REPORT TONATIONAL COUNCIL FOR SOVIET AND EAST EUROPEAN RESEARC H

TITLE : Desiccation of the Aral Sea : A Water

Management Disaster in the USS R

AUTHOR : Philip P . Micklin

CONTRACTOR : Western Michigan University

PRINCIPAL INVESTIGATOR : Philip P . Micklin

COUNCIL CONTRACT NUMBER : 802-9

DATE : March, 1988

The work leading to this report was supported by funds provided b ythe National Council for Soviet and East European Research . Th eanalysis and interpretations contained in the report are those o fthe author .

NOTE

This report is an incidental product of the Council-funded researc hcontract identified on the face page . It is not the Final Report unde rthat contract, which will be distributed separately at a later date .

A Water Management Disaster in the USSR : th eDesiccation of the Aral Se a

A paper (poster) presented at the Annual Meeting of the America nAssociation for the Advancement of Science, Boston, 11-15 Febru-ary 1988 .

by

Philip P . Mickli nDept . of Geography

Western Michigan Universit yKalamazoo, Michigan 4900 8

ABSTRACT

The Aral Sea, a saline lake, located among the deserts of thesouthern USSR is rapidly disappearing . In 1960, it was theworld's fourth largest lake (area = 68,000 km 2 ) . By 1987, thesea's level had dropped nearly 13 meters with an accompanyingdecrease in surface area and volume of around 40% and 64% ,respectively . The sea's shrinkage owes to greatly reduced inflowfrom its major influents, the Syrdar'ya and Amudar'ya rivers .Widespread irrigation is the fundamental factor reducing rive rflow . Desiccation has caused severe environmental problems forthe sea and a large adjacent zone, including fisheries destruc-tion, desertification of the deltas of the Amudar'ya and Syr-dar'ya, and the blowing of salt from the dried bottom of the se ahundreds of kilometers inland . These problems are growing worse .Unless radical corrective measures are taken, the sea will dry t oa residual brine lake in the next century . Local water resource sand water management measures may prove inadequate to "save" th esea and its preservation may require "resurrection" and imple-mentation of the recently cancelled Siberian water transfe rproject .

ACKNOWLEDGEMENTS

Work leading to this paper was supported from funds provided b ythe 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 monthresearch exchange in the USSR during fall 1987, and the Luci aHarrison Fund of the Department of Geography, Western Michiga nUniversty . The author also expresses thanks to the Institute o fWater Problems, Institute of Geography, and Desert Institute o fthe Soviet Academy of Sciences for providing data and othe rinformation which aided in this research . Mr . Brian Fogle (re -search assistant, Dept . of Geography, Western Michigan Univer-sity) provided assistance in the preparation of the figures .

1

The Aral Sea is a huge, shallow, saline waterbody locate damong the deserts of the southern USSR [Figures 1,2,3,4]. As aterminal lake (i .e . one having no outlet) its level is basicall ydetermined by the balance between surface inflow and precip-itation (on the water surface) on the one hand and evaporatio non the other . There is also a small net inflow of groundwater ;its magnitude is unknown but believed minor . Scientists esti-mate the Aral's age at around 10,000 years . Over this period ,its level has fluctuated at least 20 meters in response t oclimatic variation and the actions of man (including ancient an dmedieval societies who purposely and inadvertently caused larg ealterations in inflow) . The sea was relatively stable between1910 and 1960, when the range of level change was less than on emeter . However, over the past 28 years the sea's surface ha sdropped precipitously . In 1960, sea level was 53 .41 meters ,area 68,000 km2 , volume nearly 1090 km3 , average depth 1 6meters, and average salinity around 10 g/l . In area, the Ara lwas the world's fourth largest lake . By 1985, sea level ha dfallen 11 .46 meters, area decreased to 44,400 km 2 , volumediminished to 438 km 3 , average depth dropped to 10 meters, an dsalinity risen to over 22 g/l . By early 1987, the level dropwas between 12 and 13 meters . This is the most severe (andcertainly most rapid) recession of the sea in many centuries .It has had profound adverse ecological, economic, and socia lconsequences for the region adjacent to the sea which wil lbecome worse as the sea continues to dry .

CHANGES IN THE ARAL SEA WATER BALANCE

The cause of this ecological disaster is the substantia lreduction of inflow from the Syrdar'ya and Amudar'ya rivers, th eonly tributaries to this waterbody, which has shifted the sea' swater balance heavily to the negative side . As can be seen from

2

Figure 5 and Table 1, the trend of river discharge has bee nsteadily downward since 1960 (with the exception of the ver yheavy flow year of 1969), reaching insignificant levels by th e1980s . The gap between the gain and loss sides of the water -balance has steadily increased and, accordingly, the sea' slevel, area, and volume diminished at an increasing rate . Adesiccating terminal lake is primarily a negative feedbac ksystem : its shrinking area decreases evaporative losses, al -though there is some positive feedback since as area decrease sthe 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 themid-1980s, the difference between inflow and net or visibl eevaporation (i .e . surficial evaporation minus surficial precipi -tation) was so large that, assuming a continuation of lo winflow, the sea will continue to shrink for decades (Figure 5) .

The causes of the decreased inflow are primarily anthro-pogenic . An abnormal number of dry years (in the mid-1970s andagain in the early 1980s) has played a role but the dominan tfactor has been large consumptive withdrawals from the Amudar'y aand Syrdar'ya and their tributaries, overwhelmingly for irri-gation . Average annual river flow in the zones of formation o fthese rivers (high mountains to the southeast of the Aral Sea )is estimated at 110 km', although under "natural" condition sonly about one half of this would be expected to reach the Ara lbecause of losses to evaporation, transpiration and filtratio nas these rivers cross the deserts and flow through their deltas .Irrigation has been practiced in the lower reaches of theAmudar'ya and Syrdar'ya for millenia . At the turn of th ecurrent century, it encompassed 2 .3-2 .5 million ha in the Ara lSea Basin and grew to 3 .5 million ha by 1960 . This level o firrigation, study show, did not measurably reduce inflow to th eAral because losses to consumptive withdrawals were compensate dby reduced evaporation, transpiration, and filtration in the

3

deltas owing to lowered spring floods which diminished wate rlevels, the area of deltaic lakes, and the expanse of phreato-phytes . Since 1960, the area of irrigation in the Aral Se aBasin has grown to near 8 million ha . Total withdrawals for al lpurposes reached 160 km 2 by the early 1980s with consumptiv ewithdrawals (those not returned directly to rivers) around 10 5km 2 (nearly all the latter resulted from irrigation) . However ,the compensatory factors that had acted to balance consumptiv ewithdrawals prior to 1960 have been exhausted and overwhelmed b ythe 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 rto fill pore spaces, the creation of giant reservoirs with larg eevaporative surfaces, and the diversion of water from th eAmudar'ya (over 14 km' in 1986) 1100 km westward along the Kara -Kum Canal, which is completely lost to the Aral Sea, hav emagnified the reducing impact of irrigation expansion on rive rdischarge to the Aral Sea .

CONSEQUENCES OF THE ARAL SEA'S RECESSIO N

The drying of the Aral Sea has had major physical, ecolog-ical, and social-economic consequences The most important o fthese are discussed below .

I . Changes in the Sea's Physical Parameters . Between 1960 and1985, sea level fell by 11 .46 meters, area shrank by 23,600 k m2(35%), volume diminished by 652 km' (60%), and average salinitymore than doubled from 10 to 24 grams/liter (Figure 6) . I fsurface inflow to the Aral remains at the very low levels o frecent years (it averaged only 5 .2 km3/yr from 1981-85), the se awill continue to shrink well into the next century, with th earea stabilizing (assuming a residual inflow of irrigatio ndrainage water and groundwater totalling around 10 km3 ) at

4

12,000 k m 2 - 8% of its size in 1960 - whereas salinity will ris eto 140 g/l .

II. Exposure of Salt Covered Bottom . The quantity of sal tcontained in the Aral before the current recession has bee nestimated at 10 billion tons ° As the sea has retreated, enor-mous quantities of salt have been deposited as a loose layer o nthe 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 tamounts of salt have accumulated along the southern, eastern ,and northeastern coast of the Aral where a 15 to 75 km widestripe has been exposed . These salt covered areas are resistan tto natural and artificial revegetation and also are hearths fo rthe formation of salt/dust storms .

III. Salt/dust Storms Arising from the Dried bottom . One of themost serious problems connected with the drying of the Aral Se ais the blowing of salt and dust from its dried bottom . The mos tserious storms arise from the exposed bottom of the sea' snortheastern coast and lift material up to 2 km into th eatmosphere and carry it for up to 500 km (Figure 7) . The larg estorms are thought to have started and were first spotted o nspace imagery in 1975 . From 1975-81, 29 large storms wer econfirmed by Soviet scientists from analysis of Meteor (a hig hresolution weather satellite) images . Up to 10 major storm shave occurred in one year . Sixty percent of the observed storm smoved in a southwest direction which carried them over the delt aof the Amudar'ya River, a region with major ecological andagricultural importance . Twenty five percent of storms travel -led westward and passed over the Ust-Yurt plateau which is usedfor livestock pasturing . It has been estimated that 43 millio ntons of salt annually are carried from the sea's dried bottominto adjacent areas and deposited as aerosols by rain and dew

5

over 150,000-200,000 km 2 . These salts, particularly sodium bi-carbonate, sodium chloride, and sodium sulfate, are toxic t oplants, especially during flowering . In spite of the expectedincrease in the area of former bottom, the export of salt i spredicted to slightly diminish to 39 million tons/yr by 2000 a sa result of the exhaustion of deflatable salt, the leaching o fsalt into deeper layers, and through the process of diagensis o fthe older surface salts .

IV . Loss of the Sea's Biological Productivity . As the sea hasshallowed, shrunk, and salinized, biological productivity ha ssteeply declined and 20 varieties of native fish species hav enearly disappeared (Figure 8-A) . By the early 1980s, biomas sand phytoplankton had decreased 3 to 5 times compared to thei rpre-1960s levels whereas the haul of commercial fishes (48,00 0metric tons in 1957) declined to zero . As salinity continues t orise, even ocean species that have been introduced, such a sflounder, will be unable to survive . The large fish cannery a tMuynak, which was formerly on the Amudar'ya delta's shorelin ewith the Aral but is now tens of kilometers inland, has bee nforced to import fish for processing from distant regions ,including the Atlantic . With the end to commercial fishing, amainstay of the local economy, there has been an exodus o fpopulation from Muynak and many former fishing villages hav ebeen abandoned . Residual commercial fishing continues in del-taic lakes (e .g . Sudoch'ye in the Amudar'ya Delta) and in th etwo largest irrigation drainage water lakes that have forme d(Sarykamysh and Aydarkul') which are biologically rich . How-ever, the deltaic lakes are drying whereas levels of pesticide sand herbicides (from cotton field runoff) in fish caught i nSarykamysh and Aydarkul' are dangerously high, prompting a hal tto 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 dAmudar'ya rivers in their lower reaches has had devastatin geffects on their deltas . Distributary and even main channel shave dried or become deeply entrenched, spring inundation o ffloodplains has ceased and floodplain lakes have shrunk or dis-appeared (Figure 8-B) . Native vegetational complexes, mos timportantly Tugay forests (composed of dense, often impassabl estands of water-loving trees such as popular, willow, tamarisk ,ash, and buckthorn mixed with shrubs and tall grasses whic hfringe deltaic arms and channels to a depth of several kilo-meters) have degraded and disappeared (Figure 8-C) . Groundwater levels have dropped meters making it more difficult o rimpossible for hydrophytes and phreatophytes to obtain moisture .Deltaic desiccation has promoted the rapid expansion of desert-ification . The rich and diverse fauna of the delta whic hincludes wild boar, deer, jackel, many kinds of birds, and unti lrecent decades even a few tiger) have also greatly suffere dthrough alteration and disappearance of their natural habitats .The most serious effects have occurred in the huge Amudar'y aDelta . Here by 1980 more than 50 lakes with an aggregate areaof 1000 km 2 had dried, groundwater levels had declined from 3 t o8 meters, and tugay forests which covered 1,300 k m2 in 1961 haddecreased to around 50 km 2 .

VI . Climatic Changes Around the Aral Sea . The Aral influence sboth temperature and moisture conditions in an adjacent strip eestimated to be 50-80 km wide on its north, east and west side sand 200-300 km to the south and southwest . With the sea' scontraction these climatic influences have substantially dimin-ished leading to warmer summers, cooler winters, later sprin gand earlier fall frosts, a shortened growing season, lowere dhumidity, and an overall trend toward greater continentalit yaround the waterbody . The greatest changes have occurred in th eAmudar'ya Delta . For example, at Kungrad, now located about 100

7

km south of the Aral, comparison of the period 1935-60 wit h1960-81, indicates that relative humidity diminished 1 .4 fold ,the average May temperature rose 3-3 .2°C and that the averag eOctober temperature decreased 0 .7-1 .5° . There is fear that th egrowing season in the Karakalpak Autonomous Republic, located t othe sea's immediate south, may shorten sufficiently to adversel yaffect the raising of cotton .

VI . Declining Groundwater Levels Around the Aral Sea . The dro pof the Aral Sea has been accompanied by a decline of groundwate rlevels for a considerable distance from its shore . Sovie tscientists have estimated that a 10 meter drop of the Ara l(reached in 1984) would lower the level of ground and artesianwater by 5-9 meters in a 30 to 40 km coastal stripe and have adepressing influence from 60-100 km inland . A 15 meter se alevel drop (likely by the mid 1990s) could reduce groundwate rlevels by 7-12 meters in the coastal zone and affect the watertable 80-170 km away from the sea . Declining groundwater level shave had significant adverse effects outside the Amudar'ya an dSyrdar'ya deltas, drying wells and springs, degrading natura lplant communities, pastures and hayfields and generally contrib-uting to the spread of desertification .

VI . Estimates of Losses from the Aral's Recession . There are n oaccurate monetary estimates of the damage caused by the Aral' sdrop . However, Soviet scientists and economists have attempte dto place some preliminary "ballpark" measures on the majo rnegative changes that are more amenable to economic deter-mination . A 1979 study [K .I . Lapin and E .D . Rakhimov, "AnAttempt to Estimate the Social-economic Consequences of th eDesiccation of the Aral Sea," Problems of Desert Development ,No . 2 (1979), p . 90 . (in Russian)] concluded that aggregat edamages within the Uzbek Republic totalled 5 .4 to 5 .7 billio nrubles . A more recent evaluation [Gerasimov et al ., "The Aral

8

Sea Problem and

the Anthropogenic

Desertification o fRegion," Problems of Desert Development, No . 2

(1983) ,Russian)]

estimated

that

annual

damages only

in

the Ara lp . 29 (i nthe lowe r

reaches of the Amudar'ya (basically the delta region) were 92 . 6million rubles with the following distribution of losses (i nmillions 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 acontinuation of the low inflows characteristic of recent year sand lack of implementation of ameliorative measures, the se awill continue to shrink and sometime in the next centur ystabilize as a lifeless, residual brine lake . More water coul dbe supplied to the sea if consumptive irrigation withdrawal swere reduced and, thereby, river flow increased . However, irri-gation continues to grow here, although plans for future expan-sion have been scaled back under the Gorbachev regime . There i sa national campaign underway to improve water use in irrigatio nthrough such measures as reconstruction of old, inefficien tirrigation systems, automation and telemechanization of wate rdelivery facilities, and "programming" of harvests (involvin gthe use of simulation-optimization models to minimize inputs an dmaximize outputs under a set of production objectives and con-straints) . Since irrigation system efficiency (ratio of wate rwithdrawn 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 tof this "freed" water will likely be needed to irrigate newlands to produce more food for the region's very rapidly growin gpopulation 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 fdrainage water are estimated to have been generated in the Ara lBasin in the early 1980s . About 21 km3 of this already return sto rivers leaving 13 km' that evaporates from drainage wate rlakes or the desert . Some of this could be carried by pipe orspecial 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 construc-ting the special conveyance facilities (reportedly underway )will be high . Additionally, the two largest drainage wate rlakes, Aydarkul' and Sarykamysh (see Figures 2 and 3 for loca-tion), with areas in excess of 2000 km 2 each, and which hav edeveloped wildlife, fishery, and recreational value, would dry .It must be noted that the program to improve irrigation effi-ciency will significantly reduce the amount of drainage water .

Even assuming that 10-12 km' of drainage water could b edelivered to the sea, this water plus some groundwater inflo w(perhaps 3-4 k m3 ) would likely constitute the total discharge t othe Aral . Without further ameliorative measures, this woul donly support a sea of around 19,000 k m2 whose salinity would bevery high . In light of this reality, mitigative approache shave been suggested to "save" the Aral as an ecologically viabl ebut greatly shrunken waterbody and to reduce the adverse impact sof its recession . A number of schemes have been proposed t odivide the sea with dikes, preserving low salinity conditions i nlimited parts of it and allowing the remainder to dry or becom ea salt accumulator . Several of these are shown on Figure 9 .Discharge to the waterbody has dropped so rapidly and its areashrunken so greatly that designs 9-A, 9-B, and 9-C are "ob-solete" since it is unlikely there will be sufficient inflow t oimplement them . Design 9-D is sustainable, particularly if

1 0

facilities are built to deliver collector drainage water di-rectly to the sea . As part of this plan, the shoreline of th e"active" portion of the sea would be steepened by dredges s othat seasonal fluctuations in surface area leading to sal tdeposition on the shore would be minimized . Regardless of wha tmitigative scheme is implemented or even if no efforts are mad eto preserve the sea, measures must be instituted to stabiliz ethe salt covered former bottom and to greatly reduce the blowingof salt and dust from it . Field experiments are underway t odevelop 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 situationwould be to supplement it via the addition of water importe dfrom more humid regions . A project that would have done thi swas formulated in the 1970s and early 1980s by the Nationa lWater Management Design and Scientific Research Institut e(Soyuzgiprovodkhoz), a subagency of the Ministry of Reclamatio nand Water Management . The main purpose of this plan was t osupply more water for irrigation, but directly and indirectly i twould have provided more water to the Aral . The scheme wa senthusiastically supported by Central Asian Party and govern -mental officials . Water was to be diverted into the regio nfrom the Ob' and Irtysh rivers situated to the north in Wester nSiberia . Low dams, pumping stations, and a huge canal (pop-ularly named "Sibaral" - Siberian to the Aral Sea Canal) were t otransport water over a distance of 2500 kilometers as far as theAmudar'ya River (Figure 2) . The first phase of the scheme, tha twould have transferred 27 km3/yr, was in the final design phas eby 1985 and, it appeared, could be under construction by th elate 1980s or early 1990s .

After Gorbachev assumed leadership in 1985, the Siberian aswell as European transfer protects' fortunes waned rapidly . Heand his advisors saw the schemes as a poor use of scarce

1 1

resources and contended that less costly, more effective mean sof solving southern water problems were available . The trans-fers had been periodically attacked during the 1970's and earl y1980's as unnecessary and ecologically damaging by scientist sand writers from areas of proposed water export who believe dthey would severely damage their regions . But public doubt sabout the projects had been officially discouraged for severa lyears as they moved closer to implementation . By summer 1985 ,public criticism was again permissible and probably officiall yencouraged . Beginning in the fall of that same year, th eschemes and those who were directly or indirectly involved wit hthem were repeatedly (and sometimes viciously) attacked in th emain popular print media by a group of Russian national writer sand a number of scientists, including some academicians . Thecriticism tended toward exaggeration and, frequently, was scien -tifically and factually inaccurate . Nevertheless, in a dra-matic policy reversal, construction of the initial phase o fEuropean transfers was dropped from the 12th Five Year Plan a swas further design work on the Siberian project . In Augus t1986, a joint decree of the Central Committee of the Communis tParty of the Soviet Union and the Council of Ministers officall yordered a cessation of construction and design work on th eEuropean and Siberian projects . However, research on the scien-tific problems associated with water diversions, stressing eco-logical and economic concerns, is continuing .

In summary, the future of the Aral is not bright . The se acontinues to recede and salinize with a variety of sever eaccompanying ecological problems and economic losses . To besure, scientific study of the "Aral problem" and its amelior-ation has been a national effort since 1976 under the aegis o fthe State Committee on Science and Technology . Furthermore ,the decree ordering the cessation of work on diversion project sdirected that a complex program for the development of Central

1 2

Asia to 2010, considering the demographic, water management, an dagricultural situation, be formulated and presented to the USS RCouncil of Ministers not later than the first quarter of 1987 .Nevertheless, other than the reported start of construction of apipeline to carry some drainage water to the sea, no concret eactions of any significance are being taken . The Siberia ndiversion project has been cancelled, but its "resurrection" i nthe 1990s if the water management situation in the Aral Se aBasin continues to worsen, cannot be ruled out . Although partyand government officials from the republics adjacent to the Ara lSea are keeping quiet, the past few years have seen scientists ,writers, and journalists from this region angrily and sometime seloquently pleading in the regional as well as national pres sfor somekind of action to save the Aral, in their view anational if not world treasure, before it is too late . So fa rthese cries for help have fallen on deaf ears . Indeed, I wa stold by knowledgeable Soviet scientists during the fall of 198 7that the sea may already be beyond rescue .

SELECTED REFERENCE S

Azimov, Sarvar, "How to Save the Aral?" Literary Gazette ,November 26, 1986, p . 11 .

[in Russian] .

Dukhovnyy V . A . et al ., "The Problem of the Aral Sea and Natur eProtection Measures," Problems of Desert Development, No . 6 ,1984, pp . 3-15 .

[in Russian ]

Grigor'yev, Al . A ., "Large-scale Changes of the Nature of th eAral Region as Determined by Monitoring from Space," Problems o fDesert Development, No . 1, 1987, pp . 16-22 . [in Russian ]

Yusupov, E ., "How to Stabilize the Aral?" Truth of the East ,September 10, 1987, p . 3 .

[in Russian]

Figure 3: AVHRR IMAGE OF ARAL BASIN (7/3/86)

Image resolution is around 1 km. Dark tones indicate water and vegetate dareas (oases, irrigated lands, deltas and floodplains) . Lighter tone sindicate sandy and scrub desert . The lightest areas are playa lake bed sand salt flats . Satellite : NOAA-9 . Spectral Range : .58- .68 . Source :National Environmental Satellite, Data, and Information Service .

ure 4o

ARAL SE Alira I' k

Small Ara/ Sea

Sgr Dar' go R .

Yozhrozhden Ly e

Is lan d

Barsa-Ke I' me s

ISland

L.) o

Easter nBa 5 i n

Muynak

~0 14no6 Qa p~p

° a b

Sea LeeI S

4

r`

Rdudar ' yo R .L . Sudoc h' ye

50

1

53m (1960 )51m (1971 )

(1976 )48 m6 ( kn,43m (1984)

Source: Institute of Water Problems, USSR Academy of Sciences

(*) measured above Baltic Sea leve l

(based on data compiled by A . Ye . Asarin and V . N . Bortnik .)

Table 1 . AVERAGE ANNUAL WATER BALANCES FOR THE ARAL SEA [1]

1926-60[2] 1960-70[3] 1970-85[4 ]AVG . AREA (sq . km) 65,780 63,470 53,66 0

cubic cubic cubi ckm mm km mm km mm

GAIN[5] 63 .4 963 .5 51 .2 806 .7 22 .9 426 . 8RIVER DISCHARGE 55 .2 838 .6 42 .8 674 .0 16 .3 304 . 3PRECIPITATION 8 .2 124 .9 8 .4 131 .7 6 .6 122 . 6

LOSS 64 .1 973 .5 63 .3 997 .7 56 .2 1046 . 6EVAPORATION 64 .1 973 .5 63 .3 997 .7 56 .2 1046 . 6

AVERAGE NETVOLUME CHANGE 0 .7 10 .0 -12 .2 -191 .9 -33 .3 -619 .7

Source : calculated from data provided by the Institute of Wate rProblems, USSR Academy of Sciences (based on compilations o fA . Ye . Asarin and V . N . Bortnik) .

[1] Some figures do not correspond exactly to others because o fcumulative 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 t coveredformer bottom with blowing salt and dust is at left . The Amudar'ya Delta ,with clear evidence of desertification, and Lake Sarykamysh are in th ebackground . The former delta of the Syrdar'ya is in the left foreground .Shuttle altitude : 178 km . Source : EROS Data Center .

A . Sudak (pike-perch, Lucioperca lucioperca) caught in the Ara lin 1978 . A large, tasty fish (reaching 4000 grams and 7 5cm), sudak are semi-anadromous and require low salinity .By the early 1980s, this species disappeared from the Ara lSea as average salinity rose above 15 g/l .

B . The main channel (Engineernyy Uzlyak) of the Amudar'ya nea rits entrance to the Aral in October 1982 . Only 2 km'reached the sea from both the Amudar'ya and Syrdar'ya i nthis year .

C . Tugay (floodplain forest-scrub) along the bank of a distri-butary channel of the Amudar'ya Delta in July 1982 . Th earea of this vegetation community has greatly decreased a sthe delta has desiccated owing to reduced river flo wthrough it and the recession of the Aral Sea .

Source : photographs courteoy of Dr .

M . I .

Novikova , Institute0 Water Problems, Academy of Sctences, USSR .

B

LEGEND FOR FIGURE 9

1 - active (freshened and circulating) part of sea ; 2 -isolated (salt accumulating) part of sea ; 3 - drie dpart of sea ; 4 - earthen dam ; 5 - spillway; 6 -location and direction of inflow and outflow fo ractive part of se a

A . Separation of northern "small sea" in 1980 and deepe rwestern part of sea in 1985 . Average annual physica lcharacteristics 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 ; surfaceinflow - 30 km' ; outflow - 15 km' .

B . Isolation of northern part of sea in 1980 and wester npart in 2000 . Average annual physcial characteristic sof active sea : area - 30,000 km2 ; volume - 285 km 3 ;level - 46 .6 m ; salinity - 13-15 g/l by 2050 ; surfaceinflow - 30 km 3 ; outflow - 15 km 3 .

C. Separation of eastern part of sea from western wit hcanal connecting small northern sea . Average annua lphysical characteristics of active sea : area - 20,00 0k m2 ; 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 onsea surface - 1 .51 km' ; groundwater inflow - 1 . 6 km3outflow - dependent on inflow above minimum ; evapor-ation from sea surface - 11 .6 km3 .