REPORT TO
NATIONAL COUNCIL FOR SOVIET AND EAST EUROPEAN RESEARC H
TITLE : Desiccation of the Aral Sea : A Wate r
Management Disaster in the USS R
AUTHOR :
CONTRACTOR :
Philip P . Micklin
Western Michigan Universit y
PRINCIPAL INVESTIGATOR : Philip P . Micklin
COUNCIL CONTRACT NUMBER : 802-9
DATE : March,198
The work leading to this report was supported by funds provided b y
the National Council for Soviet and East European Research . Th e
analysis and interpretations contained in the report are those o f
the author .
NOTE
This report is an incidental product of the Council-funded researc h
contract identified on the face page . It is not the Final Report unde r
that contract, which will be distributed separately at a later date .
A Water Management Disaster in the USSR : th e
Desiccation of the Aral Se a
A paper (poster) presented at the Annual Meeting of the America n
Association for the Advancement of Science, Boston, 11-15 February 1988 .
by
Philip P . Mickli n
Dept . of Geograph y
Western Michigan Universit y
Kalamazoo, Michigan 4900 8
ABSTRACT
The Aral Sea, a saline lake, located among the deserts of th e
southern USSR is rapidly disappearing . In 1960, it was th e
world's fourth largest lake (area = 68,000 km 2 ) . By 1987, th e
sea's level had dropped nearly 13 meters with an accompanyin g
decrease in surface area and volume of around 40% and 64% ,
respectively . The sea's shrinkage owes to greatly reduced inflo w
from its major influents, the Syrdar'ya and Amudar'ya rivers .
Widespread irrigation is the fundamental factor reducing rive r
flow . Desiccation has caused severe environmental problems fo r
the sea and a large adjacent zone, including fisheries destruction, desertification of the deltas of the Amudar'ya and Syrdar'ya, and the blowing of salt from the dried bottom of the se a
hundreds of kilometers inland . These problems are growing worse .
Unless radical corrective measures are taken, the sea will dry t o
a residual brine lake in the next century . Local water resource s
and water management measures may prove inadequate to "save" th e
sea and its preservation may require "resurrection" and implementation of the recently cancelled Siberian water transfe r
project .
ACKNOWLEDGEMENTS
Work leading to this paper was supported from funds provided b y
the National Council for Soviet and East European Research ,
which, however, is not responsible for its content or findings ,
the National Academy of Sciences which funded a three mont h
research exchange in the USSR during fall 1987, and the Luci a
Harrison Fund of the Department of Geography, Western Michiga n
Universty . The author also expresses thanks to the Institute o f
Water Problems, Institute of Geography, and Desert Institute o f
the Soviet Academy of Sciences for providing data and othe r
information which aided in this research . Mr . Brian Fogle (re search assistant, Dept . of Geography, Western Michigan University) provided assistance in the preparation of the figures .
1
The Aral Sea is a huge, shallow, saline waterbody locate d
among the deserts of the southern USSR [Figures 1,2,3,4] . As a
terminal lake (i .e . one having no outlet) its level is basicall y
determined by the balance between surface inflow and precipitation (on the water surface) on the one hand and evaporatio n
on the other . There is also a small net inflow of groundwater ;
its magnitude is unknown but believed minor . Scientists estimate the Aral's age at around 10,000 years . Over this period ,
its level has fluctuated at least 20 meters in response t o
climatic variation and the actions of man (including ancient an d
medieval societies who purposely and inadvertently caused larg e
alterations in inflow) . The sea was relatively stable betwee n
1910 and 1960, when the range of level change was less than on e
meter . However, over the past 28 years the sea's surface ha s
dropped precipitously . In 1960, sea level was 53 .41 meters ,
area 68,000 km2 , volume nearly 1090 km 3 , average depth 1 6
meters, and average salinity around 10 g/l . In area, the Ara l
was the world's fourth largest lake . By 1985, sea level ha d
fallen 11 .46 meters, area decreased to 44,400 km 2 , volume
diminished to 438 km 3 , average depth dropped to 10 meters, an d
salinity risen to over 22 g/l . By early 1987, the level dro p
was between 12 and 13 meters . This is the most severe (an d
certainly most rapid) recession of the sea in many centuries .
It has had profound adverse ecological, economic, and socia l
consequences for the region adjacent to the sea which wil l
become worse as the sea continues to dry .
CHANGES IN THE ARAL
SEA WATER
BALANC E
The cause of this ecological disaster is the substantia l
reduction of inflow from the Syrdar'ya and Amudar'ya rivers, th e
only tributaries to this waterbody, which has shifted the sea' s
water balance heavily to the negative side . As can be seen from
2
Figure 5 and Table 1, the trend of river discharge has bee n
steadily downward since 1960 (with the exception of the ver y
heavy flow year of 1969), reaching insignificant levels by th e
1980s . The gap between the gain and loss sides of the water balance has steadily increased and, accordingly, the sea' s
A
level, area, and volume diminished at an increasing rate .
desiccating terminal lake is primarily a negative feedbac k
system : its shrinking area decreases evaporative losses, al though there is some positive feedback since as area decrease s
the thickness of the evaporative layer increases slightly .
Hence, eventually (assuming some level of surface and ground water inflow), the Aral should stabilize . However, as of th e
mid-1980s, the difference between inflow and net or visibl e
evaporation (i .e . surficial evaporation minus surficial precipi tation) was so large that, assuming a continuation of lo w
inflow, the sea will continue to shrink for decades (Figure 5) .
The causes of the decreased inflow are primarily anthropogenic . An abnormal number of dry years (in the mid-1970s an d
again in the early 1980s) has played a role but the dominan t
factor has been large consumptive withdrawals from the Amudar'y a
and Syrdar'ya and their tributaries, overwhelmingly for irrigation . Average annual river flow in the zones of formation o f
these rivers (high mountains to the southeast of the Aral Sea )
is estimated at 110 km', although under "natural" condition s
only about one half of this would be expected to reach the Ara l
because of losses to evaporation, transpiration and filtratio n
as these rivers cross the deserts and flow through their deltas .
Irrigation has been practiced in the lower reaches of th e
Amudar'ya and Syrdar'ya for millenia . At the turn of th e
current century, it encompassed 2 .3-2 .5 million ha in the Ara l
Sea Basin and grew to 3 .5 million ha by 1960 . This level o f
irrigation, study show, did not measurably reduce inflow to th e
Aral because losses to consumptive withdrawals were compensate d
by reduced evaporation, transpiration, and filtration in the
3
deltas owing to lowered spring floods which diminished wate r
levels, the area of deltaic lakes, and the expanse of phreatophytes . Since 1960, the area of irrigation in the Aral Se a
Basin has grown to near 8 million ha . Total withdrawals for al l
purposes reached 160 km 2 by the early 1980s with consumptiv e
withdrawals (those not returned directly to rivers) around 10 5
km 2 (nearly all the latter resulted from irrigation) . However ,
the compensatory factors that had acted to balance consumptiv e
withdrawals prior to 1960 have been exhausted and overwhelmed b y
the scale of irrigation expansion of the past 28 years . Also ,
the irrigation of huge new areas such as the Golodnaya (Hungry )
steppe along the Syrday'ya which required huge volumes of wate r
to fill pore spaces, the creation of giant reservoirs with larg e
evaporative surfaces, and the diversion of water from th e
Amudar'ya (over 14 km' in 1986) 1100 km westward along the Kara Kum Canal, which is completely lost to the Aral Sea, hav e
magnified the reducing impact of irrigation expansion on rive r
discharge to the Aral Sea .
CONSEQUENCES OF THE ARAL SEA'S RECESSIO N
The drying of the Aral Sea has had major physical, ecological, and social-economic consequences The most important o f
these are discussed below .
Between 1960 an d
I . Changes in the Sea's Physical Parameters .
1985, sea level fell by 11 .46 meters, area shrank by 23,600 k m2
(35%), volume diminished by 652 km' (60%), and average salinit y
more than doubled from 10 to 24 grams/liter (Figure 6) . I f
surface inflow to the Aral remains at the very low levels o f
recent years (it averaged only 5 .2 km3/yr from 1981-85), the se a
will continue to shrink well into the next century, with th e
area stabilizing (assuming a residual inflow of irrigatio n
drainage water and groundwater totalling around 10 km 3 ) at
4
12,000 k m 2 - 8% of its size in 1960 - whereas salinity will ris e
to 140 g/l .
II. Exposure of Salt Covered Bottom .
The quantity of sal t
contained in the Aral before the current recession has bee n
estimated at 10 billion tons °
As the sea has retreated, enormous quantities of salt have been deposited as a loose layer o n
the exposed bottom which by 1987 was more than 24,000 km 2
(Figure 7) . The dominant compounds in this layer are NaCl ,
Na2SO4, CaSO4, MgSO4, Mg(HCOJ)2, and Ca(HCO3)2 . The larges t
amounts of salt have accumulated along the southern, eastern ,
and northeastern coast of the Aral where a 15 to 75 km wid e
stripe has been exposed . These salt covered areas are resistan t
to natural and artificial revegetation and also are hearths fo r
the formation of salt/dust storms .
III. Salt/dust Storms Arising from the Dried bottom . One of th e
most serious problems connected with the drying of the Aral Se a
is the blowing of salt and dust from its dried bottom . The mos t
serious storms arise from the exposed bottom of the sea' s
northeastern coast and lift material up to 2 km into th e
atmosphere and carry it for up to 500 km (Figure 7) . The larg e
storms are thought to have started and were first spotted o n
space imagery in 1975 . From 1975-81, 29 large storms wer e
confirmed by Soviet scientists from analysis of Meteor
(a hig h
resolution weather satellite) images . Up to 10 major storm s
have occurred in one year . Sixty percent of the observed storm s
moved in a southwest direction which carried them over the delt a
of the Amudar'ya River, a region with major ecological an d
agricultural importance . Twenty five percent of storms travel led westward and passed over the Ust-Yurt plateau which is use d
for livestock pasturing . It has been estimated that 43 millio n
tons of salt annually are carried from the sea's dried botto m
into adjacent areas and deposited as aerosols by rain and dew
5
over 150,000-200,000 km 2 . These salts, particularly sodium bicarbonate, sodium chloride, and sodium sulfate, are toxic t o
plants, especially during flowering . In spite of the expecte d
increase in the area of former bottom, the export of salt i s
predicted to slightly diminish to 39 million tons/yr by 2000 a s
a result of the exhaustion of deflatable salt, the leaching o f
salt into deeper layers, and through the process of diagensis o f
the older surface salts .
As the sea ha s
IV . Loss of the Sea's Biological Productivity .
shallowed, shrunk, and salinized, biological productivity ha s
steeply declined and 20 varieties of native fish species hav e
nearly disappeared (Figure 8-A) . By the early 1980s, biomas s
and phytoplankton had decreased 3 to 5 times compared to thei r
pre-1960s levels whereas the haul of commercial fishes (48,00 0
metric tons in 1957) declined to zero . As salinity continues t o
rise, even ocean species that have been introduced, such a s
flounder, will be unable to survive . The large fish cannery a t
Muynak, which was formerly on the Amudar'ya delta's shorelin e
with the Aral but is now tens of kilometers inland, has bee n
forced to import fish for processing from distant regions ,
including the Atlantic . With the end to commercial fishing, a
mainstay of the local economy, there has been an exodus o f
population from Muynak and many former fishing villages hav e
been abandoned . Residual commercial fishing continues in deltaic lakes (e .g . Sudoch'ye in the Amudar'ya Delta) and in th e
two largest irrigation drainage water lakes that have forme d
(Sarykamysh and Aydarkul') which are biologically rich . However, the deltaic lakes are drying whereas levels of pesticide s
and herbicides (from cotton field runoff) in fish caught i n
Sarykamysh and Aydarkul' are dangerously high, prompting a hal t
to commercial fishing in the former lake in 1987 .
V.
Deterioration of Deltaic Ecosystems .
The Aral's recession
6
along with the greatly diminished flow of the Syrdar'ya an d
Amudar'ya rivers in their lower reaches has had devastatin g
effects on their deltas . Distributary and even main channel s
have dried or become deeply entrenched, spring inundation o f
floodplains has ceased and floodplain lakes have shrunk or disappeared (Figure 8-B) . Native vegetational complexes, mos t
importantly Tugay forests (composed of dense, often impassabl e
stands of water-loving trees such as popular, willow, tamarisk ,
ash, and buckthorn mixed with shrubs and tall grasses whic h
fringe deltaic arms and channels to a depth of several kilo meters) have degraded and disappeared (Figure 8-C) . Groun d
water levels have dropped meters making it more difficult o r
impossible for hydrophytes and phreatophytes to obtain moisture .
Deltaic desiccation has promoted the rapid expansion of desertification . The rich and diverse fauna of the delta whic h
includes wild boar, deer, jackel, many kinds of birds, and unti l
recent decades even a few tiger) have also greatly suffere d
through alteration and disappearance of their natural habitats .
The most serious effects have occurred in the huge Amudar'y a
Delta . Here by 1980 more than 50 lakes with an aggregate are a
of 1000 k m 2 had dried, groundwater levels had declined from 3 t o
8 meters, and tugay forests which covered 1,300 k m2 in 1961 ha d
decreased to around 50 km 2 .
The Aral influence s
VI . Climatic Changes Around the Aral Sea .
both temperature and moisture conditions in an adjacent strip e
estimated to be 50-80 km wide on its north, east and west side s
and 200-300 km to the south and southwest . With the sea' s
contraction these climatic influences have substantially diminished leading to warmer summers, cooler winters, later sprin g
and earlier fall frosts, a shortened growing season, lowere d
humidity, and an overall trend toward greater continentalit y
around the waterbody . The greatest changes have occurred in th e
Amudar'ya Delta . For example, at Kungrad, now located about 100
7
km south of the Aral, comparison of the period 1935-60 wit h
1960-81, indicates that relative humidity diminished 1 .4 fold ,
the average May temperature rose 3-3 .2°C and that the averag e
October temperature decreased 0 .7-1 .5° . There is fear that th e
growing season in the Karakalpak Autonomous Republic, located t o
the sea's immediate south, may shorten sufficiently to adversel y
affect the raising of cotton .
VI . Declining Groundwater Levels Around the Aral
Sea .
The dro p
of the Aral Sea has been accompanied by a decline of groundwate r
levels for a considerable distance from its shore . Sovie t
scientists have estimated that a 10 meter drop of the Ara l
(reached in 1984) would lower the level of ground and artesia n
water by 5-9 meters in a 30 to 40 km coastal stripe and have a
depressing influence from 60-100 km inland . A 15 meter se a
level drop (likely by the mid 1990s) could reduce groundwate r
levels by 7-12 meters in the coastal zone and affect the water
table 80-170 km away from the sea . Declining groundwater level s
have had significant adverse effects outside the Amudar'ya an d
Syrdar'ya deltas, drying wells and springs, degrading natura l
plant communities, pastures and hayfields and generally contributing to the spread of desertification .
There are n o
VI . Estimates of Losses from the Aral's Recession .
accurate monetary estimates of the damage caused by the Aral' s
drop . However, Soviet scientists and economists have attempte d
to place some preliminary "ballpark" measures on the majo r
negative changes that are more amenable to economic determination . A 1979 study [K .I . Lapin and E .D . Rakhimov, "An
Attempt to Estimate the Social-economic Consequences of th e
Desiccation of the Aral Sea,"
Problems of
Desert Development ,
.
(in
Russian)]
concluded
that aggregat e
No . 2 (1979), p . 90
.4
to 5 .7 billio n
damages within the Uzbek Republic totalled 5
.
A
more
recent
evaluation
[Gerasimov
et
al
., "The Aral
rubles
8
Sea Problem and the Anthropogenic
Desertification o f the Ara l
Region," Problems of Desert Development, No . 2 (1983) , p . 29 (i n
Russian)]
estimated that annual damages only in the lowe r
reaches of the Amudar'ya (basically the delta region) were 92 . 6
million rubles with the following distribution of losses (i n
millions of rubles) : fisheries (28 .9), hunting and trappin g
(11 .6), agriculture (39 .1), living and working conditions (6) ,
and river and sea transport (7) .
THE FATE OF THE ARAL
What does the future hold for the Aral Sea? Assuming a
continuation of the low inflows characteristic of recent year s
and lack of implementation of ameliorative measures, the se a
will continue to shrink and sometime in the next centur y
stabilize as a lifeless, residual brine lake . More water coul d
be supplied to the sea if consumptive irrigation withdrawal s
were reduced and, thereby, river flow increased . However, irrigation continues to grow here, although plans for future expansion have been scaled back under the Gorbachev regime . There i s
a national campaign underway to improve water use in irrigatio n
through such measures as reconstruction of old, inefficien t
irrigation systems, automation and telemechanization of wate r
delivery facilities, and "programming" of harvests (involvin g
the use of simulation-optimization models to minimize inputs an d
maximize outputs under a set of production objectives and constraints) . Since irrigation system efficiency (ratio of wate r
withdrawn at the headworks to the amount arriving at the field )
is low in the Aral Sea Basin (50-60%), raising it to 75-80% ,
considered a reasonable goal, could save considerable water .
Aside from being an expensive and time consuming process, mos t
of this "freed" water will likely be needed to irrigate ne w
lands to produce more food for the region's very rapidly growin g
population as well as meeting expanding municipal and industria l
9
water needs .
A more realistic means of providing more water to the Ara l
is to channel irrigation drainage water to it . Around 34 km3 o f
drainage water are estimated to have been generated in the Ara l
Basin in the early 1980s . About 21 km3 of this already return s
to rivers leaving 13 km' that evaporates from drainage wate r
lakes or the desert . Some of this could be carried by pipe o r
special canal to the Aral (by one estimate 10-12 km3/yr) .
However, the drainage water is saline (averaging about 3 g/l
)
and pesticide and herbicide laden whereas the cost of constructing the special conveyance facilities (reportedly underway )
will be high . Additionally, the two largest drainage wate r
lakes, Aydarkul' and Sarykamysh (see Figures 2 and 3 for location), with areas in excess of 2000 km 2 each, and which hav e
developed wildlife, fishery, and recreational value, would dry .
It must be noted that the program to improve irrigation efficiency will significantly reduce the amount of drainage water .
Even assuming that 10-12 km' of drainage water could b e
delivered to the sea, this water plus some groundwater inflo w
(perhaps 3-4 k m3 ) would likely constitute the total discharge t o
the Aral . Without further ameliorative measures, this woul d
only support a sea of around 19,000 k m2 whose salinity would b e
very high . In light of this reality, mitigative approache s
have been suggested to "save" the Aral as an ecologically viabl e
but greatly shrunken waterbody and to reduce the adverse impact s
of its recession . A number of schemes have been proposed t o
divide the sea with dikes, preserving low salinity conditions i n
limited parts of it and allowing the remainder to dry or becom e
a salt accumulator . Several of these are shown on Figure 9 .
Discharge to the waterbody has dropped so rapidly and its are a
shrunken so greatly that designs 9-A, 9-B, and 9-C are "obsolete" since it is unlikely there will be sufficient inflow t o
implement them . Design 9-D is sustainable, particularly if
10
facilities are built to deliver collector drainage water directly to the sea . As part of this plan, the shoreline of th e
"active" portion of the sea would be steepened by dredges s o
that seasonal fluctuations in surface area leading to sal t
deposition on the shore would be minimized . Regardless of wha t
mitigative scheme is implemented or even if no efforts are mad e
to preserve the sea, measures must be instituted to stabiliz e
the salt covered former bottom and to greatly reduce the blowin g
of salt and dust from it . Field experiments are underway t o
develop means (e .g . phyto-reclamation, forest shelterbelts ,
chemical binders) that are feasible to accomplish this goal .
One means of improving the Aral's water balance situatio n
would be to supplement it via the addition of water importe d
from more humid regions . A project that would have done thi s
was formulated in the 1970s and early 1980s by the Nationa l
Water Management Design and Scientific Research Institut e
(Soyuzgiprovodkhoz), a subagency of the Ministry of Reclamatio n
and Water Management . The main purpose of this plan was t o
supply more water for irrigation, but directly and indirectly i t
would have provided more water to the Aral . The scheme wa s
enthusiastically supported by Central Asian Party and govern mental officials . Water was to be diverted into the regio n
from the Ob' and Irtysh rivers situated to the north in Wester n
Siberia . Low dams, pumping stations, and a huge canal (popularly named "Sibaral" - Siberian to the Aral Sea Canal) were t o
transport water over a distance of 2500 kilometers as far as th e
Amudar'ya River (Figure 2) . The first phase of the scheme, tha t
would have transferred 27 km3/yr, was in the final design phas e
by 1985 and, it appeared, could be under construction by th e
late 1980s or early 1990s .
After Gorbachev assumed leadership in 1985, the Siberian a s
well as European transfer protects' fortunes waned rapidly . He
and his advisors saw the schemes as a poor use of scarce
11
resources and contended that less costly, more effective mean s
of solving southern water problems were available . The transfers had been periodically attacked during the 1970's and earl y
1980's as unnecessary and ecologically damaging by scientist s
and writers from areas of proposed water export who believe d
they would severely damage their regions . But public doubt s
about the projects had been officially discouraged for severa l
years as they moved closer to implementation . By summer 1985 ,
public criticism was again permissible and probably officiall y
encouraged . Beginning in the fall of that same year, th e
schemes and those who were directly or indirectly involved wit h
them were repeatedly (and sometimes viciously) attacked in th e
main popular print media by a group of Russian national writer s
and a number of scientists, including some academicians . Th e
criticism tended toward exaggeration and, frequently, was scien tifically and factually inaccurate . Nevertheless, in a dramatic policy reversal, construction of the initial phase o f
European transfers was dropped from the 12th Five Year Plan a s
was further design work on the Siberian project . In Augus t
1986, a joint decree of the Central Committee of the Communis t
Party of the Soviet Union and the Council of Ministers officall y
ordered a cessation of construction and design work on th e
European and Siberian projects . However, research on the scientific problems associated with water diversions, stressing ecological and economic concerns, is continuing .
In summary, the future of the Aral is not bright . The se a
continues to recede and salinize with a variety of sever e
accompanying ecological problems and economic losses . To b e
sure, scientific study of the "Aral problem" and its amelioration has been a national effort since 1976 under the aegis o f
the State Committee on Science and Technology . Furthermore ,
the decree ordering the cessation of work on diversion project s
directed that a complex program for the development of Central
12
Asia to 2010, considering the demographic, water management, an d
agricultural situation, be formulated and presented to the USS R
Council of Ministers not later than the first quarter of 1987 .
Nevertheless, other than the reported start of construction of a
pipeline to carry some drainage water to the sea, no concret e
actions of any significance are being taken . The Siberia n
diversion project has been cancelled, but its "resurrection" i n
the 1990s if the water management situation in the Aral Se a
Basin continues to worsen, cannot be ruled out . Although part y
and government officials from the republics adjacent to the Ara l
Sea are keeping quiet, the past few years have seen scientists ,
writers, and journalists from this region angrily and sometime s
eloquently pleading in the regional as well as national pres s
for somekind of action to save the Aral, in their view a
national if not world treasure, before it is too late . So fa r
these cries for help have fallen on deaf ears . Indeed, I wa s
told by knowledgeable Soviet scientists during the fall of 198 7
that the sea may already be beyond rescue .
SELECTED REFERENCE S
Azimov, Sarvar, "How to Save the Aral?"
November 26, 1986, p . 11 .
[in Russian] .
Literary Gazette ,
Dukhovnyy V . A . et al ., "The Problem of the Aral Sea and Natur e
Protection Measures," Problems of
Desert Development,
No . 6 ,
[in Russian ]
1984, pp . 3-15 .
Grigor'yev, Al . A ., "Large-scale Changes of the Nature of th e
Aral Region as Determined by Monitoring from Space," Problems o f
Desert Development, No . 1, 1987, pp . 16-22 . [in Russian ]
Yusupov, E ., "How to Stabilize the Aral?"
September 10, 1987, p . 3 .
[in Russian]
Truth of the East ,
Figure 3:
AVHRR IMAGE OF ARAL BASIN
(7/386)
Image resolution is around 1 km . Dark tones indicate water and vegetate d
areas (oases, irrigated lands, deltas and floodplains) . Lighter tone s
indicate sandy and scrub desert . The lightest areas are playa
lake bed s
and salt flats . Satellite : NOAA-9
.
Spectral Range :
.58- .68 . Source :
National Environmental Satellite, Data, and Information Service .
ure 4o
ARAL SE A
lira I'
k
Small Ara/ Sea
Sgr Dar' go R .
Barsa-Ke
I' me s
ISland
Yozhrozhden Ly e
Is
L.)
o
lan d
Easter n
Ba 5 i n
Muynak
~0
6
14 no
Qa p~p
°
4
L.
Sudoc
r`
h' ye
5
Rdudar '
0
yo R .
1
6(
kn,
a
b
Sea LeeI S
53m
51m
48 m
43m
(1960 )
(1971 )
(1976 )
(1984)
Source : Institute of Water Problems, USSR Academy of Sciences
(based on data compiled by A . Ye . Asarin and V . N . Bortnik .)
(*) measured above Baltic Sea leve l
Table 1 . AVERAGE ANNUAL WATER BALANCES FOR THE ARAL SEA
AVG . AREA (sq . km)
GAIN[5]
RIVER DISCHARGE
PRECIPITATION
LOSS
EVAPORATION
AVERAGE NE T
VOLUME CHANGE
1926-60[2]
65,780
cubic
km
63 .4
55 .2
8 .2
64 .1
64 .1
0 .7
mm
963 .5
838 .6
124 .9
973 .5
973 .5
10 .0
1960-70[3]
63,470
cubic
km
51 .2
42 .8
8 .4
63 .3
63 .3
-12 .2
mm
806 .7
674 .0
131 .7
997 .7
997 .7
-191 .9
[1]
1970-85[4 ]
53,66 0
cubi c
km
mm
22 .9
426 . 8
16 .3
304 . 3
6 .6
122 . 6
56 .2
1046 . 6
56 .2
1046 . 6
-33 .3
-619 .7
Source : calculated from data provided by the Institute of Wate r
Problems, USSR Academy of Sciences (based on compilations o f
A . Ye . Asarin and V . N . Bortnik) .
[1] Some figures do not correspond exactly to others because o f
cumulative rounding errors . [2) period of stable leve l
(3l period of moderately rapid decline (4] period of rapid declin e
[5) there is a small net groundwater gain which is usually ignore d
ANNUAL WATER BALANCE EQUATION FOR THE ARAL SEA
Qr+Qu±(P*F)/10° = (E*F)/10°+(dh*F)/10° wher e
Or = annual river inflow in km' ;
Qu = annual net groundwater inflow in km' ;
P = annual precipitation on the sea in millimeters ;
E = annual evaporation from the sea in millimeters ;
F = average annual area in km' ;
dh = net annual sea level change in millimeters .
cure , .
SPACE SHUTTLE PHOTO OF ARAL (8/6/8 5
Looking south . The eastern and northeastern shore stripe of sal tcoverd
former bottom with blowing salt and dust is at left . The Amudar'ya Delta ,
with clear evidence of desertification, and Lake Sarykamysh are in th e
background . The former delta of the Syrdar'ya is in the left foreground .
Shuttle altitude : 178 km . Source : EROS Data Center .
B
A.
Sudak (pike-perch, Lucioperca lucioperca) caught in the Ara l
in 1978 . A large, tasty fish (reaching 4000 grams and 7 5
cm),
sudak are semi-anadromous and require low salinity .
By the early 1980s, this species disappeared from the Ara l
Sea as average salinity rose above 15 g/l .
B . The main channel (Engineernyy
Uzlyak) of the Amudar'ya nea r
its entrance to the Aral in October 1982 . Only 2 km '
reached the sea from both the Amudar'ya and Syrdar'ya i n
this year .
C.
Tugay (floodplain forest-scrub) along the bank of a distributary channel of the Amudar'ya Delta in July 1982 . Th e
area of this vegetation community has greatly decreased a s
the delta has desiccated owing to reduced river flo w
through it and the recession of the Aral Sea .
Source : photographs courteoy of Dr .
M. I .
Novikova ,Instiue
Problems, Academy of Sctences, USSR .
0 Water
LEGEND FOR FIGURE 9
1 - active (freshened and circulating) part of sea ; 2 isolated (salt accumulating) part of sea ; 3 - drie d
part of sea ; 4 - earthen dam ; 5 - spillway ; 6 location and direction of inflow and outflow fo r
active part of se a
A . Separation of northern "small sea" in 1980 and deepe r
western part of sea in 1985 . Average annual physica l
characteristics of active sea : area - 20,000 km 2 ;
volume - 293 km' ; level - 53 m (small sea) and 46 .5 m
(large sea) ; salinity - 5 to 6 g/l by 2050 ; surfac e
inflow - 30 km' ; outflow - 15 km' .
B . Isolation of northern part of sea in 1980 and wester n
part in 2000 . Average annual physcial characteristic s
of active sea : area - 30,000 km 2 ; volume - 285 km 3 ;
level - 46 .6 m ; salinity - 13-15 g/l by 2050 ; surfac e
inflow - 30 km 3 ; outflow - 15 km 3 .
C.
Separation of eastern part of sea from western wit h
canal connecting small northern sea . Average annua l
physical characteristics of active sea : area - 20,00 0
k m 2 ; level - 38 m ; salinity - 12 g/l ; surface inflow 24 .4 km' ; precipitation on sea surface - 2 .5 km' ;
groundwater inflow - 2 km' ; outflow - 10 .3 km' ;
evaporation from sea surface - 18 .6 km' .
D . Separation of central and southern part of eastern sea .
Average annual physical characteristics of active sea :
area - 12,000 km 2 ; level - 38 m ; salinity - 12 g/l ;
minimum surface inflow - 8 .05 km' ; precipitation o n
sea surface - 1 .51 km' ; groundwater inflow - 1 . 6km3
outflow - dependent on inflow above minimum ; evaporation from sea surface - 11 .6 km 3 .