15 july 2020

Central Asia news

Academician Bekdjan Tashmukhammedov: Rainfall control may double Uzbekistan's water resources

08.07.2008 10:56 msk

Andrei Kudryashov (Tashkent)

Interview Uzbekistan

Bekdjan Tashmukhammedov
Professor Bekdjan Oibekovich Tashmukhammedov is the head of the Physics of Membranes Laboratory at the Institute of Physiology and Biophysics of the Uzbek Academy of Sciences. Chairman of the MAB UNESCO National Committee, Professor Tashmukhammedov actively promotes radically sophisticated solutions to the water, land, and food problems Uzbekistan and its Central Asian neighbors are facing. For instance, Tashmukhammedov invited geneticist Norio Murat of the Biology Institute (Nagoya, Japan) to Tashkent in 2004 and suggested the cultivation of gene-modified rice and vegetables with modified seaweed genes to plant on the saline lands of Uzbekistan.

Uzbekistan has raised no official objections, so far, to construction of the Koksarai water reservoir on the Syrdarja River in Kazakhstan, which began on June 26, 2008. Uzbek ecologists, however, do become upset when thinking about the effect the reservoir may have on filling the Aidar-Arnasai lake system, as well as on the climate of the Tashkent region.

Ferghana.Ru news agency approached Tashmukhammedov for comment. The academician denied the existence of any particular threats to the Uzbek environment from the planned water reservoir in Kazakhstan. Further, Tashmukhammedov suggested rainfall control as a means of dealing with shortages of water in the Syrdarja basin, the problem affecting all countries of the region.

Ferghana.Ru: How come Uzbek scientists and experts never object to construction of the Koksarai water reservoir (actually, a compensating reservoir)? When the decision to build it was considered in Kazakhstan itself, Anatoly Ryabtsev of the Water Economy Committee of the Kazakh Agricultural Ministry advanced the idea that neighbors of Kazakhstan might raise objections because the project would restrict water drainage from the Shardarja water reservoir to the Aidar-Arnasai lake system...

Bekdjan Tashmukhammedov: Kazakhstan has no other options left. In fact, the water reservoir in question will only have an insignificant impact on the ecological situation in Uzbekistan. It is being built much lower on the Syrdarja than the Shardarja water reservoir and will, therefore, receive surplus water from winter floods. Filling the Shardarja water reservoir, the floods will, therefore, be deprived of much of their destructive force. The governments of Uzbekistan and Kazakhstan will hopefully reach an agreement to keep up annual "sanitary" water drainage from Shardary to the Arnasai Valley, necessary for the ecological balance of the Aidar-Arnasai lake system.

Our neighbors were always cooperative in the past in the matter of emergency surplus releases of water that enabled Kazakhstan to cope with the consequences of winter floods. Suspension of the regular release of water from Shardary to Arnasai, beyond the established norms, will stop the flooding of the Aidarkul that makes the lake system ecologically unstable. Submergence of shores and banks and a rise of the ground water level in Uzbekistan cost it thousands of hectares of pastures. Instead of wasting time and effort to prevent overfilling of the Aidarkul, we will, instead, be able to concentrate on stabilization and the rational use of this unique body of water.

Ferghana.Ru: The Koksarai water reservoir will be only 5.5 meters deep, its surface area will be 466 square kilometers. What about evaporation, then? Will it have any negative effect on the climate in Tashkent and its environs? Ecologists say that with the huge water tables of Aidarkul, Arnasai, Shardary, and Koksarai the climate in Tashkent is already becoming "seaside climate". Summer here is nearly five months long. Does it mean that the capital of Uzbekistan should expect to swelter in scorching heat between May and October?

The Aidar-Arnasai lake system appeared on salt marshes in the Kyzylkum desert when 2.7 cubic kilometers of water were urgently dumped from the Shardarja water reservoir, during a catastrophic Syrdarja flood in March 1969.

The flat water, whose surface totals 2,175 square kilometers, stabilized into an anthropogenesis ecological system that alleviated consequences of the drying up of the Aral Sea. Advised by the UN and the Global Ecological Foundation, the government of Uzbekistan established the Nuratau-Kyzylkum reservation on the shores of the lakes.

Surplus releases of water from the Shardary to Arnasai in winter floods resumed in the late 1990s and promptly overfilled the lake system. Area surface of the lake system reached 3,175 square kilometers by 2004.

Some ecologists claim that the breach of the western, extremely salinated, part of Aidarkul and its ensuing drying up will push almost 1 million tons of acidic salts into the atmosphere. It will have a thoroughly negative effect on cotton crops and facilitate the thaw of the Tien Shan ice caps. Others point out that fluctuations of the ground water level in the lake system may bring sulfur-filled hydrogen up to the surface (they are generated by decay of flora on the submerged shores).

Specialists have been working on the project of a drainage channel from the western end of Aidarkul since 2004. Others were assigned, then, to come up with ideas for what was to be done to stabilize the system when the drainage from the Syrdarja to Arnasai stopped.

Expert Nikolai Golelkin claims that 1.5 cubic kilometers is all the annual drainage the Aidar-Arnasai ecological system needs to retain its stability. Even without drainage from Shardary, however, the lakes will retain their ecological importance for another four decades.

Bekdjan Tashmukhammedov: Doctors claim that the extreme dryness of the air and the continental climate, typical of this region, are uncomfortable but no worse than that. As for the natural processes, however, the region could certainly do with some additional humidification, which will only creates better conditions for agriculture. The tempo and the scale of the catastrophic desertification spreading all over Uzbekistan in connection with the torrefaction of the Aral Sea is attributed, to a considerable extent, to the disappearance of the humid water cushion that used to hover above the Aral once. The Aidar-Arnasai lake system alleviated this process to a certain degree. Additional humidification of air in the middle Syrdarja will have a favorable effect on weather and natural conditions. There will be more rainfall and stream flowing for irrigation. It's just that we must learn a more rational use of all this moisture.

Ferghana.Ru: Koksarai is being built to protect the South Kazakh region and its economy from catastrophic winter floods of the Syrdarja. What if it is a waste of money? It definitely seems that the Syrdarja basin is entering a period of a dramatic shortage of water. The flow this year is one-tenth of what it was in 2007. So, what if they build the water reservoir only to discover that they have no water to fill it with?

Bekdjan Tashmukhammedov: Two factors should be taken into account here. The natural water regime cycle is as follows: 2-3 wet years (years with an abundance of water, in other words) precedes six to seven dry or low water years. It exists even now, even allowing for the effect the global warming up has on it. There are, however, changes caused by human activity, which is the second factor. Syrdarja winter floods and low water in summers began in the 1990s when water reservoirs in Kyrgyzstan, once built by Soviet specialists for purposes of irrigation, were put to work for the intensive production of electric power. These days, Kyrgyzstan even aspires to charging its neighbors for the water that flows to the Syrdarja from the Naryn cascade of water reservoirs.

Ferghana.Ru: And Uzbekistan and Kazakhstan refuse it, of course. Right?

Bekdjan Tashmukhammedov: Right, because it collides with the regional traditions and, also importantly, with international law and practice. Sovereign states are not supposed to introduce changes into the hydrological regime of trans-frontier rivers without the consent of neighbors. Had the responsibility been mine, I'd have said, in no uncertain terms, that Uzbekistan would never pay for water. Anyway, we have politicians and diplomats to explore avenues leading to mutually acceptable agreements, and we have scientists and officials to seek non-political solutions to problems. Disturbed by the surplus winter releases of water into the Syrdarja from the Naryn cascade, and shortage of water in summers, Uzbekistan has already built two new water reservoirs in Kenkul and Rezaksai. The Ferghana Valley is no longer affected by winter floods. They gave way to seasonal accumulations of water necessary for irrigation later on. Why wonder, then, that Kazakhstan decided to emulate it and build the Koksarai compensating reservoir, which will convert destructive floods into something a national economy might use?

Ferghana.Ru: And yet, not even these technical solutions solve regional problems. No water reservoirs, compensating or otherwise, will help Uzbekistan or Kazakhstan much without sufficient volumes of water from the upper Syrdarja.

Bekdjan Tashmukhammedov: Indeed, the overall tendency looks somewhat bleak. Glaciers intensively thaw in the areas where Syrdarja and Amudarja begin. The Pamir and Tien Shan ice caps are 20-40% smaller than they were in the mid-20th century. Their thaw rate is 1% a year now. Uzbekistan has already encountered a dramatic shortage of water. Farming taking up 84% of the water resources, becoming the worst affected. Three-fourths of all water is lost in filtration and through evaporation from irrigation ditches, as well as in the process of irrigation itself. Intensive irrigation facilitates soil salinization. Over 50% of arable lands in Uzbekistan are made up of saline soils. Fresh water resources, needed for their restoration and rehabilitation, are nearly exhausted. That is why I suggested the use of these saline lands for cultivation of saline-resistant crops, by the way. Even that, however, does not solve the problem of water resources or, rather, the problem of their shortage. Using sophisticated techniques designed and even tested in Uzbekistan, we may control rainfall above vast territories and that will actually double water resources in the region.

Ferghana.Ru: That's a tempting idea but, scary, at the same time. Right out of SF novels, you know.

Bekdjan Tashmukhammedov: As a matter of fact, my suggestion is based on the work done by the Central Asian Research Institute Glavgidromet or SANIIGMI and the successful tests its specialists ran in the 1970s and 1980s. The experiments were run at three testing sites in the basin of the Pskem River in the Tashkent region, in Kashkadarja, and in the Ferghana Valley. Well-known in academic circles, these experiments confirm the possibility of the artificially induced effects on clouds for the purpose of increasing rainfall in this region. To solve the problem of water shortages, we need a state service of rainfall control staffed with adequately trained personnel and using specialized aircraft. These latter may even be assembled at the Tashkent Aircraft Factory, by the way.

Ferghana.Ru: The idea is radical, indeed. Does Uzbekistan have sufficient finances to carry it out?

Bekdjan Tashmukhammedov: There are regions in Uzbekistan where there is practically no rainfall the year-round. For example, rainfall in the center of the Kyzylkum desert usually amounts to less than 80 millimeters. Causing rains there will be extremely difficult and prohibitively expensive. On the other hand, there are areas with abundant rainfall, say, up to 2,000 millimeters a year. The Pskem River basin is one of them. Needless to say, it is easier and cheaper to try and increase rainfall where it is formed naturally. Even a not particularly intensive interference may double it.

As for the choice of the areas where we should try to apply our knowledge, they are determined by the direction of movement of air masses. Ordinary seasonal rains in Uzbekistan are usually caused by warm and humid air masses coming in from the Atlantic. Encountering the mountains, these air masses rise even higher where the air is colder, and that's how condensation occurs. The methods invented by SANIIGMI specialists leave the general energetics of the process well alone, but correct key mechanisms of rainfall formation. That's what makes it relatively cheap.

This spring (a period of great disappointment for our farmers) was a period of the so-called metastable conditions of rain clouds. In other words, even specialists were hard pressed to say whether showers were about to begin or no rain at all would fall. A great deal of nuances and factors are involved. There is an updraft, and drops do form in the clouds. But if the temperature up there is not cold enough, or whenever there is a shortage of condensation nuclei (motes of dust or tiny ice crystals), these drop are too small. They evaporate again in lower levels of the atmosphere, well before they reach the surface. Quite frequent in our region as it is, this condition of instability is perfect for rainfall control. Just a slight correction is all it will take to ensure showers.

Rains fall in Uzbekistan unevenly. Rainfall in the plains, that take up over two-thirds of the territory, varies between 100 and 200 millimeters. In the Kyzylkum desert and near the Aral Sea it is under 80 millimeters. The rainfall level in the mountains and nearby reaches 900 millimeters. Rainfall in spring amounts to 30-50% of the annual amount, winter is 25-40%, autumn brings 10-20%, and summer is only about 16%. Air humidity amounts to 60-65% year round.

Water resources of Uzbekistan are estimated at 5,060 cubic kilometers a year. In total, only 12.2 cubic kilometers are formed in Uzbekistan itself, while the rest comes from the Tien Shan and Pamir ranges in Kyrgyzstan and Tajikistan.

Methods may differ. It is possible to use an aerosol of silver nitrate suspended matter for condensation, but that is fairly expensive. It is also possible, on the other hand, to use frozen carbon dioxide granules instead of nitrate silver so that they will form additional centers of condensation by lowering the temperature around them.

Ferghana.Ru: As it is, natural calamities (floods, landslides, mudslides, hail, tornados) are typical of Central Asia. What if what you suggest brings about some unpredictable and catastrophic consequences?

Bekdjan Tashmukhammedov: As a matter of fact, the energy we will bring in into the natural process is not sufficient to cause any destructive or unpredictable consequences. Positive results, on the other hand, will be quite impressive. The economic effect depends on the size of the area, you know. If, for example, we operate only above the areas where the annual rainfall amounts to 200-300 millimeters, then the volume of moisture doubled by artificially caused rains will amount to 20-25 cubic kilometers of water, about the annual rainfall and exactly where and when we need it.

Ferghana.Ru: Hearing all these optimistic forecasts and fantastic suggestions from Uzbek scientists, observers cannot help getting the impression that Uzbekistan will stop at nothing to avoid the necessity of seeking compromises with its neighbors and partners...

Bekdjan Tashmukhammedov: Even Kyrgyzstan, the country that forces the matter of water fees because it, itself, is affected by its shortage that affects the Kyrgyz electric power production industry, may find rainfall control techniques quite handy. Kazakhstan, financially stable as it is, may grow interested in a radical and sophisticated solution to the problem of agricultural development of the middle Syrdarja region and restoration of the Smaller Aral.

Also, importantly, all our countries will soon encounter common challenges of staggering magnitude. One may be as skeptical about global warming as it pleases him, but climatic changes in Central Asia are already undeniable. Particularly in Uzbekistan, with its considerable population. All the same, I retain optimism because sophisticated techniques may make even the global warming turn into a positive factor. I only hope that our politicians and state officials will heed academic circles. The materials the UN World Weather Service recently published state that rainfall control methods will be used in over two-thirds of the planet by 2025. The warming up will make the atmosphere more humid. It's time we started learning how to extract this moisture and its use.