the infiltrating water have strata

will

be aEected

by

the action of heat from a no influence. T h e temperature of the water

w i l l

be fairly

depth

of

30-40

m., i.e. below the neutral zone, and, homogeneous. A t the exits, it

w i l l

he the same as the except

in

particular cases, its temperature

w i l l he

related temperat-ie of the water-table itself, and vegetation to the heat engendered in the lower levels of the earth's (almost non-existent

in

arid countries)

w i l l

have no effect.

crust, rather than to the outside air.

Thus water which passes through low-lying strata T A B L E 3. Water of a phreatic water-table in the pre-

w i l l

have a temperature related to this geothermic Sahara

degree, and in the case of ground water in arid countries Temperature of underground the following applies: (a) the country's aridity no longer

appears to influence the temperature of the water, since ^water

everything happens below the superficial zone influenced Maxi- Mini- Aue- Muxi- Mini-

by

climate. Deep-lying water

in

arid countries m a y m u m mum rage m u m m u m therefore be dealt with in the same w a y as such water

in temperate countries. This applies to water which Erfoud

flows underground at considerable depth before re- Essani

appearing as artesian or rising water;

(b)

deep-seated Southern plaini 300 14.20 22.10 23.20 160-170 juvenile water usually has only a very weak flow and is 4 BY comparison with Beni-Ablies (September 1950 to Aupst 1951).

therefore practically speaking of no value in connexion

with

the use of water; (C) whatever its temperature W e m a y therefore derive the following law: In arid when it reaches the heterogeneous zone, water which countries, water

which does

not

lie very

deep

and

has risen from a great depth aPPrOaches the temperature emerges from ground that is

only

slightly permeable has of

face

Water OJ$' very Slowly (for instance, deep a temperature 10-30 higher than the average tempera- water rising to join a phreatic water-table), SO that tures

research might wellreveal zones

in

which warmer water emerges from great depth into a water-table at a differ-

enttemperature;

(d)

inthe open air, on the other hand, T E M P E R A T U R E OF S U R F A C E W A T E R IN M O R E heat is lost very quickly and the water very soon

returns to its normal temperature, SO that it

may

often not be realized that it was w a r m on emerging from the earth.

Average air temperature

Ksar es Souk 27.4." 11.90 19.70 21.5" 160 28.60 13.40 210 22.2O 160 29.6' 13.60 21.6' 23" 16'-17"

place.

P E R M E A B L E S T R A T A

On

the other hand, water which flows at no great depth, but always downwards, through highly permeable strata

(porous cracks) will behave very differently.

The variations

in

the temperature of the water are very great on account of: (a) the high temperature of the water

in

the infiltration area;

(h) the

small loss of heat in the channels through which the water flows, so that it maintains its infiltration 'temperature for a long time and varies with that temperature; (c) the speed of the flow, which is rapid and gives no opportanity for exchanges;

(d)

the great variations

in

the volume of water in such springs

(in

arid countries), which are often

dry

in summer,

wiless

a privileged geological situation allows a reserve to be built up which can maintain the flow at the points of reiemergence.

The longer the water flows underground, however, the more homogeneous

w i l l

b e its temperature. T h e gaps between the temperature

of

the soil and of the water

may

then vary between

+

20 and -70 or

-

80.

This

shows that, in arid regions as elsewhere, the tem- perature of water is directly related:

1.

T o the average temperature of the air, that is to say, to the solar flux,

in

the case of water flowing in the heterothermic zone at no great depth.

2.

To

the $ow of warmth emanating from the centre of the eurth

in

the case of underground water circulating below the neutral zone and therefore a m o n g deeper geological layers.

Thus geological condttions have

a

very great effect on the temperature of ground water near the surface, and the temperature of the infiltrating water

will

differ from that of the water which feeds the water-table, according to whether it flows through more or through less permeable strata.

T E M P E R A T U R E O F S U R F A C E W A T E R IN L E S S P E R M E A B L E S T R A T A

The water of water-tables

in

terrain which is

only

slightly permeable (permeable only through interstices), such as alluvial phreatic water-tables, will therefore have the temperature of the neutral zone it normally OCCU-

pies. Thermic conductivity is high and the rate of drainage slow, while the height

of

the place and the

Howeyer, at these levels at

any

rate (170-280) tempera- ture has no influence on the vegetation and crops of these countries. Nevertheless, both germination and growth of irrigated plants are undoubtedly activated

by

warmer water.

Moreover., the temperature

wiU

facztate evaporation and have a considerable effect on the

high

mineral content of water

in

the arid countries.

19

T h and chernicul properties of underground water

C H E M I C A L P R O P E R T I E S O F G R O U N D W A T E R

G E N E R A L

T h e general situation is as follows:

Water

in

the subsoil o€ arid countries is far richer

in

mineral salts than water of the same strata

in

temperate countries. T h e chloride content is particularly high,

and

the chemical action of the soil

on

the water is quite different.

In

order of solubility; the following are the main salts:

Negative ions: CI-,

SO,=, HC0,-, CO,=, SiO,=, NO,-;

Positive ions: Na+,

K+,

Ca++,

Mg++, Fe++.

Normal analytical methods also reveal other, rarer elements (fluorine, boron). Colorimetric, conductivity and polarographic methods are being increasingly stu- died and used on account of their advantages (speeii and economy). T o study irrigation and even consumption waters in arid countries, it is not necessary to have

highly

accurate analyses. Thus all authors agree in considering that a determination to within about

5

per cent is quite sufficient, and that it is preferable to m a k e a large number of such analyse a n to seek greater precision

in

a few.

Basing themselves

on

the results of analysis, a number of authors-Stabler, Palmer, Frey, etc.-have tried to reconstitute the salts actually present

in

the water.’

For the purpose of utilizing the water, however, the only useful methods are those which permit a compari- son between different types of water. Here, there appear to be t w o processes which are particularly appropriate: presentation on a logarithmic diagram, as used

in

North Africa; presentation as concentration of

NaCl in

relation to all the other salts, as used

by

the Colorado Bureau of Reclamation, especially

in

order to discover the irrigation value of a given type of water.

T h e presence of the salts thus revealed: NaCl;

KCl;

CaSO,;

MgSO,; Na,SO,;

Ca(HCO,),;

Mg(HCO,),

results from the solution of rocks.

T h e action of carbonic gas emanating from the weathered layers of the upper parts of the soil plays

an

important part in these dissolving processes. B u t recent studies have suggested a n e w idea. T h e

CO,

contant of the upper layers of the soil is low (the

CO,

content is only from

0.001

to

0.01,

although that is still

30

to

40

times the

CO,

content of air), and conse- quently bicarbonates resulting from the action of

CO,

on the terrain cannot be very abundant

in

water at atmospheric pressure.

On

the other hand, since the slow B o w of water through the soil and the effect of pressure increase the

CO,

content, the bicarbonate content can also rise. It is important to emphasize that, under such conditions, the salts willto all intents and purposes be of the same degree of concentration inthe water of arid countries as in the water of tem- perate countries. There is a slight increase in salt content

in

the semi-arid zones, but, on the other hand,

it is distinctly lower

in

the waters of the Sahara.

In

his study on the mineralization of water as related

LO the average temperature of climates, Schoeller demonstrates this very clearly.

MINERALIZATION

Given the above,

and

except for the special case of active

CO,

(that is, of the bicarbonates it forms), the mineraIization of water depends

in

all countries on the nature of the terrain through which it flows.

In

the arid countries however such mineralization is exaggerated, wherever the terrain permits, owing either to concentration

by

evaporation or to the salts

i n

the ground being dissolved, or to both together.

W e

w i l l

therefore study the effect of different types of terrain on the mineral content of water.

W A T E R IN L I M E S T O N E

It is well

known

that water can circulate

in

limestone only through fissures or interstices

(in

compact or fine-grained Iimestone), and sometimes through the pores (in porous or coarse conchìtic limestone). T h e most important channel is formed

by

the fissures, and soluble elements can therefore be dissolved only on the surface of such fissures. But soluble elements -chlorides and sulphates-are rare

and

are

bound

up

with the mass of the limestone,

owing

either to the rock’s low content

in

soluble ele- ments, or to the fact that those elements have only a slight area of surface contact, limestone water is generally low

in

mineral content, even in the arid coun- tries. Such water is therefore excellent both for irriga- tion and consumption (dry residue at 1800 around

500

to

1000 mg. /I.; CI

around

50

to

150 mg. /I.),

A t the same time,

I

would recall that the dissolution of limestone (carbonate) depends exclusively

on

the

CO,

content of the water

and

that,

in

general, the water obtains its

CO,

content from the surface layers which are rich

in

organic matter, and hence

in CO,.

A s soon as the water is subject to pressure at grcat depth, the

CO,

content increases and then to its maxi- m u m capacity it dissolves the limestone- it encounters.

Consequently, on reaching the open

in

the form of a spring under normal pressure, that water immediately precipitates its carbonates as powerful “travertines”.

Unless subject to pressure, water is therefore almost incapable of dissolving limestone.

In

the arid countries, however, there is no, or almost no, vegetal covering. T h e

CO,

content of the water is therefore low and it is consequently a poor solvent.

Another characteristic of limestone is that it is

Physical and chemical properties of ground water in the arid countries generally very permeable at the surface, causing the

water it receives to disappear rapidly into the depths, so that it has no time to evaporate.

These two facts no doubt explain the anomaly whereby limestone water in the Sahara proper is less rich in carbonates than it is

in

the semi-arid border country (Algeria and Tunisia).

W A T E R I N C L A Y A N D M A R L

Neither clay nor marl is very permeable. Water there- fore flows through t h e m slowly and never descends deep enough to escape the action of evaporation and capillarity. There are a number of soluble elements, and such ground therefore always gves water of very poor quality

(dry

residue varying between 2,000 and

4,000 mg. /I.; C1

around

1,000 mg. /I.).

Base exchanges also occur as a result of lengthy contact between the water

and

the clay or marl.

I

should like to point out

in

passing that clay and marl produce mediocre water

in

temperate countries too, although the water there is less bad than

in

arid countries, because there is less concentration

by

evapora- tion, and because the ground is less rich in soluble salts.

Finally, at the time they were deposited, these rocks were able to absorb

up

to

50

per cent of their own volume of water from the medium of sedimentation, i.e. the sea (it is remarkable in this respect that water

in

lacustrine marl-fresh water-has a far lower mineral content than the water of marl sedimented from a marine medium). Moreover, especially

in

arid countries, there has been no opportunity

in

more recent times for the salt to be leached.

W A T E R I N S A N D S T O N E A N D S A N D

As in

the case of marl

and

clay, water

in

sandstone and sand flows through a very porous medium, but usually slowly, so that the water coming from such strata usually has a higher mineral content than water from limestone, although less than that of marl.

T h e bicarbonate content is the same as before, and always for the same reasons. However, it is well to remember that, according to Schoeller, combined

CO,

increases in the semi-arid regions and diminishes

in

the Sahara.

N o n e the less, siliceous limestone is of course poorer

in CO, in

combination, even

in

the Sahara.

Like alluvial deposits or detrital formations, sand and sandstone in arid countries are subject to intense evaporation and capillarity, so that there is a consider- able increase

in

the

CI

and

SO,

content

in

dry countries.

T h e dry residue varies between

1,000

and

2,000

mg. /i., while chlorides average less than

500 mg./l.

WATER IN ALLUVI’AL SOIL

By

its origin, alluvial soil is composed of a number of different elements-sand, pebbles, river clay, etc.- but it is distinguished

by

the fact that it has heen transported and stirred

up,

and then had water passing through it for long periods. Such ground has therefore lost whatever soluble elements it m a y have originally contained. Apart from the harder materials, however, alluvial soil contains geological horizons of clay, silt and sandy clay, etc.,

in

which water can circulate

only

very slowly. Moreover, alluvial soil contains water-tables which are nearer the surface of the soil, so that, in the arid countries, there is intense evapora- tion, while capillary migration is very active, a n d even today the clay zones continue to dissolve.

All

in all, the quality of alluvial water in the

zrid

countries is very variable. Moreover,

in

the course of geological time, such soil has often been the centre of physio-chemical reactions which have consolidated it into a thick crust, often several dozen metres thick.

It must be remembered that there m a y be under- ground drainage from aquiferous strata which dis- charge the varied types of water they bear into the alluvial soil.

W A T E R I N S H A L E A N D W E A T H E R E D ERUPTIVE R O C E S

In

the arid countries, the type of water found

in

shale and weathered eruptive rocks is one of the most remark- able of those under consideration.

Thus whereas,

in

temperate countries, such formations contain very fresh water with little C a content, little

Mg,

little

CO,,

almost no C1, and only traces of

SO,,

the composition of that water is quite different

in

arid coun- tries, where it has a high

CI

and

SO,

content, consider- able quantities of

CO,

and Ca, and considerably more

Mg

than is usual. This

high

mineral content is found even

in

zones of high rainfall

(500-600

mm.) and in fairly deep-lying water-tables

(25-30

m.). T h e

only

can- dition is that the climate should be arid, i.e. that there should

be

a sufficiently long clry period each year between the rainy periods.

Formations of this type are only slightly permeable, and the water passes through

in

small quantities. T h e proportion of clay is

high,

the rate of B o w slow, dissolu- tion active, and the effects of capillarity intense.

T h e

kind

of water found

in

shale and weathered rocks is of one the worst in arid and semi-arid countries (2,000- 3,000

mg. /i.

of

dry

residue at 1800, 1,200

mg. /I.

of

Ci).

21