INTERNATIONAL HYDROLOGY SERIESWorld Water Resources at the Beginningof the Twenty-First Century

Edited by

I.A. ShiklomanovState Hydrological Institute, Russian Federation

andJohn C. Rodda
Past President, International Association of Hydrological Sciences,Centre for Ecology and Hydrology, Wallingford, Oxon

PUBLISHED BY THE PRESS SYNDICATE OF THE UNIVERSITY OF CAMBRIDGEThe Pitt Building, Trumpington Street, Cambridge, United Kingdom
CAMBRIDGE UNIVERSITY PRESSThe Edinburgh Building, Cambridge CB2 2RU, UK
40 West 20th Street, New York, NY 10011-4211, USA
477 Williamstown Road, Port Melbourne, VIC 3207, Australia
Ruiz de Alarcón 13, 28014 Madrid, Spain
Dock House, The Waterfront, Cape Town 8001, South Africa
http://www.cambridge.org

C UNESCO 2003

This book is in copyright. Subject to statutory exception
and to the provisions of relevant collective licensing agreements,
no reproduction of any part may take place without
the written permission of Cambridge University Press.
First published 2003
Printed in the United Kingdom at the University Press, Cambridge
Typeface Times 9.5/13 pt

System LATEX 2ε [TB]

A catalogue record for this book is available from the British Library
Library of Congress Cataloguing in Publication data
World water resources at the beginning of the 21st century / scientific leader and editor,
I.A. Shiklomanov, John C. Rodda.
p. cm. – (International hydrology series)
Includes bibliographical references and index.
ISBN 0 521 82085 5
1. Water balance (Hydrology) 2. Water use. 3. Water consumption. I. Shiklomanov, I. A.
II. Rodda, J. C. III. Series.
GB661.2 .W67 2003
553.7 09 05 – dc21 2002031201
ISBN 0 521 82085 5 hardbackContents

Introduction
I.A. Shiklomanov

1
1.1
1.1.1
1.1.2
1.1.3
1.2
1.2.1
1.2.2
1.2.3

The Earth and its physical features
V.I. Babkin
Physical geography
V.I. Babkin and V.S. Vuglinsky
The area of the Earth’s surface
The World Ocean
Continents and islands
The hydrosphere
V.I. Babkin and R.K. Klige
The origins of water on the Earth
The contemporary hydrosphere
Global water exchange in the hydrosphere – the hydrological cycle

2

page xi

1
1
1
1
1
10
10
13
17

Water resources assessment
V.I. Babkin
2.1
Assessment methods
2.2
River basins and continents
2.3
Natural regions, countries and continents
2.4
The distribution of water resources within the year
2.5
Methods for studying long-term variations in water resources
2.5.1 Methods for assessing stationarity and trends
2.5.2 An assessment of cyclic variations

19
20
22
22
23
23
25

3

27

3.1
3.2
3.2.1
3.2.2
3.2.3
3.2.4
3.3

Methods for assessing and forecasting global water use and water availability
I.A. Shiklomanov and N.V. Penkova
The human impact on water resources
Water use
Municipal water use
Water use by industry and for power production
Water use by agriculture
The role of reservoirs as users of fresh water
Methods for assessing and forecasting water use and availability

19

27
30
30
31
33
36
37

v

vi
4
4.1
4.2
4.2.1
4.2.2
4.2.3
4.2.4
4.3
4.3.1
4.3.2
4.3.3
4.4
4.5
4.5.1
4.5.2
4.5.3
4.6
4.6.1
4.6.2
4.6.3
4.7
5
5.1
5.2
5.2.1
5.2.2
5.3
5.4
5.5
5.5.1
5.5.2
5.5.3
5.5.4
5.6
5.6.1
5.6.2
5.6.3
5.7
5.7.1
5.7.2
5.7.3

CONTENTS

Water resources, water use and water availability in Europe
I.P. Zaretskaya
Introduction
Physical conditions
ReliefSoils and vegetation
ClimateHydrology
Socio-economic conditions and the use of water resources
Population
Economic development
Use of water resources and water use assessment
Hydrological data
Distribution of water resources in time and space
Initial data and methodology
Water resources of rivers and basins draining to the different seas and oceans
The water resources of certain countries and regions
Changes in water use and water availability
Initial data and preconditions
Changes in water use
Water availability for the regions and for individual countries
Conclusions
Water resources, water use and water availability in Asia
Introduction
V.P. Yunitsyna
Physical conditions
V.P. Yunitsyna
Relief, climate and vegetation
Hydrology
Socio-economic conditions and the use of water resources
N.V. Penkova
Hydrological data
V.P. Yunitsyna
Distribution of water resources in time and space
V.P. Yunitsyna and T.G. Markelova
Data and methodology
The water resources of natural regions and individual countries
The water resources of major rivers and the inflow to the ocean
The distribution of runoff within the year
Changes in water use and water availabilty
N.V. Penkova and I.A. Shiklomanov
Data and preconditions
Changes and trends in the use of water
Regional and national patterns of the availability of water
The problems of the Aral Sea Basin
K.V. Tsytsenko
The water resources of the Aral Sea Basin
Changes and trends in the use of water
Changes in the level of the Aral Sea and in the river flow regime

45
45
46
46
47
48
49
51
51
51
54
60
64
64
67
75
79
79
84
89
90
94
94
95
95
98
104
112
114
114
115
123
128
131
131
135
139
145
148
149
150

CONTENTS

vii

5.7.4 The ecological consequences of the development of the Aral Sea Basin
5.7.5 Ways and means of addressing the problem
5.8
Conclusions
V.P. Yunitsyna

153
153
156

6
6.1

157
157

6.2
6.2.1
6.2.2
6.2.3
6.3
6.4
6.5
6.5.1
6.5.2
6.5.3
6.5.4
6.6
6.6.1
6.6.2
6.6.3
6.7
6.7.1
6.7.2
6.8

7
7.1
7.2
7.2.1
7.2.2
7.2.3
7.3
7.3.1
7.3.2
7.3.3
7.3.4
7.4
7.5

Water resources, water use and water availability in Africa
Introduction
V.I. Babkin and E.L. Skoryatina
Physical conditions
V.I. Babkin and E.L. Skoryatina
ReliefClimate and vegetation
The river network
Socio-economic conditions and the use of water resources
N.V. Penkova
Hydrological data
V.I. Babkin and E.L. Skoryatina
Distribution of water resources in time and space
V.I. Babkin, E.L. Skoryatina and T.G. Markelova
Data and methodology
Water resources of natural regions and individual countries
Major rivers and flows to the oceans
The distribution of runoff within the year
Changes in water use and water availability
N.V. Penkova and I.A. Shiklomanov
Data
Changes and trends in water use
Water availability by region and country
Problems of water management at the continental scale
J.A. Balonishnikova
A brief review of the problem
The Aswan High Dam and Lake – the hydroecological and social consequences
Conclusions
V.I. Babkin and E.L. Skoryatina
Water resources, water use and water availability in North America
A.V. Izmailova
Introduction
Physical conditions
Geology, relief and landscapeClimateHydrology
Socio-economic conditions and the use of water resources
Population
Economic characteristics
Assessments of water use
Use of water resources
Hydrological data
Distribution of water resources in time and space
A.V. Izmailova and T.G. Markelova

158
158
158
159
161
166
168
168
170
175
183
188
188
192
197
201
201
203
216

217
217
218
218
219
220
224
224
224
226
227
235
237

viii

CONTENTS

7.5.1
7.5.2
7.5.3
7.5.4
7.6
7.6.1
7.6.2
7.6.3
7.7

Data and methods
Regional and national water resources
Drainage to the oceans and flows in the major rivers
The distribution of runoff within the year
Changes in water use and water availability
Data
Changes and trends in water use
The availability of water in the regions and in certain countries
Water management problems in North America: Canadian transfers
I.A. Shiklomanov and A.V. Izmailova
7.7.1 The background7.7.2 Problems of inter-basin transfers in Canada
7.8
Conclusions

237
239
242
249
252
252
257
264
267

8
8.1

286
286

8.2
8.2.1
8.2.2
8.3
8.4
8.5
8.5.1
8.5.2
8.5.3
8.5.4
8.6
8.6.1
8.6.2
8.6.3
8.7

9
9.1

Water resources, water use and water availability in South America
Introduction
V.I. Babkin and T.V. Grube
Physical conditions
V.I. Babkin and T.V. Grube
Relief, climate and vegetation
Hydrology
Socio-economic conditions and the use of water resources
N.V. Penkova
Hydrological data
V.I. Babkin T.V. and Grube
Distribution of water resources in time and space
V.I. Babkin, T.V. Grube and T.G. Markelova
Data and methods
Estimates of the water resources of regions and countries
River flow and drainage to the oceans
The distribution of runoff within the year
Changes in water use and water availability
N.V. Penkova and I.A. Shiklomanov
Data
Changes and trends in water use
Water availability
Conclusions
V.I. Babkin and T.V. Grube

Water resources, water use and water availability in Australia and Oceania
Introduction
T.Ye. Grigorkina
9.2
Physical conditions
T.Ye. Grigorkina
9.2.1 Relief, climate and vegetation
9.2.2 Hydrology
9.3
Socio-economic conditions and the use of water resources
N.V. Penkova
9.4
Hydrological data
T.Ye. Grigorkina

267
272
284

287
287
288
290
295
297
297
299
300
311
312
312
315
318
321

322
322
322
322
324
326
330

CONTENTS

9.5
9.5.1
9.5.2
9.5.3
9.5.4
9.6
9.6.1
9.6.2
9.6.3
9.7
9.8

10
10.1
10.2
10.3
11
11.1
11.2
11.3

Distribution of water resources in time and space
T.Ye. Grigorkina and T.G. Markelova
Data and methods
Water resources for regions and countries
Drainage to the oceans
Distribution of runoff during the year
Changes in water use and water availability
N.V. Penkova and I.A. Shiklomanov
Background
Trends in the use of water
Water availability
Major economic problems due to stresses on water resources
T.Ye. Grigorkina
Conclusions
T.Ye. Grigorkina
Global renewable water resources in space and time
I.A. Shiklomanov
Review of existing assessments: initial data
Estimating water resources
Flows to the World Ocean
World water use and water availability
I.A. ShiklomanovAnalysis of the available estimates and predictions
Trends in world water use
Water availability and water stress12

Climate change and water resources
V.Y. Georgiyevsky and I.A. Shiklomanov12.1
Introduction
12.2
Global climate change: the essence of the problem
12.3
Climate change scenarios
12.4
The likely impact of climate change on water resources
12.5
Current basin responses to climate change
12.6
The influence of climate change on water resources and water requirements
12.6.1 Climate change and runoff
12.6.2 Changes in climate, water requirements and water use
12.7
Conclusions

ix
331
331
332
337
338
341
341
346
346
348
350

352
352
355
366
369
369
375
384
390
390
390
393
396
398
402
402
410
412

General conclusions: the outcome of the Monograph
I.A. Shiklomanov

414

References

417

1

The Earth and its physical features

1.1 PHYSICAL GEOGRAPHY
1.1.1 The area of the Earth’s surface
The total area of the surface of the Earth is 510 million km2 . Over361 million km2 or 71% of this area is occupied by the World
Ocean and only 149 million km2 or 29% is covered by land. Waterand land are distributed unevenly over the globe. In the Northern
Hemisphere land extends over 100 million km2 (39% of its area),
while there are 49 million km2 in the Southern Hemisphere (19%).
The area of water in the Northern Hemisphere is 155 million km2(61%), and in the Southern 206 million km2 (81%).

1.1.2 The World Ocean
The World Ocean is divided into four separate oceans by the distribution of the land (Stepanov, 1983): namely the Pacific, Atlantic,
Indian and Arctic Oceans, and into numerous seas, gulfs, bays
and straits. The Southern Ocean is also identified but is lesswell defined than the others. Basic information on the oceans
and seas (Korzun, 1974b) are presented in Tables 1.1 and 1.2
respectively. The volume of water in the World Ocean is about
1340 million km3 .

1.1.3 Continents and islands
During the present geological epoch the Earth’s land consists ofsix continents: Eurasia, Africa, North America, South America,
Australia and Antarctica. The borders between the separate continents are rather arbitrary. The border between Eurasia and Africa
passes through the Strait of Gibraltar, along the MediterraneanSea, Suez Canal, Red Sea, and the Straits of Bab el Mandeb.
The boundary between North and South America passes throughthe Panama Canal. In this Monograph, Eurasia is subdivided into
two parts which are considered as independent: namely Europe
and Asia. The border between these continents extends from
Matochkin Shar, in the north, along Pay Khoy, the Ural Mountains,
Mugodzhary, along the River Emba, and the north and west coastof the Caspian Sea and Caucasus Mountains. Information on
the continents and largest islands is given in Tables 1.3 and 1.4(Terehov, 1981).
PRIMARY WATERSHEDS

Primary and secondary watersheds can be identified on the land
surface. The primary watershed divides the land into two: the firstcarrying runoff to the Atlantic and Arctic Oceans (60% of the landarea) and the second where runoff occurs to the Pacific and Indian
Oceans (40%). The secondary watersheds are those surrounding
the basins of the Pacific, Atlantic, Indian and Arctic Oceans andthose delineating areas of internal runoff.
The primary watershed extends northwards from Cape Hornalong the Andes and the Rocky Mountains to the Bering Strait,
then across the eastern plateau of Asia in a westerly direction, andthen it turns to run along the eastern edge of Africa to finish at theCape of Good Hope.
The watersheds of ocean basins are located on individual continents in the following way. In Europe the watershed between the
Arctic and Atlantic Oceans passes from the southwest coast of
Norway along the Scandinavian Uplands, through the Manselkya
Highland, and between Segozero and Onega. The watershed line
between the Atlantic Ocean and the area of internal runoff to
the Caspian Sea passes between Lakes Onega and Beloye Ozero,along the Valdai Hills, through the Central Russian and the
Privolzhskaya Uplands, to Ergeny and the Caucasus Mountains.
In Asia the watershed between the Atlantic and Indian Oceans
extends from the south end of the Suez Canal to the source of theEuphrates River. Then the watershed between the Indian Ocean
and the area of internal runoff to the north passes along the Plateau
of Serkhed, through the Hindu Kush, and from the southern partof Tibet to the Kukushili Mountains to meet the Pacific Ocean watershed. The main watershed of the basins with rivers flowing into
the Pacific Ocean passes from Cape Dezhnev along the Chukot,
Kolyma, Dzungur, Stanovy, Yablonovy and Hentey Ranges, along
the highlands of the northern area of the Gobi and further along
Great Khingan Mountains, Inshan, Nan Shan, Kukushili, Tanghla,
Henduanshan, to Bilau.

1

2

THE EARTH AND ITS PHYSICAL FEATURES

Table 1.1. Major hydrological and morphometric characteristics of the World Ocean

Ocean

Total area(with islands),
km2 × 106

Area ofwater surface,
km2 × 106

Area ofcatchment,
km2 × 106km3 × 106%

Average

Maximum

Pacific
Atlantic
IndianArctic

182.6
92.7
77.0
18.5

178.7
91.7
76.2
14.7

24.9
50.7
20.9
22.5

707.1
330.1
284.6
16.7

53.4
24.6
21.0
1.0

3957
3602
3736
1131

11 034
9 219
7 450
5 220

World Ocean

370.8

361.3

119.0

1338.51003704

11 034Area,
km2 × 103

Volume,km3

Water volume

Depth, m

Table 1.2. Major morphometric characteristics of seas

Sea

Area,
km2 × 103

Volume,km3

Sea

Coral Sea
South China Sea
Bering Sea
Sea of Okhotsk
Sea of Japan
East China Sea
Yellow Sea
Banda Sea

4791
3447
2344
1617
1070
752
417
695

Pacific Ocean
11 470Java Sea
3 929
Sulawesi Sea
3 796
Sulu Sea
1 317
Molucca Sea
1 630
Seram Sea
263
Flores Sea
17
Bali Sea
2 129
Savu Sea

480
435
348
291
187
121
119
105

22
1586
553
554
227
222
49
178

Caribbean Sea
Mediterranean Sea
Gulf of Mexico
Hudson Bay
Baffin Bay

2754
2505
1543
819
689

Atlantic Ocean
6 860
North Sea
3 754
Baltic Sea
2 332
Black Sea92
Sea of Azov
593
Sea of Marmara

554
448
431
40
11

52
20
555
0.4
4.0

Arabian Sea
Bay of Bengal
Arafura Sea

3683
2172
1037

Indian Ocean
10 070
Timor Sea
5 616
Andaman Sea
204
Red Sea

615
602
450

250
660
251

Barents Sea
Norway Sea
Greenland Sea
East Siberian Sea

1470
1547
1205
926

Arctic Ocean
268
Kara Sea
2 408
Laptev Sea
1 740
Chukchi Sea
61
Beaufort Sea
White Sea

903
678
590
476
91

101
363
45
478
4.4

The watershed of the rivers draining to the Arctic Ocean in Asia
passes from the northern end of land in the Strait of Matochkin
Shar, along the Pay Khoy Range and the Ural Mountains, to theinterfluvial area of Tobol, Turgay, Ishim, and to the Kazakh areaof low hills, onwards to the ranges of Tarbagatay, Mongolian
Altai, Tank Ola, Hangay and Hentey, and then it extends along
the watershed of rivers draining to the Pacific Ocean.

In Africa the watershed between the basins of Atlantic andIndian Oceans passes from the Gulf of Suez along the peaks ofmountains situated besides the Red Sea, along the eastern partof the Abyssinian Highlands, to the east of Lake Victoria between Lake Tanganyika and Lake Nyasa, along the Muchinga
Mountains, between the Rivers Congo and Zambezi, Cubango
and Cunene, westwards and southwards of Lake Etosha, along

3

PHYSICAL GEOGRAPHY

Table 1.3. Morphometric characteristics of continents

Continent
EuropeAsia
AfricaNorth America
South America
Australia and Oceania
Antarctica

Altitude above sea level, mArea withislands, km2 × 106

Area ofislands, km2 × 106

Average

Maximum

Minimum

10.5
43.5
30.1
24.2
17.8
8.9
14.0

0.7
2.7
0.6
4.1
0.1
1.3
0.058

300
950
750
700
580
350
2040

5642
8848
5895
6193
7014
5029
5140

−28
−392
−150
−85
−35
−12
–

Damaraland, across the hills of the southwest and the southernborders of the Kalahari Desert, through the Drakensberg Mountains to Cape Agulhas.
In North America the watershed between the Arctic Ocean
and the Pacific and Atlantic Oceans passes from Cape Prince ofWales along the Brooks Range, through the Richardson Mountains, Seluin, and Rocky Mountains, along the uplands between
the Mississippi and Nelson Rivers, northwards of Lake Superiorand Lake Huron and along the Labrador Peninsula. The watershed between the Atlantic and Pacific Oceans passes along theRocky Mountains, around the upper parts of the Mississippi andSouth Saskatchewan, along the Isthmus of Tehuantepec and to the
Panama Canal.
In South America the watershed separating runoff to the
Atlantic and Pacific Oceans starts at the Panama Canal and passes
along the Andes, through the Strait of Magellan along Tierra delFuego to its southern tip.
In Australia the watershed between the basins of Pacific andIndian Oceans passes from Cape York along the Great Dividing
Range to South East Point (Cape Otway).
Excluding the areas of internal runoff, the Arctic Ocean takes
15% of the runoff from the total land area of the globe, the Atlantic
34%, the Pacific 17% and the Indian Ocean 14%.
RIVERS

Depending on the size of the basin they drain, the length andvolume of the flowing water, rivers are usually subdivided intovery large, large, medium, small and very small. Table 1.5 presents
information on the morphology of the principal river basins of theearth.
The largest river in the world is the Amazon with a catchment area of 6915 thousand km2 , and length 6280 km. Its total annual runoff amounts to about 15% of the total runoff ofall the world’s rivers. Among very large rivers are the Congo(catchment area 3680 thousand km2 and length 4370 km) andMississippi (2980 thousand km2 and 4700 km). Over the world asa whole there are 20 rivers with catchment areas between 3 million

to 1 million km2 and 89 rivers with basin areas from 1 million km2 to 100 000 km2 . Most rivers are amongst the medium,small and very small categories. About 80% of the land surface drains to the World Ocean, while the area of internal runoff
where the rivers do not reach the ocean accounts for 20% of
the land surface. Most of the world’s largest rivers drain to theocean.
In Europe the area of internal runoff consists of the Caspian Sea
basin, which includes the basins of Volga, Ural, and Kura Rivers.
In Asia the area of internal runoff is larger and includes: the basinof the Aral Sea (Amu Darya, Syr Darya Rivers) the basin of Lake
Balkhash (Ili River) and many rivers flowing into small lakes ordisappearing in arid areas (Tedzhen, Murgab, Sary-Su, Turgay,
Irgiz and Nura Rivers). There are also the deserts of Alashan,
Gobi, and Takla-Makan in Central Asia, while parts of Asia Minorand most of the Arabian Peninsula have areas of internal runoff.
There are several closed basins situated in the interfluvial area of
the Indus and Ganges.
Almost one-third of Africa drains internally. These are the
Sakhara, Libyan, Nubian, Kalahari, and Namib Deserts and semideserts, together with the basins of Lakes Chad, Rukwa andTurkana.
In North America the Great Basin (including Great Salt Lake),the deserts of the Mexican Plateau, the Colorado Plateau and theright bank of the Rio Grande have no outlets to the ocean, while
in South America the internal runoff areas include the basins of
the Lakes Titicaca–Poopo, the Puna de Atakama Desert, the semidesert plateau of Patagonia and other territories.
In Australia Lakes Eyre, Amadeus, Torrens and Frome areclosed, as well as the Great Sandy Desert, Gibson Desert and Great
Victoria Desert. Little is known about drainage on the Antarctic
continent.
The total area of internal runoff (Korzun, 1974b) amounts
to 30.2 million km2 , including Europe 2.2 million km2 , Asia
12.3 million km2 , Africa 9.6 million km2 , Australia 3.9 million
km2 , South America 1.4 million km2 and North America
0.88 million km2 .

4

THE EARTH AND ITS PHYSICAL FEATURES

Table 1.4. Principal islands of more than 10 000 km2 in area

IslandArea,
km2 × 103

EuropeGreat Britain
Iceland
Ireland
Novaya Zemlya Islands
Spitsbergen Islands
SicilySardinia
Franz Josef Land

230.0
103.0
84.4
81.3
62.1
25.4
23.8
16.1

Asia
Kalimantan
SumatraHonshuSulawesi
Java
Luzon
Mindanao
Hokkaido
Sakhalin
Sri Lanka
KyushuNovosibirsk Islands
Severnaya Zemlya Islands
TaiwanHainan
Timor
ShikokuSeramHalmahera
Kuril Islands
Sumbawa
FloresPalawanBangka
Sumba

735.7
435.0
223.4
179.4
126.5
105.6
95.6
77.7
76.4
65.6
42.6
38.4
37.6
35.9
33.7
33.6
18.8
18.2
18.0
15.6
15.5
15.2
11.8
11.6
11.2

AfricaMadagascar

587.0

LAKES

Lakes are widespread on all continents. There are about 15 millionof them, and the total water surface area is about 2 million km2
or 1.5% of the land area (excluding the Antarctic). Most of thelakes are small and very small. Across the world there are 88 large
lakes with a water surface area exceeding 1000 km2 . Of these lakes

IslandNorth America
GreenlandBaffin Island
Victoria Island
Ellesmere Island
Cuba
Newfoundland
Haiti
Banks Island
Devon Island
Southampton Island
Melville Island
Alexander Archipelago
Axel Heiberg Island
Prince of Wales Island
Vancouver Island
Somerset Island
Aleutian Islands
Prince Patrick Island
The Bahamas
Jamaica
Queen Charlotte Islands
Cape Breton
South America
Tierra del Fuego
Falkland Islands(Islas Malvinas)

Area,
km2 × 103
2176.0
519.0
213.8
202.7
105.0
111.0
77.2
69.9
56.4
44.1
42.1
36.8
34.4
33.3
32.1
24.3
17.7
15.8
11.4
11.1
10.3
10.3
48.0
12.0

Australia and Oceania
New Guinea
New ZealandTasmania
Solomon Islands
New Britain
Fiji Islands
Hawaii
New Caledonia
New Hebrides
Bougainville Island

829.3
265.3
68.4
40.4
36.6
18.2
16.7
16.7
14.8
10.0

Antarctica
Alexander I Land

43.2

28 are located in Asia, 13 in Europe, 16 in Africa, 22 in North
America, 5 in South America and 4 in Australia. The number oflakes with a surface area greater than 10 000 km2 is 19; 1 in Europe(Lake Ladoga), 4 in Asia (Aral, Baikal, Balkhash, Tonle Sap),
4 in Africa (Victoria, Nyasa, Chad, Turkana), 8 in North America(Superior, Huron, Michigan, Great Bear Lake, Great Slave Lake,

5

PHYSICAL GEOGRAPHY

Table 1.5. Major morphometric characteristics of principal world rivers
Area ofcatchment,
km2 × 103

Length, km

Volga
DanubeDnieper
Don
North Dvina
Pechora
Neva
Rhine
Ural
Vistula
Elbe
Loire
Odra
Rhône
Neman

1380
817
504
422
357
322
281
252
236
198
148
120
119
98
98

3700
2850
2200
1870
1302
1809
74
1320
2534
1092
1165
1010
907
812
937

Ob
Yenisey
Lena
Amur
Yangtze
Ganges with
Brahmaputra
and Meghna
Amu Darya
Indus
MekongHuang He
Shatt al Arab
(Tigris andEuphrates)
KolymaXi Jiang
Tarim
Syr Darya
Irrawaddy
Khatanga
Indigirka

2990
2580
2490
1855
1808
1746

3650
3490
4410
2820
6300
5425

1100
960
795
752
750

1415
3180
4500
5464
2900

647
454
446
440
410
364
360

2130
2214
2000
2210
2300
1634
1726

Congo
Nile
Niger
ZambeziOrangeChari
Okowango

3680
2870
2090
1330
1020
880
785

4370
6670
4160
2660
1860
1400
1800

River

Area ofcatchment,
km2 × 103

Length, km

DouroDaugava
Garonne
Ebro
Tagus
Seine
Mezen
Po
Dniester
GuadianaSouth Bug
Kuban
Guadalquivir
Onega

95
88
56
87
81
79
78
75
72
72
64
61
57
57

938
1020
650
928
1010
776
966
652
1352
801
792
907
680
416

SalweenGodavari
Huai He
Krishna
HelmandYana
Liao He
OlenekAnadyr
Kura
Pyasina
Chao Phraya
Taz
Songka (Red)
Mahanadi
Ili
TaimyraKerulen
Pur
AnabarNarmada

325
313
270
259
250
238
229
219
191
188
182
160
150
145
142
140
124
120
112
100
99

2820
1465
1000
1401
1150
872
1390
2270
1150
1360
818
1200
1400
1185
851
1000
754
1264
389
939
1312

Ogowe
GambiaRufijiCuanzaRuvumaQui HonSanaga

203
180
178
149
145
137
135

850
1200
1400
630
800
830
860

River

EuropeAsia

Africa6

THE EARTH AND ITS PHYSICAL FEATURES

Table 1.5. (cont.)
Area ofcatchment,
km2 × 103

Length, km

Juba
SenegalLimpopo
Volta

750
441
440
394

1600
1430
1600
1600

Mississippi
Mackenzie
NelsonSt. Lawrence
Yukon
Columbia
Colorado
Rio Bravo delNorte
Churchill
Fraser
Telon
Albany

2980
1787
1132
1026
850
668
637
570
298
233
142
134

North America
3780
Koksoak
5472
Rio Grande de
2574
Santiago
3057
Brazos2897
Mobile1953
Colorado
2333
Mus
2880
Hais
Goalzas1609
Severn1370
Fort George–
Saguenay
975
PanukoAmazonLa Plata
OrinocoSão Francisco
Parnaı́ba
Magdalena
Essequibo

6915
3100
1000
600
325
260
155

South America
6280
Chubut4700
Rio Negro
2740
Rio Dose
2800
Rio Colorado
1450
Paraı́ba
1530
Atrata970
Bı́o Bı́o

MurrayCooper Creek
Diamantina
Fitzroy
Burdekin
Flinders
Ashburton
Sepik

1072
285
115
143
131
108
82.0
81.0

3490
2000
896
960
680
930
640
1120

River

River
Savi
Bandoma
Wad DraTanaAustralia
Gascoyne
Victoria
MitchellMurchison
Fly
Fortescue
Kluta

Erie, Winnipeg, Ontario), 1 in South America (Maracaibo), and
1 in Australia (Lake Eyre).
Most lakes are situated in the Northern Hemisphere and arelocated in glaciated areas (there are many small lakes in the tundra). Many lakes of Europe (e.g. Ladoga and Onega) are situated in large basins, often grabens where the northern sides wereeroded by ice. Tectonic depressions, glacial erosion and moraine
dams form many lakes in Sweden: Vanern, Vattern, Malaren,

Area ofcatchment,
km2 × 103

Length, km

107
97
95
91

680
780
1150
720

133
125

1300
960

118
116
110
108
108
106
101
98
90
84

2060
1250
1390
–
–
–
976
–
–
–

138
130
81
65
59
32
24

850
1000
600
1000
800
644
380

79
77
69
68
64
55
22

770
570
520
700
1040
670
338

for example. There are many lakes formed by glacial dams in
the northwest of Russia, and in Finland, Poland, Germany andCanada. A large group of lakes in the south of Finland (e.g.
Lakes Saimaa and Paijanne) are divided from the Gulf of Finland
by a huge dam made of a double ridge of terminal moraines,
known as Salpa-Uselka. The chain of large lakes in North America(Lake Winnipeg, Lake of the Woods, and the Great Lakes:
Superior, Huron, Michigan, Erie and Ontario) lie behind morainic

7

PHYSICAL GEOGRAPHY

deposits left by the receeding ice, which covered the whole of thenorth of the North America continent. A group of alpine lakes(Lake Geneva, Lake Maggiore and Lake Garda) are located in theglacially eroded basins at the foot of the Alps.
A number of lakes are located in deep tectonic depressions inmountain areas such as Baikal (1741 m), Khubsugul (267 m),
Issyk Kul (702 m), Nyasa (706 m), and Titicaca (281 m). In themountain systems of the Tien Shan, the Pamirs and the Altai there
are many lakes formed from the blocking of river valleys with rockfragments during earthquakes. Among them are Lake Teletskoyein the Altai Mountains, and Lake Sarezskoye in the Pamirs in the
Murghab River valley (this lake was formed in 1911 as a result of
the Usoisky River being blocked).
The lakes in high mountain areas are often situated on plateauxsurfaces and are mainly of a tectonic origin. Among the large
lakes are Lakes Victoria (altitude 1136 m above sea level) andTanganyika (773 m) in Africa; Titicaca (3812 m) in SouthAmerica; Kara Kul (3954 m) and Chatyr Kul (3486 m) on the
Pamirs, and Issyk Kul (1609 m) on the Tien Shan in Asia. One of
the highest lakes is Lake Horpatso, situated in Tibet at an altitudeof 5400 m.
The Caspian Sea (−27 m), and the Dead Sea (−392 m) aresituated in deep depressions below sea level. The Caspian Sea
and a number of other large lakes (Lakes Balkhash, Balaton etc.)
are relics of former more extensive water bodies that appeared
after the recession of the ice sheets.
Numerous small lakes are formed by wind action (aeolian lakes)
in the hot, dry climate of the steppes such as in Western Siberia andKazakhstan. In regions where limestone, dolomite and gypsum
formations dominate the geology, there are karstic lakes, and inareas of permafrost there are thermokarstic lakes. These form
when buried ice melts. Lakes of volcanic origin are frequent in
Kamchatka, in the Kuril Islands, in the Armenian Highlands, in
Middle and Central Asia, and in New Zealand.
Table 1.6 shows the morphological characteristics of the largest
lakes. The total volume of water stored in the world’s lakes is
176 400 km3 ; salt lakes account for 85 400 km3 and fresh lakes
for 91 000 km3 . The largest volume of saline waters (91% of thetotal volume) is found in a single water body – the Caspian Sea.
In Asia, the volume of salt lakes is only 3% of the volume of theworld total; the volume of fresh waters in Asia is almost 10 times
greater than the salt lakes, because of Lake Baikal which holds
27% of the total volume of the world’s freshwater lakes.
In Africa all the large lakes are fresh. Lake Chad situated on
the edge of the Sahara, although highly mineralized, is not related to the salt lakes. In North America among the salt lakes
is the Great Salt Lake, while in South America Lake Poopo andLake Titicaca are not salt lakes, but their water cannot be used for
drinking.

RESERVOIRS

During the twentieth century the numbers of reservoirs increased
markedly. They are used for public water supply, irrigation, hydropower generation and for other purposes. By the late 1980s,
Avakyan et al. (1987) estimated there were about 30 000 reservoirs across the world with a volume of greater than 1 million m3 .
There were 2500 reservoirs with a capacity larger than 100 million m3 , accounting for more than 90% (or 5750 km3 ) of both thetotal volume and the total surface area of all the world’s reservoirs. According to the estimates available, the total volume ofsuch reservoirs now exceeds 5750 km3 , and the total surface area
is about 400 000 km2 .
The large reservoirs constructed during the twentieth century
since 1950 have substantially transformed the volume and patternof fresh water stored on the land surface. They also allowed thedevelopment and maintenance of a large number of inter-basintransfer systems (Vugeinsky, 1991).
Of the world’s reservoirs, most are valley reservoirs, which are
created by damming the river channel. The biggest valley reservoir
in the world in terms of volume is the Bratskoye Reservoir on theRiver Angara (169.3 km3 ), and in terms of water surface area
the Volta on the Volta River (8480 km2 ). Since 1950, cascades ofreservoirs have been constructed on many large rivers such as the
Nile, Yenisei, Colorado, Euphrates, Huang He, Zambezi, Volga,
Parana, Mississippi and Missouri.
Reservoirs have also been built by constructing a dam to raise
the water level of an existing lake, for example, in Finland, in thenorthwest of the European part of Russian, and in East Africa.
The largest reservoir of this type is Lake Victoria, where the damat the Owen Falls harnesses a storage of 204.8 km3 and a surface
area of 68 800 km2 .
Along with these two types of reservoirs there are also ones
filled in natural depressions by diverting water from a river or bypumping. The largest reservoir in the world of this type is WadiTartar in Iraq having a volume of 72.8 km3 and a surface area of2000 km2 .
Reservoirs differ widely in their usage. Hydropower reservoirs
are numerous in Africa and South America. In Asia and Latin
America there are reservoirs that are used primarily for irrigation.
Besides the above usage, many reservoirs on the planet are madefor public water supply. In addition there are the reservoirs constructed for navigation, flood protection, fisheries, recreation, timber rafting, and for a variety of different needs. In recent decades
multi-purpose reservoirs have been constructed in many parts of
the world.
The greatest proportion of the world total volume of stored
water is made up from the reservoirs of the USA, Russia, Canada,
India and China. Information on reservoirs with a capacity of morethan 20 km3 is given in Table 1.7.

8

THE EARTH AND ITS PHYSICAL FEATURES

Table 1.6. Major morphometric characteristics of principal world lakes

Area, km2

Maximum
depth, m

Volume, km3

EuropeCaspian Seaa

378 000

1025

78200

LadogaOnega
Vänern
Chudsko-PskovskoyeVättern
Suur-Saimaa
MälarenPäijänne
Inari
Ilmen
BalatonGenevaBodensee18 135
9 890
5 648
3 558
1 856
1 800
1 140
1 116
1 116
982
593
584
539

230
120
106
15.3
122
58
61
95
92
4
12
310
252

908
295
153
25.2
74
36.0
14.3
18.1
15.9
12
1.9
88.9
48.5

484
464

22
74

2.9
7.38

64 10031 50018 20010 100c
6 280
6 000d
5 800
5 510
4 560
4 220
4 190
3 760
3 500
3 350
2 770
2 700
2 650
2 500
2 500
2 460
2 210
1 760
1 590
1 360
1 110
454
380
245

68
1741
25
12
702/668
10
16
10
26
38
11
145
5
–
207
20
54
10
–
–
–
–
8
86
529
27
238
128

1020
23000
106
40
1730
–
45
53.0
13
–
18.5
–
(5)
–
381
–
58.6
4.3
–
–
–
–
–
58.5
1258

Lake

HjamarenStorsjon
Asia
Aral Seaa,bBaikalBalkhasha
Tonle Sap
Issyk Kula
Dongting Hu
Rezaieh (Urmia)a
ZaisanTaimyrKoko Nor a
KhankaVana
Lop NorUbsu Nur a
Khubsugul
Poyang Hu
AlakolaChanyaTuza
Nam Coa
Tai HuKara-Us-Nur
Tengiza
Sevan
Toba
Marka Kul
Kara Kul
Teletskoye–
40

Country

Russia, Kazakhstan,Azerbaijan, Iran,
Turkmenistan
RussiaRussiaSwedenRussia, Estonia
SwedenFinlandSwedenFinlandFinland
RussiaHungary
Switzerland, France
Germany, Austria,
Switzerland
SwedenSwedenKazakhstan, Uzbekistan
RussiaKazakhstan
Cambodia
Kirghizia
China
Iran
Kazakhstan
RussiaChina
Russia, China
TurkeyChina
Mongolia
Mongolia
China
Kazakhstan
Kazakhstan
TurkeyChina
China
Mongolia
Kazakhstan
Armenia
Indonesia
Kazakhstan
Kirghizia
Russia9

PHYSICAL GEOGRAPHY

Table 1.6. (cont.)

Area, km2

Maximum
depth, m

Volume, km3

AfricaVictoria
Tanganyika

68 80032 000

84
1471

2 750
17 800Nyasa

30 900706

7 725

10 000–25 000e
8 660
5 300
5 100
4 920 f
4 500
3 150
2 370
2 325
2 325
1 270
1 160
1 040
765
620
600
551
530
434
409

10–11
73
58
15
5
–
14
496
112
6
60
13
2.6
–
14
12
13
3
7
266

72
–
280
32.0
5.0
–
28.0
569
78.2
–
14
8.20
45.0
–
3.72
–
–
0.90
1.10
37

84 50063 50058 00031 40028 60025 80024 40019 300
8 030
7 940
6 640
5 360
4 700
4 660
4 410
3 830
2 190
1 490
1 200
1 190
1 080

406
229
281
137
156
64
19
236
70
60
–
12
28
14
21
–
120
26
7
3
10

11 600
3 580
4 680
1 010
1 070
545
127
1 710
108
110
–
16
17
19
–
–
–
7.97
5.3
–
10.0

Lake

Chad
Turkana
AlbertMweru
Bangweulu
Rukwa
Tana
Kiwu
EdwardLeopold II
KatnitAbaya
ShirwaTumba
Faguibini
Gabel-Aulia
Chamo
UpembaZwoi
ShallaNorth America
Superior
Huron
Michigan
Great Bear Lake
Great Slave Lake
Erie
Winnipeg
Ontario
Nicaragua
Athabasca
Reindeer Lake
Winnipegosis
Manitoba
Great Salt Lakea
Lake of the Woods
Dubawnt
Mistassini
ManaguaSaint Clair
Small Slave Lake
ChapalaCountry

Tanzania, Kenya, Uganda
Tanzania, Zaire, Zambia,
Rwanda, Burundi
Malawi, Mozambique,Tanzania
Chad, Niger, Nigeria
Kenya
Uganda, Zaire
Zambia, Zaire
ZambiaTanzania
Ethiopia
Zaire, Rwanda
Zaire, Uganda
Zaire
Nigeria
Ethiopia
Malawi
Zaire
Mali
Sudan
Ethiopia
Zaire
Ethiopia
Ethiopia
Canada, USA
Canada, USA
USA
CanadaCanadaCanada, USA
CanadaCanada, USA
Nicaragua
CanadaCanadaCanadaCanadaUSA
Canada, USA
CanadaCanadaNicaragua
CanadaCanadaMexico10

THE EARTH AND ITS PHYSICAL FEATURES

Table 1.6. (cont.)

Area, km2

Maximum
depth, mSouth America
Maracaibo
Titikaka
PoopoaBuenos Aires
Argentino
Valencia

13 300
8 372
2 530
2 400
1 400
350

35
281
3
–
300
39

–
893
2
–
–
6.3

Venezuela
Peru, Bolivia
Bolivia
Argentina, Chile
Argentina
Venezuela

Australia
Eyre
Amadeusa
Torrens
Gairdner
GeorgiTaupo

15 000
8 000
5 800
4 780
145
611

20
–
–
–
3
164

–
–
–
0.3
60

New Zealand

Lake

Volume, km3

CountryaSalt lake.
Area of the Aral Sea water surface is given before reducing its level.
cWith low levels 3000 km2 , with high levels 30 000 km2 .
dWith low levels 4000 km2 , with high levels 12 000 km2 .
eWith low levels 7000–10 000, with high levels 18 000–25 000 km2 .
fWith low levels 4000 km2 , with high levels 15 000 km2 .
b

1.2 THE HYDROSPHERE
1.2.1 The origins of water on the Earth
The hydrosphere1 surrounding the Earth includes liquid, solid andgaseous forms of water. The hydrological cycle transports this water about the Earth exchanging energy and moving materials as
part of the process. The hydrosphere unity is determined by not
only its continuity but also the constant water exchange between
all its elements. The hydrosphere includes all types of natural
waters – oceans, seas, rivers, lakes and glaciers, underground, atmospheric and biologically combined waters. The lower limit of
the hydrosphere is assumed to be at the level of Mokhorovichichsurface, and the upper limit practically coincides with the upper
atmospheric limit (Blyutgen, 1972). Sea, lake, river, glacier, underground and atmospheric waters are all interrelated and water
moves from one situation to another as the hydrological cycle
progresses (Glushkov, 1929; Vernadsky, 1967).
The Earth’s hydrosphere is one of the oldest mantles of thisplanet and it appeared between 3.5 and 4 billion years ago (Klige
et al., 1998). It developed together with and in close relationshipto the lithosphere, the atmosphere, and then with life itself. Up
to the present the mechanisms of the origin of water on the Earthhave not been completely explained (Kotwicki, 1991). However,the degasification theory seems to be the most likely explana-tion (Rubey, 1951; Vinogradov, 1959; Artyushkov, 1970; Condie,
1989). According to this theory the basic mass of the hydrosphere
formed as a result of the processes of melting and degassing the
Earth’s mantle and it was determined by geophysical processes
operating at depth.
The mechanism is assumed to be that water vapour, the carbon
compounds CO2 , CO and CH, ammonia, sulphur and its compounds H2 S and SO, acid halides HCl, HF, HBr, boric acid, hydrogen, argon and some other gases came to the Earth’s surface
during lava degassification (Monin and Shishkov, 1979; Holland,1989). The largest part of the volcanic gases condensed and wastransformed into water, forming the hydrosphere.
Acid vapours HCl, HF, HBr, ammonia, sulphur and its compounds, and a considerable part of the CO2 dissolved in drops ofcondensed water and fell as acid rain to the Earth’s surface. These
acid flows ran to low places (oceanic depressions) on the Earth’s
primary surface, at the same time reacting with underlying rocks
and taking out of them the equivalent amount of alkali and alkali
earths. Oceanic water appeared to be saline from the very beginning, and land waters fresh as a result of the leaching occurring in
1 There are different interpretations of term “hydrosphere” and viewpoints
on its origin (Hydrosphere, 1960; Belousov et al., 1972; Chebotarev, 1978;
Monin and Shishkov, 1979; L’vovich, 1986; Kotwicki, 1991; Hydrosphere,
1993a, b).

11

THE HYDROSPHERE

Table 1.7. Principal reservoirs in the world with the capacity of more than 20 km3Year offilling up

Dambackwater, m

Full volume,
km3

Usea

Victoria–Nile

1954

31

204.8

HFI

AngaraNile
Zambezi
Volta
Manicouagan
Caroni
Yenisey
TigrisPeace
Zeya
Zambezi
La Grande
La Grande
AngaraAngaraVolga
Tocantins
Caniapiscau
Wainganga
IrtyshEuphrareNeuguenTocantins
VilyuiHuang He
Kouilou
ColoradoSão Francisco
Colorado
Nechako
Churchill
NechacoNelsonVolga
Euphrates
Missouri
St. Lawrence
Yenisey
ParanaMissouriIli
BandamaEuphrates
Volga
NeuguenHuan He
Columbia
Don

1967
1970
1959
1965
1968
1986
1967
1976
1967
1974
1977
1978
1981
1977
1989
1959
1993
1981
1987
1967
1995
1977
1984
1972
1962
1992
1936
1979
1966
1952
1971
1953
1975
1961
1976
1956
1958
1978
1982
1962
1970b
1972
1970
1955
1977
1990
1976
1952

106
95
100
70
214
162
100
–
183
98
127
168
93
88
70
29
144
56
43
67
175
35
65
68
90
137
221
43
216
104
32
25
30
27
190
62
20
220
165
75
41
57
15
18
16
172
175
26

169.3
169
160.3
148
141.8
136.3
73.3
72.8
70.3
68.4
62
61.7
60.0
59.4
58.2
58.0
54.4
53.8
50.7
49.6
48.7
43.4
43.0
35.9
35.4
35
34.8
34.2
33.3
32.7
32.3
32.2
31.8
31.4
30.6
30.1
30.0
29.1
29.0
28.8
28.1
28
26.0
25.4
25.1
24.7
24.7
23.9

HNTWFR
IHANF
HNIFA
HNIF
HNS
H
HNTWSFR
SI
HSN
SHNTF
HINF
H
H
HNTWF
HNT
HNWIF
H
H

Reservoir

Continent

Country

Basin

Owen Falls(Lake Victoria)
Bratskoye
NasserKaribaVolta
Daniel Johnson
Guri
Krasnoyarskoye
Wadi-Tartar
WAC Bennet
Zeiskoye
Cabora Bassa
La Grande 2
La Grande 3
Ust-Ilimskoye
Boguchanskoye
Kuibyshevskoye
Serra Da Mesa
Caniapiscau
Upper Wainganga
Bukhtarminskoye
Ataturk
Serros Coloradeso
Tucurui
Vilyuiskoye
Sanmenxia
Kouilou
HooverSobradinho
Glen Canyon
KemanoChurchill Falls
NechacoJenpegVolgogradskoye
Keban
Garrison
Iroquois
Sayanskoye
ItaipuOahe
Kapchagaiskoye
KossouRazzaza Dyke
Rybinskoye
Loma de la Lata
Longyangxia
Mica
Tsimlyanskoye

AfricaUganda, Kenya,
Tanzania
RussiaEgypt
Zambia, Zimbabwe
Ghana
CanadaVenezuela
RussiaIraq
CanadaRussiaMozambique
CanadaCanadaRussiaRussiaRussiaBrazilCanadaIndia
Kazakhstan
TurkeyArgentina
BrazilRussia
China
Congo
USA
BrazilUSA
CanadaCanadaCanadaCanadaRussiaTurkeyUSA
USA, Canada
RussiaBrazil, Paraguay
USA
KazakhstanCôte d’Ivoire
Iraq
RussiaArgentina
China
CanadaRussiaAsia
AfricaAfricaAfricaN. America
S. America
Asia
Asia
N. America
Asia
AfricaN. America
N. America
Asia
Asia
EuropeS. America
N. America
Asia
Asia
Asia
S. America
S. America
Asia
Asia
AfricaN. America
S. America
N. America
N. America
N. America
N. America
N. America
EuropeAsia
N. America
N. America
Asia
S. America
N. America
Asia
AfricaAsia
EuropeS. America
Asia
N. America
Europe

HFNSR
HI
HI
H
HWN
HISN
H
IHSA
NHW
HASR
H
H
H
NH
HWFINTR
IH
SIWHA
HNA
HINTWR
H
HSNR
HA
HIF
SI
HNTWFR
H
HIA
HA
HFRWN

12

THE EARTH AND ITS PHYSICAL FEATURES

Table 1.7. (cont.)

Reservoir

Continent

Country

Basin

KenneyKhantaiskoye
Fort Peck
Xinanjiang
Ilia Solteira
Yacyreta
FurnasE1 Chocon

N. America
Asia
N. America
Asia
S. America
S. America
S. America
S. America

CanadaRussiaUSA
China
BrazilArgentina, Paraguay
BrazilArgentina

NechakoKhantaika
Missouri
Xinanjiang
ParanaParanaGrandeLimay

Year offilling up

Dambackwater, m

Full volume,
km3

Usea

1952
1975
1937
1960
1974
1991
1965
1975

104
50
76
100
85
41
96
65

23.7
23.5
23.0
21.6
21.2
21.0
20.9
20.2

H
HN
SHIN
HA
HN
HNI
HA
HIA

a

H, hydropower; N, navigation; W, water supply; I, irrigation; F, fishery; T, timber rafting; R, recreation; A, accumulation; S, struggle withinundations.
b
In 1970 the filling of the reservoir was stopped. The project reservoir capacity was not attained.

the upper zone of the Earth’s crust, remaining saline only in deep
areas.
Some scientists (Shoemaker, 1984; Alvarez, 1987) do not agreewith this theory on the origins of the hydrosphere. They consider
that the Earth has experienced during its history numerous collisions with comets that were potential sources of water.
Estimates of the amount of water formed in this way at earlystages of the evolution of the Earth vary from 4% to 40% (Chyba,1987) and some suggest even higher proportions (Hoyle, 1978) of
the volume.
Present-day geological studies have shown that the hydrosphere
existed during most geological periods (Markov, 1960; Strakhov,1963). According to calculations (Timofeyev et al., 1988) the
Earth’s mantle contains 28 × 109 km3 of water, which supports
degasification as the origin of the hydrosphere.
During the early history of the Earth degasification was more
intensive. The basic mass of the hydrosphere would probably haveformed during the first hundreds of millions of years. Oceans
appeared rapidly during this time (Kuenen, 1950).
However, Revelle (1955) was of the opinion that the oceans
appeared late and quickly. According to Schopf (1980), the major
volume of degasification occurred between 4.6 and 2.5 billion
years ago, and according to Sorokhtin (1974), the maximum rateof growth took place during the Lower Riphean.
New studies (Staudacher and Allegre, 1982; Hydrosphere,
1993a, b) show that the Earth degasified rapidly during the 50 million years after it originated. The results of further studies in thisarea have been generalized by Holland (1989) and Kump (1989).
During the Archean Period the Earth’s surface relief was subdued and water covered an area of about 500 million km2 (Klige,1992). There was a warm and humid climate without distinct latitudinal zones and with alternating periods when minor warming andcooling occurred together with glaciation (Monin and Shishkov,
1979). In the Proterozoic Era, photosynthesis became active withthe development of live matter in the hydrosphere (Alpatjyev,
1983).
The gradual increase in the land area with the growth of the
thickness of the Earth’s crust and the development of mountains
exerted a considerable effect on the hydrological cycle. At thistime conditions were more arid and ice sheets developed in distinct climatic zones, the hydrological cycle between the oceans,
atmosphere and land grew more active and a river network developed (Drozdov et al., 1981).
In the Palaeozoic Era the hydrological cycle became more complicated due to changes in the ratio between the area of ocean andland. During this period the ocean reached its greatest size in theOrdovician. Marine deposits show that this was the most powerful transgression in the history of the Earth. The land area was
72 million km2 or 50% of its present size. The sea level rose by
more than 250 m and 83% of our planet was covered by water(Klige, 1980). In contrast, the area of the land was greatest during
the Mesozoic when the sea level was 100 m lower than at present.
Simultaneously with the decrease in the size of the ocean andan increase in the elevation of the continents, as a result of thedevelopment of mountain-forming processes, climatic conditions
became more arid, runoff decreased, and a considerable part of thewater became locked up in ice sheets and glaciers. At this time thecharacter of the water cycle came close to the one that exists today.
By the Mesozoic the gaseous composition of the atmosphere hadchanged greatly, as a result of the increase in the amount of carbon
dioxide and oxygen due to the development vegetation and animal
life. There is evidence of boreal, humid and subtropical climateson land in the late Triassic (Razumikhin, 1976).
The recent great oceanic transgression started at the end of
the Jurassic Period and reached its maximum in the Cretaceous
Period. Since then the ocean has, in general, regressed and theland area has increased (by about 35 million km2 ), and this has
been accompanied by powerful mountain-building of the Alpine

13

THE HYDROSPHERE

Table 1.8. Water content in the hydrosphere

Area of distribution,
km2 × 103

Volume,km3 × 103

Water layer, m

Fraction of
total volume ofhydrosphere, %World Ocean
Ground water (gravity and capillary)Predominantly fresh ground water
Soil moisture
Glaciers and permanent snow cover:
Antarctica
Greenland
Arctic Islands
Mountainous regions
Ground ice of permafrost zone
Water in lakes:
Fresh
Salt
Swamp waterRiver stream water
Biological water
Water in the air

361 300
134 800
134 800
82 00016 227.5
13 9801 802.4
226.1
224
21 0002 058.7
1 236.4
822.3
2 682.6
148 800
510 000
510 000

1 338 000
23 400a
10 53016.5
24 06421 600
2 340
83.5
40.6
300
176.4
91.0
85.4
11.5
2.12
1.12
12.9

3700
174
78
0.2
1463
1546
1298
369
181
14
85.7
73.6
103.8
4.28
0.014
0.002
0.025

96.5
1.7
0.76
0.001
1.74
1.56
0.17
0.006
0.003
0.022
0.013
0.007
0.006
0.00080.00020.0001
0.001

30.1
0.05
68.7
61.7
6.68
0.24
0.12
0.86
–
0.26
–
0.03
0.006
0.003
0.04

Total volume of the hydrosphereFresh water

510 000
148 800

1 386 000
35 029.2

2718
235

100
2.53

100

Type of watera

Fraction of
fresh water, %––With no account of underground water of the Antarctic, approximately estimated at 2 million km3 , including predominantly fresh water ofabout 1 million km3 .

type on most continents. This has lead to an increasing in the rolefor continental water in the global water cycle.
More recently, wide fluctuations in the distribution of land andwater can be traced particularly in the Pleistocene, over the last
million years as a result of the change in climatic conditions accompanied by alterations to the water regime on the Earth’s surface. Cooling, which appeared periodically as a result of variationsin the amount of solar radiation coming to the Earth’s surface, led
to the formation of large continental glaciations. Glaciers accumulated huge masses of water – more than 60 million km3 , which
resulted in the lowering of the sea level by more than 100 m. At thesame time a considerable amount of moisture (up to 1 million km3 )was accumulated in the extensive closed drainage basins on thecontinents. There are also changes in the volume of ground waterwith storage increasing considerably during the humid periods.

1.2.2 The contemporary hydrosphere
There are no large disagreements in the estimates of the volume of the present hydrosphere (Korzun, 1974a; Kotwicki, 1991;
Hydrosphere, 1993a, b), since it is determined, basically, by theenormous volume of water contained in the World Ocean. The

volume of the hydrosphere is most frequently estimated to be1370 million km3 and this figure is practically equal to the water
volume in the World Ocean. However, as more information becomes available about the relief of the ocean bottom, particularly
for the Arctic Ocean, where underwater ridges have been discovered, there have been reductions to a total of 1338 million km3 ,
i.e. a reduction of 32 million km3 (Frolov, 1971). The total volumeof the hydrosphere, according to current data (Korzun, 1974) is1386 million km3 (Table 1.8). Fresh water in all its states makes
up only 2.53% of the total, of which 1.74% is in the ice sheets of
the Antarctic and the Arctic and in mountain glaciers.
In addition to free (gravitational) water, the lithosphere contains
a large amount of physically and chemically combined water. The
average content of the physically and chemically combined waters amounts to 3.5% of the rock weight, i.e. some 0.84 × 1024 g(Derpgolts, 1971). Combined water does not participate actively
in the hydrological cycle, at least at recognizable time-scales, andis not taken into account in this present study.
THE WORLD OCEAN

Table 1.8 shows that the World Ocean holds by far the largest
part of total volume of water on the planet. However, in recent

14

THE EARTH AND ITS PHYSICAL FEATURES

Table 1.9. Present-day glaciation of continents and islands ofthe Earth

RegionArcticGreenlandFranz Josef Land
Novaya Zemlya
Severnaya Zemlya
Arctic Islands
Canadian Archipelago
Spitzbergen (Western)
Small Islands
Total
EuropeIceland
Scandinavia
Alpes
Caucasus
Total

Area ofglaciers, km2

Water volume,km3

1 802 400
13 73524 42017 470226 090
148 825
21 240400
2 028 490

2 340 000
2 530
9 200
4 620
83 50048 40018 69060
2 423 500

11 785
5 000
3 200
1 430
21 415

3 000
645
350
95
4 090

Asia
Pamir-Altai
Tien Shan
Dzungarian Ala Tau, Sayan
Mountains
Eastern Siberia
Kamchatka, Plateau of Koryak
Hindu Kush
Karakoram Pass
Himalayas
Tibet
Total

11 255
7 115
1 635

1 725
735
140

400
1 510
6 200
15 67033 15032 150109 085

30
80
930
2 180
4 990
4 820
15 630

North America
Alaska (Pacific Coast)
Inner Alaska
USA
MexicoTotal

52 000
15 000510
1267 52212 2001 800
60
214 062South America
Venezuela, Colombia, Andes,
Tierra del Fuego
Patagonian Andes
Total

7 100

2 700

17 90025 000

4 050
6 750

Oceania
New Zealand
New Guinea
Total

1 000
14.5
1 014.5100
7107

AfricaKenya, Mount Kilimanjaro,
Ruwenzori
Antarctica

years, studies have appeared (Sofer and Skirstymonskaya, 1994;
Wallace, 1996) that show volumes which differ from the data
here by between 0.7% and 10%. Including the water stored in thebottom silts of the oceans causes the 10% difference.
The World Ocean has accumulated 3.06 × 1025 Joules of heat
(Stepanov, 1983). Every year it takes up almost twice as muchsolar energy as the land, and this factor determines its importantrole in the planetary heat exchange. The major portion of thisenergy is employed in evaporating over 500 000 km3 per year ofwater, which ensures global water exchange.

GLACIERS AND ICE SHEETSThe largest volume of fresh water is stored in the planet’s glaciersand ice sheets. The total area of the present glaciation exceeds
16.2 million km2 (Kotlyakov, 1997). The mean ice thickness on
this area is 1700 m, and the maximum is more than 4000 m (inAntarctica). The distribution of ice sheets and glaciers and thewater stored in them is given in Table 1.9. The data on glacier
thickness and water storage are approximate. To estimate the mean
thickness of ice data were used from the few measurements fromice drilling and seismic sounding (Korzun, 1974b). These data
were applied by analogy to other glaciers taking into account theirmorphological features. The accuracy of the assessment of thatwater storage in the Antarctica, for example, is about ±3.0 million km3 . The total water volume in the ice across the globe is
estimated to exceed 24 million km3 (Korzun, 1974b). Most of thewater stored in the ice cover is concentrated in Antarctica (almost90%), while the remainder is found in Greenland (almost 10%)and in mountain glaciers.
Glaciers are giant “water reservoirs” and “coolers” greatly influencing the climate and water regime of the Earth (Kotlyakov,
1979). Their state and the changes from this state over time
are an important indicators of global climatic and hydrologicalchanges – past, present and future. Cooling and warming andthe advance and recession of glaciers result in the change of
all the elements of the hydrological cycle: precipitation, runoff
and evaporation, and the volume of water stored on land and in
the ocean. During glaciation a large amount of water becomeslocked up as snow and ice on the land. As a result the volume
of runoff decreases, the World Ocean level falls by tens of metres, uncovering extensive areas of the continental shelves. With
the decline of glaciation, river flow increases, the volume of water in the ocean becomes larger, the level rises and the land area
diminishes.

UNDERGROUND ICE
22.5

3

13 980 000

21 600 000

Areas of permafrost extend over northeast Europe and the northand northeastern parts of Asia, including the Arctic islands;
they cover northern Canada and the fringes of Greenland and15

THE HYDROSPHERE

Antarctica, as well as higher parts of South America. The total
area of permafrost is about 21 million km2 , some 14% of the landarea. In the Southern Hemisphere (Antarctica, South America)
permafrost covers about 1 million km2 . The depth of permafrost
ranges from 400 to 650 m. Underground ice within this range isfound as vein formations and strata. The water stored as underground ice can be estimated only approximately due to lack ofdata and few studies (Grave, 1968) but the most likely figure is
300 thousand km3 (Korzun, 1974b). In the permafrost areas 150–
200 km3 of water occurs in the form of river ice.
The annual snowfall over the Earth is about 1.7 × 1013 tonnes,
and this snow covers an area of between 100 and 126 million km2 .
The distribution of snow varies considerably from year to year
depending on climatic conditions.

Table 1.10. Natural ground water resources in the upper layer ofthe Earth’s crust by hydrodynamic zones

Continent

Zonea

Ground water
resources,
km3 × 106

Europe

1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3

0.2
0.3
1.1
1.3
2.1
4.4
1.0
1.5
3.0
0.7
1.2
2.4
0.3
0.9
1.8
0.1
0.2
0.9

Asia

AfricaNorth America
UNDERGROUND WATER

The volume of gravitational water contained in the pores, fissuresand fractures of the water-saturated strata of the Earth’s crust represents the natural storage of water underground. The geographical distribution of ground water is closely related to the geologicalstructure of the Earth’s crust. It also depends considerably on the
climatic factors: precipitation, condensation and evaporation, andparticularly on the infiltration. Since runoff also depends on thesefactors, there is a strong relationship between ground water andrunoff: ground water draining to rivers are included in the volume
of runoff, being its most stable contribution to the hydrograph,
especially during dry periods and drought.
The reliable estimation of ground water storage is very difficult(Garmonov et al., 1974). The water content of water-bearing
strata can be obtained approximately by multiplying the volume
of water-bearing table by a water loss factor and effective
porosity. The natural storage of ground water is determined down
to the absolute depth of 2000 m – the depth of the isobath whichindicates approximately the distribution of the Earth’s continental
crust.
Three zones of ground water movement can be distinguishedvertically:
1.

2.

A zone of active water exchange is located above the local
base level and is highly dynamic. Movement of water in thiszone increases with height above the base level. Here thecharacter of the water is most closely related to the nature of
the overlying soil and to the rock strata containing them andalso to climatic factors. The effective porosity of this zone isabout 15%.
A zone of less active water exchange is located below thisfirst zone down to sea level. This zone is situated below local base levels and the water here is only affected by large
rivers which may have deep channels. Drainage of groundwater in this zone is also related to basins and depressions.

South America

Australia andOceaniaa

Total resources ofground water,
km3 × 106
1.6

7.8

5.5

4.3

3.0

1.2

For explanation of zones see text.

3.

Where these lie under the sea the discharge of water from thiszone occurs into the sea. Less movement provides for higher
mineralization of ground waters, however here they are basically fresh or weakly mineralized. The nature of the waters
in this zone is determined by the occurrence of aquifers andaquicludes and their juxtaposition in the form of depressions,troughs, synclines and monoclines forming artesian basins.
The effective porosity of this zone is 12%.
A third zone lies in the crust from sea level to the absolutedepth – 2000 m. The waters of the upper part of this zone
are only influenced by the biggest rivers at depth, and bylarge-scale features such as depressions in the relief of land
and the ocean. In the upper part of this zone water is fresh or
weakly mineralized, with saline water and brines below. The
effective porosity is 5%.

The mean altitude of each continent was used for calculating thetotal volume of ground water stored in the Earth’s crust (Korzun,
1974b). The total storage of ground water to the 2000 m level in the
Earth’s crust was estimated to be 23.4 million km3 (Table 1.10).
With 3.6 million km3 in the first zone, 6.2 million km3 in thesecond and 13.6 million km3 in the third, rivers are fed mainly
from water stored in the first zone.

16

THE EARTH AND ITS PHYSICAL FEATURES

Table 1.11. Water resources in the principal lakes of the Earth
Numberof lakes

Total area,
km2 × 103

EuropeAsia
AfricaNorth America
South America
Australia andOceania

34
43
21
30
6
11

Total

145

Continent

Water resources, km3
Fresh

Salt

430.4
209.9
196.8
392.9
27.8
41.7

2 027
27 78230 00025 623913
154

78 000
3 165
–
19
2
174

1300

86 50081 360

Table 1.12. Area of bog over the EarthContinent
Eurasia
AfricaNorth America
South America
Australia and Oceania

Bog area, km2 × 103
925
341
180
1232
4

Table 1.13. Water volume in river channels of
the EarthContinent
EuropeAsia
AfricaNorth America
South America
Australia and Oceania

Water volume inriver channels, km3
80
565
195
250
1000
25

LAKES AND RESERVOIRSThere are 145 large lakes across the globe with an area of
100 km2 and holding 168 thousand km3 of water (Korzun, 1974b)(Table 1.11). This is 95% of the total volume of all the world’s
lakes, giving a total volume of lake water of 176.4 thousand km3 .
Of this total 91 thousand km3 is fresh water, and 85.4 thousand km3
is salt. The hydrology of about 40% of the world’s large lakes has
not been studied and their volumes are estimated approximately.

Some studies (L’vovich, 1986; Wallace, 1996) exaggerated estimates of the water stored in lakes and these vary from 200 000 km3
to 278 000 km3 . The hydrosphere includes water held in reservoirs.
Their total volume exceeds 6000 km3 and they regulate about 15%of the Earth’s total runoff.

WATER STORED IN SWAMPS, CHANNEL NETWORKS,
SOIL, LIVING ORGANISMS, PLANTS
AND THE ATMOSPHERE

Swamps and bogs are widespread across the Earth with a total
area of approximately 2.7 million km2 or about 2% of the landarea. The most swampy continent is South America (Table 1.12).
The total volume of water in the world’s swamps and bogs isestimated to be about 11 470 km3 (Korzun, 1974b). This value
has been obtained on the assumption that the mean thickness ofthe peat bogs is 4.5 m, their volume is 12 070 km3 , and that they
are 95% water.
The hydrosphere also includes the water stored in the river channel network. The total volume of this water – 2120 km3 – wasestimated by the State Hydrological Institute (Korzun, 1974b) taking into account the volume of runoff and the lengths of the mainrivers and their tributaries (Table 1.13). According to L’vovich(1986) this volume is 1200 km3 . In spite of the very small volume of water in the river channels, it is this water which iscontinuously renewed and which is most important for humanuse.
The soil moisture is an integral part of the hydrosphere. Thiswater occurs mainly in the top 2 metres of the soil. The total volume of soil moisture is estimated to be approximately
16 500 km3 (Korzun, 1974b). This figure assumes that soil moisture is 10% of the 2-m layer, and that the area of soil containing moisture covers 55% of the land area or 82 million km2 .
L’vovich (1986) estimated the total volume of soil moisture to
be 83 thousand km3 ; however he did not state the method used toestimate it.
Biological water (the water included in living organisms suchas plants and animals) is an active link in the hydrologic cycle.
Part of the water that evaporates from the land and enters into theatmosphere is due to transpiration of soil moisture by vegetation.
Alpatjyev (1969) gives the volume of living matter in the biosphereas 1.4 × 1012 tonnes. The water content of living matter is about
80% (Derpgolts, 1971), i.e. 1.12 × 1012 tonnes or approximately
1120 km3 .
The water contained in the atmosphere, as water vapour, water
drops and ice crystals, is an important part in the hydrosphere,
possibly the most active part. The total volume of moisture in
the atmosphere, according to the different estimates (Korzun,
1974b; L’vovich, 1986; Wallace, 1996), varies from 12 900 km3
to 14 000 km3 .

17THE HYDROSPHERE

1.2.3 Global water exchange in the hydrosphere – thehydrological cycle
The waters of the hydrosphere are in constant, usually cyclic, motion under the effects of solar radiation, the energy released fromthe Earth’s interior and gravitational forces. Due to geologicalprocesses about 1 km3 of water a year is released from the mantle
through degasification and this rises gradually to the Earth’s surface. As a result of convection in the mantle, part of this mattercan emerge through breaks in ocean rift zones related to oceanic
ridges (Monin, 1977). The global process of water exchange provides some stability in the distribution of waters between the land,
the oceans and the atmosphere. This equilibrium is relative andcan change in time, and these changes can lead to corresponding
changes in hydrological and climatic conditions.
Water evaporating from the surface of reservoirs, soil and vegetation enters into the atmosphere as water vapour where it isdissipated upwards by turbulent diffusion and is transported byair currents from one place to another. With a temperature decrease, water vapour is condensed, transforming it to a liquid or
solid. During rainfall from clouds, part of the water returns to
the Earth’s surface (inland cycle), and part of it returns to reservoirs in the form of runoff. Some precipitation can fall into theocean.
Water evaporated from the surface of the oceans and seas mostly(90%) falls back into the sea, short-circuiting the cycle. A smaller
part of it (10%) participates in the major cycle, being transported
by atmospheric circulation to the land where, as rainfall, it canbe involved in a number of smaller versions of the completehydrological cycle when surface and ground water and ice
drainage reaches the World Ocean, closing the complete cycle.
Part of the water is combined and decomposed by plants.
Part of the water contained by the Earth is in chemical compounds, such as crystal hydrate, sorbate and many other forms
which are found in porous deposits in the Earth’s crust. This chemically combined water can be removed from the total water exchange for thousands of years. The crustal rocks lose water during
the process of metamorphization and subduction under the effects
of high pressure and high temperature. This water rises throughrock pores and appears on the Earth’s surface (Vinogradov,1973).
The global hydrological cycle is not a closed system. Solar energy and energy from space, together with cosmic dust, meteorites
and meteors, arrive from space. The Earth in its turn gives backpart of its energy to space and dissipates hydrogen and helium
to it (Alpatjyev, 1983; Kulp, 1951). This exchange of matter andenergy brings about 0.01 km3 of water per year (Derpgolts, 1971;
Alpatjyev, 1969) from space to the Earth. At the same time partof the hydrosphere is lost due to the dissipation of light gases, andtheir escape beyond the limits of the Earth’s gravitational field,

Table 1.14. Periods of renewal of water resources on
the Earth
Water of hydrosphere
World Ocean
Ground water
Polar ice
Mountain glaciers
Ground ice of the permafrost zone
Lakes
Bogs
Soil moisture
Channel networks
Atmospheric moisture
Biological water

Period of renewal
2 500 years
1 400 years
9 700 years
1 600 years
10 000 years
17 years
5 years
1 year16 days
8 daysseveral hours

amounting to about 0.1 km3 per year (from 0.03 to 0.27 km3 :Yuri, 1959; Pavlov, 1977; Alpatjyev, 1983).
Every year human influences grow and cause more and morechanges to natural processes, including the hydrological cycle.
These changes bring about alterations to the water balance and towater resources and their availability. The rapid growth of population, the development of industrial production and the rise of
agriculture have resulted in the increased use of water, reachinga global total of about 4 thousand km3 per year (Shiklomanov,1997) by 1990. Some 80% of this water is used for agriculture,primarily for irrigation, and this causes more evaporation and an
intensification of the hydrological cycle.
Human activities have also changed the character of groundwater. Although there are some examples of artificial recharge ofaquifers, more often the water table has been lowered to provide
water for drinking. Every year up to 20 thousand km3 of groundwater is abstracted (Plotnikov, 1976), which results generally inthe reduction of aquifer storage and the lowering of ground waterlevels, and in some cases in land subsidence.
The construction of reservoirs has led to the slowing down of the
movement of river waters (Kalinin, 1974). Slowing the movementof water can influence its quality particularly by the accumulationof pollutants. Because the World Ocean water is contaminated byoil products, this leads to the reduction of evaporation from thewater surface by about 10% (Duvanin, 1981) and this contributes
to the reduction in the rate of exchange of water between the ocean
and the land surface.
Of course water in the hydrosphere is connected by the hydrological cycle; however the rates of movement and residence times
are very different for water in its different states (Table 1.14).
Table 1.14 shows that biological waters included in plants andliving organisms are renewed most rapidly – perhaps over a period

18
of a few hours. Plants transpire this water. Atmospheric water,which forms due to evaporation from any water surface, is renewed on average over 8 days. Water stored in the channel network is also renewed on average over a period of 16 days. The
soil water is renewed over a period of a year and is spent mainlyfor evaporation and partly on runoff. Water stored in swamps has
a 5-year residence time.
Most lake water is renewed on average over a period of 17 years.
However different lakes have different renewal times. For example, for Lake Baikal this time is 380 years. All other types

THE EARTH AND ITS PHYSICAL FEATURES

of natural waters (glaciers, ground waters, ocean waters etc.)
are renewed more slowly, possibly over periods of thousandsand even tens of thousands of years. The largest period is forthe ice in the tundra and in Antarctica, which may be renewed
only over several hundreds of thousands of years (Kotlyakov,
1984).
The time data presented here for the exchange of natural water inthe global hydrological cycle (Korzun, 1974b; L’vovich, 1986) arevery approximate and typical of the lower limits of the exchange
process (Kalinin, 1972).