Vakhsh River Research Articles

Spatial distribution of cosmogenic 10Be derived denudation rates between the Western Tian Shan and Northern Pamir, Tajikistan

The northward motion of the Pamir mountains relative to Eurasia results in uplift and shortening of the Pamir and Tian Shan orogens. The Vakhsh River catchment (Tajikistan) is situated along a thrust system in the collision zone between the Northern Pamir and the Western Tian Shan. In this study, spatial variations in catchment-wide denudation rates are reported from the Vakhsh River catchment with in situ-produced cosmogenic 10Be and 26Al of 22 samples from active river channels. Samples distributed along 140 km of the main Vakhsh River yield denudation rates between 1.28 ± 0.16 to 1.94 ± 0.26 mm/yr. In detail, samples from rivers draining the Northern Pamir indicate denudation rates of ~1.7 mm/yr, and a river draining the Alai Valley indicates denudation rates of 1.14 ± 0.14 mm/yr. In contrast, rivers draining the Western Tian Shan show increasing denudation rates from 0.18 ± 0.02 mm/yr in the west to 2.70 ± 0.36 mm/yr in the east, coincident with a small increase in the fluvial normalized steepness index (ksn). Measured 26Al/10Be ratios range from 5.2 to 7.6, indicating a low influence of sediment storage and reworking of partially shielded material. In addition, locations resampled one year later confirm previously calculated denudation rates along the main trunk. Analysis of in situ-produced cosmogenic 10Be from depth profiles collected from a sequence of terraces preserved along the main trunk of the Vakhsh River indicate terrace incision starting at ~3 kyr as well as paleo-denudation rates ranging between 1.75 ± 0.54 to 2.01 ± 0.39 mm/yr (2 s.d. errors). All these results suggest consistent high denudation rates in the Northern Pamir block, and a spatial (along strike) gradient in Western Tian Shan denudation rates. The most likely explanation for the spatial gradient in Western Tian Shan and Vakhsh River denudation rates is a regional gradient in tectonic rock uplift.

THE STUDY OF WATERSHED TOPOGRAPHY CHARACTERISTICS IN VAKHSH RIVER BASED ON ZY3-DSM

Abstract. The Vakhsh River is one of the major rivers in Tajikistan. The quantitative analysis of watershed topography and developmental characteristics in Vakhsh River catchment can reflect the morphological characteristics of the region, which is of great significance for revealing the quantitative relationship between the hydrological and the geomorphological process. In this paper, the D8 algorithm and the spatial analysis method were used to extract the river networks, the catchment boundary profile lines and the longitudinal valley profile lines of the four major tributaries in the Vakhsh River from the ZY3-DSM of 10 meters resolution. On this basis, five quantitative indices including the frequency of wave, amplitude of wave, gully density, the longitudinal slope and roundness rate were used to analyze the watershed landform and its development degree. According to the experimental results, the catchment have a high surface complexity and a mature landform. Yovonsu river catchment which is in the downstream of Vakhsh River is oval and has low terrain complexity with large frequency and small amplitude. Among the midstream and upstream, the Mukson River has developed into geriatric terrain that is the most mature and has the highest surface complex, while the Obikhingon River and the Kizilsu River have developed into a stable maternal terrain. In terms of topography, the boundary elevation of the Obikhingon is basically in accordance with the normal distribution, while the Kizilsu and the Muksu show a peak state with elevations of 4,000–5,000 m and 5,000–5,500 m, respectively.

‘Tajikistan’s Turksib’: infrastructure and improvisation in economic growth of the Vakhsh River valley

ABSTRACTThis article analyses the paradoxically central role of a railroad in Soviet economic growth in southern Tajikistan’s Vakhsh River valley during the 1930s. Constructed as a secondary service road of the Vakhshstroi agro-industrial complex, it was not meant to support enterprises throughout the region. Because of the republic’s lack of roads, however, unrelated freightage operations gravitated to the Vakhsh Railroad and made it the unintended mediator of the developing geography of Soviet movement. By examining how the narrow gauge line was used in unplanned ways, I find that state building under Stalin was characterized by improvisation in labour and mobility. Furthermore, the material conditions of transportation limited the locations of economic possibility in unanticipated ways. This case demonstrates that studying the use of infrastructure can further historical understanding of causes, effects and chronologies of economic life in the Stalin era.

Managing the water–energy–food nexus: Gains and losses from new water development in Amu Darya River Basin

Summary According to the UN, the population of Central Asia will increase from its current approximately 65 million people to a well over 90 million by the end of this century. Taking this increasing population into consideration, it is impossible to project development strategies without considering three key factors in meeting the demands of a growing population: water, food and energy. Societies will have to choose, for instance, between using land and fertilizer for food production or for bio-based or renewable energy production, and between using fresh water for energy production or for irrigating crops. Thus water, food and energy are inextricably linked and must be considered together as a system. Recently, tensions among the Central Asian countries over the use of water for energy and energy production have increased with the building of Rogun Dam on the Vakhsh River, a tributary of the Amu Darya River. The dam will provide upstream Tajikistan with hydropower, while downstream countries fear it could negatively impact their irrigated agriculture. Despite recent peer reviewed literature on water resources management in Amu Darya Basin, none to date have addressed the interconnection and mutual impacts within water–energy–food systems in face of constructing the Rogun Dam. We examine two potential operation modes of the dam: Energy Mode (ensuring Tajikistan’s hydropower needs) and Irrigation Mode (ensuring water for agriculture downstream). Results show that the Energy Mode could ensure more than double Tajikistan’s energy capacity, but would reduce water availability during the growing season, resulting in an average 37% decline in agricultural benefits in downstream countries. The Irrigation Mode could bring a surplus in agricultural benefits to Tajikistan and Uzbekistan in addition an increasing energy benefits in Tajikistan by two fold. However, energy production in the Irrigation Mode would be non-optimally distributed over the seasons resulting in the most of hydropower being produced during the growing season. Neither operation mode provides optimal benefits for all the countries, emphasizing how difficult it is to actually reach a win–win scenario across the water–energy–food security nexus in transboundary river basins.

Wildscapes In Ballyhooland

Writing the history of yet another Stalinist shock construction site cannot be an end in itself. Hence, the article treats the story of the Vakhsh River Valley Project, a showcase irrigation scheme located at the Soviet border with Afghanistan, not merely as a humanitarian, economic and environmental disaster. While deprivation and fear were key factors that hindered knowledgeable engineers and capable managers from reigning in an unruly natural environment, the article scrutinizes how Stalinist political ambition and Soviet institutional disorder intertwined with unfavorable environmental conditions which, ultimately, prevented the irrigation and colonization scheme from succeeding. The imminent collapse of the Vakhsh Project in 1937, thus, revealed some fundamental limitations of Stalinist governance in a politically and ecologically sensitive borderland.

STRUCTURAL DESIGN OF NEW LINING FOR DIVERSION TUNNELS: ROGUN DAM AND HPP PROJECT

Rogun dam is a 335m high clay core rockfill dam which will be constructed on Vakhsh River in Tajikistan. Originally, two diversion tunnels with similar geometry were designed for discharging the seasonal floods, up to 3290m3/s. River diversion was carried out in November 1987 and a 45m high rockfill cofferdam was constructed. However, because of two collapses in the diversion tunnels, the cofferdam was overtopped in May 1993. Reconstruction of these tunnels started in 2009 and the collapsed areas were repaired. Nowadays, the design of complementary rehabilitation including new concrete lining for those parts of the tunnels will be used as tailrace tunnels are underway. The present paper describes the present conditions of diversion tunnels No. 1 and 2, explains the procedure used for the structural design of these tunnels, and presents the results of such design.

Rates of river incision across the main tectonic units of the Pamir identified using optically stimulated luminescence dating of fluvial terraces

Calculated incision rates along the Panj, the main river of the Pamir, are used to investigate any influence by tectonics or climate on the architecture of the river. The depositional ages of Panj River terraces were calculated using optically stimulated luminescence (OSL) dating of terrace sand. Fluvial incision rates were generated by integrating the terrace depositional ages with accurate kinematic GPS measurements of terrace heights above the modern Panj. We investigated 16 terraces along the Panj at the western Pamir margin and one terrace from the Vakhsh River to the north of the Pamir. The results reveal brief periods of fluvial deposition over the past 26kyr. The oldest Panj terrace depositional ages coincide with early MIS 2 and MIS 2/1 glaciations on the Pamir Plateau. Younger terrace ages have no apparent link with glacial cycles. Terraces with varying heights above the modern Panj at different localities yielded similar depositional ages. This suggests that local conditions have determined fluvial incision rates. Combining all of the terrace measurements, the average incision rate of the Panj over the last 26kyr has been ~5.6mm/yr. A high mean incision rate of ~7.3mm/yr was calculated from terraces where the Panj has cut a steep-sided valley through the Shakhdara dome. Significantly lower incision rates (~2–3mm/yr) were calculated from terraces where the Panj flows along the southern boundaries of the Shakhdara and Yazgulom domes. At those localities, graded segments of the Panj River profile and increased valley widths are indicative of local base levels. Downstream of the Yazgulom dome, river incision rates are generally lower (~4–5mm/yr) than the Panj average. However, there is one exception where higher incision rates (~6mm/yr) were calculated upstream of the Darvaz Fault Zone, a major tectonic feature that forms the western boundary of the Pamir. The Vakhsh River terrace to the north of the Pamir yielded a lower incision rate (~3mm/yr) compared to the Panj average. Variation in incision rates along the Panj does not correspond to changes in rock type or river catchment area. Instead, incision rates appear to have been primarily influenced by river capture across the southern and central metamorphic domes of the Pamir. Wherever the Panj cuts these domes it displays a convex river profile. The combination of localized river profile convexity and changes in incision rates across the Pamir domes indicates that the dome boundaries have been active recently.

Water, Food, and Energy Security: An Elusive Search for Balance in Central Asia

The development and use of water resources in the Amu Darya Basin remain under debate in the face of increasing population and associated scarcities in water, food, and energy. The upstream riparian, the mountain nation of Tajikistan, wishes to develop its hydropower potential. Three downstream states wish to sustain or increase their economic benefits from water used for irrigation. Growing tensions among the riparian countries on the Vakhsh River, a tributary of Amu Darya, have halted development of Tajikistan’s proposed Rogun Dam. This paper examines the potential for mutually beneficial water development and allocation of water resources to sustain demands for water, food, and energy. Using long-term data on the Basin’s energy potential, water supplies, irrigated land, and crop water demands, this paper analyzes total economic welfare for a future 20-year time horizon. Two water supply scenarios for each of two policy choices are examined. Results show that a constrained economic optimization operation of the Dam has the potential to increase farm income for each riparian country, while producing considerable benefits in hydropower for Tajikistan. Political negotiation among the riparian states and much better data will be needed to discover and implement potential gains indicated by this study.

State-Building, Migration and Economic Development on the Frontiers of Northern Afghanistan and Southern Tajikistan

The Kunduz River Valley of northern Afghanistan and the Vakhsh River Valley of southern Tajikistan followed what initially appear to be vastly different trajectories. Despite these two adjacent areas having had much in common throughout many periods of history, the present-day region of northern Afghanistan was eventually taken under the control of the Afghan state while the areas north of the Amu Darya and Panj River were to become part of the Soviet Union. However, instead of a divergent course of development and state-building, these two regions were subjected to very similar patterns of agricultural development and migration policies. “Empty” areas were to be populated, by force if necessary, wetlands were to be drained for agriculture, and cotton farming was to become pre-eminent. The end result in both areas was the creation of a socially diverse and economically significant region that was fully integrated into the modern state's economy and politics. This article analyzes and compares the motives and implementation of the state-building projects in both of these now domestically important regions and finds remarkable similarities despite the obvious differences in the structure of the Afghan and Soviet states.

Model studies of conditions for closure of the Vakhsh River at the site of the Sangtudinskaya HPP-1

Model studies of conditions for closure of the Vakhsh River at the site of the Sangtudinskaya HPP-1

Horizontal deformations of the near-surface parts of the earth's crust in the region of the Nurek hydroelectric station

relative to the conditionally stationary point and conditionally stationary direction. The method of tensor analysis can be another method of representing the processing results. Calculations of components of plane continuum tensors are based on known equations of continuum mechanics relating elongation along the measured line to the strain tensor component [3]. If strains that occurred over a long period of time are investigated, it is necessary to take the mean annual elongations of the lines as the base. The method of calculating plane continuum strain tensors is presented in detail in monograph [2]. Geologic Characteristics of the Reservoir Region. The Nurek reservoir is located in the northern part of the Tajik depression, in the region of the middle course of the Vakhsh River. With respect to geologic structure and tectonic development the territory of the reservoir is located in the Tajik depression. The depression is bounded on the north by a regional tectonic disturbance extending from the west to the east, the western part of which is called the Ilyak fault and the eastern part the Vakhsh overthrust. On the whole this fracture -- The llyak-Vakhsh marginal fault -- had a controlling influence on the development of the Tajik depression. The Tajik depression is a Late Paleozoic sedimentary basin that was deformed and subsided during the Alpine orogen. The thickness of the sedimentary cover in the northern part of the depression is 5-6 km. Faults of a lower order relative to regional faults extend near the foot of fold-mountain ranges. These fractures belong to the most recent orogenic stage of development. Their maximum activity is conf'med to the Quaternary phase, including the Recent. Faults are often expressed in the relief. The range of neotectonic movements reaches 3-4 km. The

Comparative characterization of the engineering-geological prediction and actual conditions of construction of the Rogun hydroelectric station

UDC 624.131.3:626/627 During construction of the Rogun hydro development, engineering-geological and geophysical investigations were carried out in construction excavations and pits and on-site observations were made. The information accumulated permits evaluating the actual conditions of construction and the quality of the engineering-geological prediction on which the designs were based. We will recall the characteristics of the geological structure of the site of the Rogun hydroelectric station. The valley of the Vakhsk River in the stretch of the hydro development is curved in plan and represents a steep-sloped canyon with a depth up to 500 m and length of about 1 km. The stretch is composed of a Lower Cretaceous stratum of intercalated sandstones and siltstones, the layers of which extend perpendicular to the valley and are inclined at an angle of 65-76 ~ toward the lower pool. These are strong rocks with average and severe jointing. In a structural respect the stretch of the site represents a tectonic block bounded by second-order faults - Ionakhsh and Gulizindan - which extend parallel to the layers of the rocks and dip at an angle of 80-85 ~ to the same side. The Ionakhsh fault intersects the river in the base of the upstream shoulder of the dam, the Gulizindan fault is traced from the upstream to the downstream pool outside the main structures of the hydro development. In their kinematic type, these faults are reversed faults with a displacement of about 2 kin. Upper Jurassic formations, represented by argillites and halite, are "drawn out" along the faults. Along the Ionakhsh fault halite is recorded at a depth of 20 m below the water level in the Vakhsh River and its thickness does not exceed 3-8 m. The halite bed is covered with Jurassic argillites with a thickness of 15-20 m, which in turn are covered with Cretaceous deposits; the bottom of the bed is cut by the Ionakhsh fault. Due to the difference of the dip angles of the rock layers (65-75 ~ and fault plane (80-85~ the thickness of the halite bed increases with depth. The presence of halite was presumed also along the Gulizindan fault, in connection with which measures on protecting the salt from dissolution and prevention of concentrated seepage of water from the reservoir were planned here. A detailed survey conducted during construction showed that there is no salt (halite) along the Gulizindan fault. In addition to those described, smaller faults are developed in the rock mass. They are related to the Ionakhsh fault, extend parallel to it, and dip at an angle of 30-50 ~ toward the upper pool. The largest of these faults, No. 35, intersects the entire block bounded by the Ionakhsh and Gulizindan faults. The displacement along fault No. 35 reaches 120 m, the thickness of the crush zone is up to 30 m. The region of the Rogun hydrostation is characterized by high tectonic activity: the seismicity of the region is intensity 9, contemporary movements are recorded along relatively large faults. The vertical component of the rate of these movements along the Gulizindan and Ionakhsh faults is 1.5-2.0 mm~r and it does not exceed 1 mm/yr along fault No. 35. Contemporary tectonic activity is due to high natural stresses of the rock mass: in the stretch of the site the horizontal stresses are equal to 15-18 MPa and the vertical to 14 MPa, which is 1.4 times greater than the stresses from the weight of the overlying rocks. Investigations showed that the field of natural stresses of the mass is constant in time: an increase of stresses is transformed into movement along the faults, which causes dynamic equilibrium of the system. The rock mass composing the stretch of the site is distinguished by high deformation properties (modulus of deformation E = 4000-8000 MPa) and low permeability (Kp < 0.01 m/day). The exception is a part of the mass adjacent to the head of the bed: as a consequence of dissolution of the halite around it, the mass is decompressed and its permeability is 0.5-1.0 liter/rain. The decompressed zone is extended along the head of the halite, its cross-sectional area is close to 200 m 2. The halite

Kinematic characteristics of tributaries of the Vakhsh River in the flooding zone of the Rogun reservoir

Kinematic characteristics of tributaries of the Vakhsh River in the flooding zone of the Rogun reservoir

Damming the Vakhsh River channel at the site of the Rogun hydroelectric station

1. The use of material in the form of large-block elements, short and long, when damming mountain rivers with considerable falls on the embankment exceeding 5–10 m makes it possible to construct a damming embankment of a compact profile with minimum consumption of material, with the predominant use of elements in the form of concrete cubes weighing 10 tons as the most technological and effective. 2. The use of these bundles has presently become possible owing to the presence of modern powerful equipment. With the proper level of organization of the works, this equipment can carry our damming without special complications in the shortest possible time.

Crustal strain in the rogoun dam area

In recent years much attention has been paid to the study of crustal movements within tectonically active regions. The present work is specially of interest since it deals with the site where one of the largest hydroelectric plants in the world is being built. The erection of the Rogoun HPP on the Vakhsh river involves the filling of a 320 m high dam using local materials and the construction of an underground-head hydroelectric unit with substations and auxiliary services. The work gives an evaluation of features and rates of seismotectonic deformations in two layers of the earth's crust (0.9 km and 10–25 km), obtained for a period of 28 years, within an area of 3 thousand km 2 around the HPP. These data allowed us to determine the complex block structure of the region. Based on instrumental data concerning strain processes occurring within the construction site, an evaluation is given of recent movements in the areas adjoining the Ionakhsh fault and the dislocations in its feather jointing.

Crustal strain in the Rogoun dam area

In recent years much attention has been paid to the study of crustal movements within tectonically active regions. The present work is specially of interest since it deals with the site where one of the largest hydroelectric plants in the world is being built. The erection of the Rogoun HPP on the Vakhsh river involves the filling of a 320 m high dam using local materials and the construction of an underground-head hydroelectric unit with substations and auxiliary services. The work gives an evaluation of features and rates of seismotectonic deformations in two layers of the earth's crust (0.9 km and 10–25 km), obtained for a period of 28 years, within an area of 3 thousand km2 around the HPP. These data allowed us to determine the complex block structure of the region. Based on instrumental data concerning strain processes occurring within the construction site, an evaluation is given of recent movements in the areas adjoining the Ionakhsh fault and the dislocations in its feather jointing.

Deformation of the rock mass during construction of the Nurek hydroelectric station

Observations of the deformations caused by construction of the Nurek hydroelectric station (on the Vakhsh River, USSR) were carried out during and after the construction period. Observations were made both in the dam foundation and in the reservoir flanks in vertical and horizontal directions. Observation data indicate that the dam foundation experienced uneven settling both over area and in time. The maximum deformations were found to correspond to the maximum loads. These actual data indicate that the construction of a dam and creation of a reservoir cause deformations of the rock mass in an extensive region, and the specific settlement depends upon the strength and density of the rocks composing the foundations and also upon the pressure created by the dam's weight. The geodetic observations are continuing at the Nurek hydroelectric station to monitor the possible movements of the rock blocks and the effects of these movements on the normal operation of individual structures of the hydrostation. 3 references, 2 figures, 4 tables.

Passing Vakhsh river flows during construction of the Nurek hydroelectric plant

The scheme developed for operating high-head segmented gates on eccentric supports by means of temporary installations, as has been highly recommended, may also be employed on other construction projects in similar situations.

Runoff accounting at hydroelectric stations of Tadzhikistan

1. On streams with a sequence arrangement of hydroelectric stations it is necessary to have at least two stream-gauging stations of the hydrometeorological service: upstream of the first reach of the sequence (inflow station) and downstream of the last reach (outlet station). 2. Operation of turbine flowmeters under conditions of the mountain rivers of Tadzhikistan, the water of which contains a large amount of suspended silty sediment, showed that they are rapidly put out of operation owing to clogging of the impulse tubes with silt and entry of air into them. Under such conditions it is apparently best to use pneumohydraulic apparatus. 3. The discrepancy in the mean monthly discharges past hydrostations on the Vakhsh River, determined by the data from operation and the gauging stations of UGMS, reaches 20–30%; the causes of the discrepancies are, on the one hand, the inaccuracy of flow measurement at the gauging stations of UGMS and, on the other, the noncorrespondence of the calculated discharge capacity of individual discharge structures to the actual. 4. To reduce the discrepancies it is necessary to increase the accuracy of hydrologic measurements and observations at gauging stations of UGMS; at hydroelectric stations it is necessary to carry out full-scale rating of the turbines and conduits and to check these characteristics periodically (once every five years), and also to refine the curves of the dynamic relations of the storage capacity of reservoirs to their water levels.

The rogun hydraulic development on the Vakhsh River

The rogun hydraulic development on the Vakhsh River