Amu Darya Research Articles

Pipe Dreams: Water and Empire in Central Asia's Aral Sea Basin by Maya K. Peterson (review).

Reviewed by: Pipe Dreams: Water and Empire in Central Asia's Aral Sea Basin by Maya K. Peterson Marianne Kamp (bio) Pipe Dreams: Water and Empire in Central Asia's Aral Sea Basin By Maya K. Peterson. Cambridge: Cambridge University Press, 2019. Pp. xxii + 399. The continuity of a vision for irrigation is on display in Peterson's Pipe Dreams, where the author's research reveals that Imperial Russia's dreams of constructing vast new systems of canals in Central Asia's arid lands found even more grandiose fulfillment when the Soviet government implemented its development plans. At times engineers and investors drew on indigenous Central Asian knowledge, but more frequently, top-down plans ran into material, social, economic, and natural obstacles. Peterson highlights three inherently contradictory goals that the Russian and Soviet governments pursued: turning Kyrgyz nomads into sedentary farmers, opening Central Asia to settlement by colonizers, and making Central Asia into the land of cotton. Starting in the 1860s, when Russia's geographers first set foot in the newly conquered lands, they imagined rerouting the lower reaches of the Amu River to reach the Caspian Sea and watering land that they saw as empty desert—believing it to be unused because it was not farmed. All that was required to make it useful was investment, expertise, and labor. A collection of diaries, reports, and letters to the Romanov Grand Duke Nikolai Konstantinovich allows Peterson to examine the repeated failures and moderate successes of canal building through the Hungry Steppe between Bekabod and Jizzakh (in today's Uzbekistan), not only as a water-control project, but also through the lenses of the Russian peasants who settled there. The sources attest to the peasants' apparent gratitude to the Russian government, and they illustrate an innovative social experiment that combined indigenous Central Asian and colonizer labor to provide both groups with irrigable fields. Those human dimensions are Peterson's contribution to what was otherwise a small-scale water engineering project that has attracted historians' attention, from a 1927 account by V. V. Tsinzerling to Julia Obertreis's Imperial Desert Dreams (2017), primarily because of its abundant archival traces rather than because of any transformative dimensions. [End Page 1185] Competition between indigenous peoples and colonizers is abundantly evident in Peterson's wholly novel research on irrigation projects in the Chu River valley, near today's Bishkek, Kyrgyzstan. As seen by Russian administrators, the lush grasslands that Kyrgyz herders apportioned through kin networks needed to be plowed and farmed to reach their productive capacity. Russian administrators crafted legal means to seize land, and settlers from Russia arrived in large numbers. Experts who designed the canal scheme were thwarted by lack of investment, so that the building project dragged on through World War I and into the Civil War years that followed the Russian Revolution. Project administrators recruited Uyghur and Dungan labor migrants from Xinjiang and contracted for prison labor, while Russians and Kyrgyz fought over land—the massacres inspiring the nascent Bolshevik government to restrict colonization. Pipe Dreams follows administrative visions for controlling water through a series of episodes from Imperial Russia to the Soviet years. In the 1890s, Russia's successful introduction of the highly productive American Upland strain of cotton (Gossypium hirsutum) directed attention to the possibilities for expanding irrigation into dry lands; after the Revolution, increasing cotton production became the obsession of Soviet-era plans for Central Asia, to the detriment of grain growing and livestock husbandry. Soviet-style investment featured massive, highly publicized building projects, one of which was the 1930s Vakhshstroi in southern Tajikistan, whose goal was populating the Vakhsh valley with indigenous cotton growers. Archives reveal the abundant problems that beset this venture, which relied on attracting tens of thousands of laborers to resettle in the area, including labor turnover and hydrology engineering failures resulting in many years of missed targets. Unlike Vakhstroi—where Soviet engineers took pride in using heavy machinery despite being plagued by problems—the Grand Fergana Canal, as well as many subsequent large canals in Soviet Uzbekistan, was dug by several hundred thousand Uzbek peasants in a celebrated "people's construction" campaign, using what Peterson views as the most extreme degree of state...

Depositional and Diagenetic Controls on Reservoir Quality of Callovian-Oxfordian Stage on the Right Bank of Amu Darya

Based on the detailed analysis of sedimentology, diagenesis, and petrophysics, this study characterized the Middle-Lower Jurassic Callovian-Oxfordian carbonate reservoirs of 68 key wells in the Amu Darya Basin and assessed the controlling factors on the quality of the target intervals. We identified 15 types of sedimentary facies developed in seven sedimentary environments using sedimentary facies analysis, such as evaporative platform, restricted platform, open platform, platform margin, platform fore-edge upslope, platform fore-edge downslope, and basin facies. The target intervals went through multiple diagenetic stages, including the syndiagenetic stage, early diagenetic stage, and middle diagenetic stage, all of which had a significant impact on the reservoir quality. Main diagenetic processes include dissolution and fracturing which improve the reservoir quality as well as cementation, compaction, and pressure solution that reduce the reservoir quality. By analyzing the reservoir quality, we identified nine fluid flow units and five types of reservoir facies. Among them, the dissolved grain-dominated reservoir facies is of the highest quality and is the best storage and flow body, while the microporous mud-dominated reservoir facies of platform fore-edge downslope and open marine facies is of the lowest quality and could not become the flow unit unless it was developed by fracturing.

IRRIGATSION KANALLARDA DARYO OQIZIQLARINING TARKIBIY QISMI TAHLILI

The article is devoted to the analysis of mechanical and chemical composition of river sediments in irrigation canals. Movement of river drains, which constitute an integral part of water resources, in the riverbed, hydraulic structures and on cultivated lands, forms a sort of a global cycle in nature. According to hydrological studies, only in the very bed of Amu Darya, it is possible to observe movement of a huge amount of runoff throughout the year. From the monitoring of irrigation channels used in Uzbekistan, it is known that for efficient and safe operation of many structures in an optimal mode, scientifically sound management and efficient use of river flows negatively affect the lack of methods and technologies, as well as effective solution of these issues does. Experiments conducted in natural field conditions helped to draw conclusions based on the study of mechanical and chemical compositions of river sediments along the length of canals.

Contrasting Fate of Western Third Pole's Water Resources Under 21st Century Climate Change

AbstractSeasonal melting of glaciers and snow from the western Third Pole (TP) plays important role in sustaining water supplies downstream. However, the future water availability of the region, and even today's runoff regime, are both hotly debated and inadequately quantified. Here, we characterize the contemporary flow regimes and systematically assess the future evolution of total water availability, seasonal shifts, and dry and wet discharge extremes in four most meltwater‐dominated basins in the western TP, by using a process‐based, well‐established glacier‐hydrology model, well‐constrained historical reference climate data, and the ensemble of 22 global climate models with an advanced statistical downscaling and bias correction technique. We show that these basins face sharply diverging water futures under 21st century climate change. In RCP scenarios 4.5 and 8.5, increased precipitation and glacier runoff in the Upper Indus and Yarkant basins more than compensate for decreased winter snow accumulation, boosting annual and summer water availability through the end of the century. In contrast, the Amu and Syr Darya basins will become more reliant on rainfall runoff as glacier ice and seasonal snow decline. Syr Darya summer river‐flows, already low, will fall by 16%–30% by end‐of‐century, and striking increases in peak flood discharge (by >60%), drought duration (by >1 month) and drought intensity (by factor 4.6) will compound the considerable water‐sharing challenges on this major transboundary river.

Post-Soviet changes in cropping practices in the irrigated drylands of the Aral Sea basin

Water withdrawals for irrigated crop production constitute the largest source of freshwater consumption on Earth. Monitoring the dynamics of irrigated crop cultivation is crucial for tracking crop water consumption, particularly in water-scarce areas. We analyzed changes in water-dependent crop cultivation for 650 000 km2 of Central Asian drylands, including the entire basin of the Amu Darya river, once the largest tributary to the Aral Sea before large-scale irrigation projects grossly reduced the amount of water reaching the river delta. We used Landsat time series to map overall cropland extent, dry season cropping, and cropping frequency in irrigated croplands annually from 1987 to 2019. We scrutinized the emblematic change processes of six localities to discern the underlying causes of these changes. Our unbiased area estimates reveal that between 1988 and 2019, irrigated dry season cropping declined by 1.34 million hectares (Mha), while wet season and double cropping increased by 0.64 Mha and 0.83 Mha, respectively. These results show that the overall extent of cropland in the region remained stable, while higher cropping frequency increased harvested area. The observed changes’ overall effect on water resource use remains elusive: Following the collapse of the Soviet Union, declining dry season cultivation reduced crop water demand while, more recently, increasing cropping frequency raised water consumption. Our analysis provides the first fine-scale analysis of post-Soviet changes in cropping practices of the irrigated areas of Central Asia. Our maps are openly available and can support future assessments of land-system trajectories and, coupled with evapotranspiration estimates, changes in crop water consumption.

Callovian-Oxfordian sedimentary microfacies in the middle of Block B on the right bank of the Amu Darya Basin, Turkmenistan

The right bank of the Amu Darya Basin enjoys abundant natural gas resources, on which the Callovian-Oxfordian strata in the middle of Block B serve as the major horizons for natural gas production. However, the characteristics and distribution patterns of the sedimentary microfacies in these strata are yet to be further explored. Based on the analysis of data on drilling, logging, cores, and thin sections from 29 typical wells, as well as the regional sedimentary background, this study inferred that the middle of Block B evolved from the Callovian ramp platform into the Oxfordian rimmed platform. Moreover, this study determined that the inner-ramp intertidal-subtidal shallow-water subfacies mainly developed during the Callovian and transitioned into the shallow shelf subfacies during the Oxfordian. This study identified eight sedimentary microfacies, namely reef knoll, reef-shoal complex, bioclastic shoal, psammitic shoal, bioherm, lime mud mound, intershoal (intermound), and static-water mud. Based on research into the high-precision sequence-sedimentary microfacies framework, this study built a geological model for the development of sedimentary microfacies in the study area. According to this geological model, the sedimentary microfacies in the study area are characterized by vertical alternation of reef-shoal complex, bioclastic (psammitic) shoal, bioherm, and intershoal microfacies. Moreover, they show the development of reef knoll, reef-shoal complex, bioclastic (psammitic) shoal, and bioherm (or lime mud mound) laterally from west to east, with the physical properties of the reservoirs deteriorating from west to east accordingly. The microfacies of reef-shoal complex and the bioclastic (psammitic) shoal predominate in the study area, and their deposition and development are controlled by sequence boundaries and are also affected by paleo-landforms. The Oxfordian reef-shoal complexes were largely inherited from the Callovian uplifts and show lateral seaward progradation.

Hydrocarbon migration and accumulation in the large Samandepe Gas Field in the chardzhou step-fault zone, Amu Darya Basin, northeastern Turkmenistan: A response to the tectonic evolution of the northern margin of the tethys

The mechanism of large-scale hydrocarbon accumulation in the Tethys domain has long been of interest to petroleum geologists. Located in the northern margin of the Tethys, the Amu Darya Basin (ADB) is well known for its large, indeed giant, gas fields. However, there has been surprisingly little research on the mechanisms of hydrocarbon accumulation in the basin. This paper investigates the accumulation history of the Samandepe Gas Field, a large condensate gas field in the Chardzhou step-fault zone in the northeastern ADB. Trap evolution in the basin is analyzed, the oil and gas sources and hydrocarbon charging periods are determined, and the process of hydrocarbon migration and accumulation explored to establish the relationship between hydrocarbon accumulation and the tectonic evolution of the Tethys. Geophysical logging, organic geochemistry, fluid inclusion analysis, basin modeling are used for analysis. The results show that hydrocarbon accumulation in the Samandepe Gas Field occurred in two stages. First, a lithological ‘large trap’ formed in a barrier reef belt in the Late Cretaceous Santonian, before the present anticline structure of the gas field formed. This trap was filled with oil generated in Upper Jurassic marine source rocks, forming a lithological paleo-oil reservoir. In the second stage, at the end of the Paleogene, the large trap was reformed as structural traps with reef-shoal reservoirs. Natural gas generated from coal-measure source rocks in Middle and Lower Jurassic strata migrated along basement faults, filling the traps. Excess natural gas displaced the oil, some of which dissolved in the gas, forming ‘gas washing’-type secondary condensate oil and creating a structural condensate oil-bearing field. The inherited paleo-uplift in the step-fault zone is crucial to large-scale hydrocarbon accumulation in the ADB.

Chronology of the Late Pleistocene Caspian Sea hydrologic changes: A review of dates and proposed climate-induced driving mechanisms

This paper provides a review of the dates used to define major hydrologic changes in the Caspian Sea during the Late Pleistocene that includes the Early Khvalynian and Hyrcanian highstands and the Atelian lowstand, and it discusses their driving mechanisms. Dates obtained by 14C (that are the most numerous), by OSL and by U/Th for samples that are well identified in the literature through their geographic location and their laboratory number, are considered. Samples derive from sediments both in the current Caspian Sea coast and in its Middle and Northern basins. Most of dates concern the Early Khvalynian highstand while less abundant ones correspond to the Hyrcanian highstand and Atelian lowstand that preceded the Early Khvalynian. The review of these Late Pleistocene dates provides an overall revision of the hydrologic changes that the Caspian Sea experienced. Accordingly, the Early Khvalynian highstand presents two major phases. The first Early Khvalynian phase (hv1-1) took place between 36.0 and 22.0 cal kyr, and water level reached ca 0 m a.s.l. Its second phase (hv1-2) is characterised by the deposition of the so-called Chocolate Clays especially in the Northern Peri-Caspian and took place between ca 22.0 and 12.5 cal kyr BP with a water level rise until at least 40 m a.s.l. between ca 17 and 13 cal kyr BP. Before the Early Khvalynian highstand, the Caspian water level underwent a lowstand between at least 70.0 and 36.0 kyr, i.e. the Atelian lowstand, which was interrupted by the Hyrcanian highstand. During the late stage of the Atelian lowstand, between 43.5 and 42.9 and 36.0 cal kyr BP, the water level decreased between more than −60 m a.s.l. and less than - 90 m a.s.l. at 42.0 cal kyr BP. The importance of the water level drop in the early stage of the Atelian regression between ca 70 and 55.2 kyr could not be estimated but according to seismic profiles, it was much less pronounced than later. The dates for the Hyrcanian highstand range from 55.2 (or even before) to 43.5–42.9 cal kyr BP and the water level reached at least 0 m a.s.l. in its late phase. Through this synthesis, the origins of water inflows into the Caspian Sea could be suggested for the upper part of the Early Khvalynian transgression: it matches with a very large inflow of meltwater from the southern front of the Scandinavian Ice Sheet; the fluvio-glacial waters from the ice cap discharging to the Caspian Sea via the Volga River. Concerning the Hyrcanian transgression, meltwater inputs from the glaciers of western High Asia can be proposed, the fluvio-glacial waters being transported into the Caspian Sea by the Syr Darya and Amu Darya (via the Aral Sea or bypassing it).

Occurrence, sources and spatial distribution of n-alkanes in surface soils from the Amu Darya Delta, Uzbekistan, arid Central Asia

Central Asia (CA) has attracted global attention because of either water scarcity or ecosystem degradation. The Amu Darya Delta (ADD), one of the most important oases in CA, is endowed with valuable wetlands and biological resources that provide good ecosystem services to inhabitants. However, the region has experienced climate warming and large-scale anthropogenic changes since the last century. To assess the influences of anthropogenic interventions on the soil environment in this area, surface soil samples collected from the ADD were analysed for aliphatic hydrocarbon fractions and five heavy metals (HMs; including Cd, Zn, Cu, Ni and V). The results indicated that the n-alkanes extracted from surface soils were composed of homologous series from C14 to C35. Relatively high abundances of short-chain n-alkanes (<n-C21) were observed in cluster 1 samples (mainly from the lakeshore of the Aral Sea), while significantly high abundances of mid-chain (n-C21 to n-C25) and long-chain (n-C26 to n-C32) n-alkanes were found in cluster 3 samples, which were distributed in urban and agricultural drainage areas. In addition, very-long-chain n-alkanes (>n-C33) occurred in most surface soils, which might be a sign of a hot and arid climatic environment. Notably, almost all samples presented a clear even carbon dominance of short-chain n-alkanes, especially for cluster 1, which possibly represented the influence of hydrocarbon contamination and highly saline carbonate environments in addition to bacterial degradation. The biomarker indices and HM enrichment index indicated greater effects of crude oil pollution on cluster 1 (specifically samples 2, 4, 5, 6, 13, 16 and 34) and anthropogenic activities such as traffic emissions and agricultural drainage on cluster 3 samples. The results of this study provide evidence that the n-alkane composition and abundance in surface soils respond sensitively to anthropogenic interventions, arid climate and petroleum hydrocarbon pollution.

HYDROCHEMISTRY OF HIGH-MOUNTAIN PAMIR RIVERS: FORMATION, CHANGES AND INFLUENCE ON THE CHEMICAL COMPOSITION OF IRRIGATION WATER

The purpose of the research is to analyze the prospects for the agriculture development in the Central Asian region and Tajikistan in particular, in terms of identifying the main favorable and constraining factors for the further agriculture development. The Pyanj river is one of the main tributaries of the Transboundary Amu Darya River in the Central Asian region, whose waters are a source of drinking water supply for the population and 80% used for irrigation of agricultural land. The trend of deteriorating water quality of Central Asian River systems recently has been increasing, and monitoring water quality from the formation zone to the downstream of the rivers is a problem in the region. The statistical methods and Pearson correlation to the meteorological conditions monitoring of the river basins were used. In the Laboratory of Environment and Geology of the Department of Geological Sciences of the University of Colorado at Boulder (USA), as well as in the Laboratory of Moisture Chemistry of the Institute of Arctic and Alpine Research (USA) by use of an inductively coupled plasma mass spectrometer (ICP-MS) and ion chromatography was conducted the element analyses of waters. The physical and chemical analyses of water samples was conducted using the “TaLab” spectrophotometer following the relevant state standards. The suitability of water for irrigation were determined by the calculation of the coefficients of sodium adsorption (SAR), the percentage of sodium (Na%), the percentage of sodium solubility (SSP), and the percentage of exchangeable sodium (ESP). The contribution of the Gunt River to the enrichment of the main Pyanj River with Fe, Co, Ni, Sr, Ca, Mg, Na, and K elements are established. The assessment of the natural water quality of the Pyanj and Gunt rivers for irrigation was carried out using various index methods, such as SAR, ESP, SSP and %Na.

Fracture Properties and Their Impacts on Performance in Carbonate Reservoir, Central Block B on the Right Bank of Amu Darya

Abstract The Callovian-Oxfordian carbonate reservoir in central Block B on the right bank of Amu Darya is composed of different mechanical and petrophysical layers, where the tectonic fractures have major influences on both the performance and production of the low-permeability reservoir. The development of the tectonic fractures is mainly controlled by the mechanical properties of rocks (e.g., lithology, rock texture, porosity, and shale volume), and the differences in the development of tectonic fractures leading to the high production intervals are restricted preferentially due to fractured mechanical layers. Our study results show that the three main tectonic fracture systems are developed in the Callovian-Oxfordian Stage, including the fracture systems caused by extension movement, compression movement, and fold deformation. Specifically, high-angle extensional fractures and conjugate shear fractures are generally caused by extension movement, which are of small apertures and are mostly fully mineralized and have little impact on fluid flow. Medium- and low-angle extensional fractures as well as conjugate shear fractures are generally caused by compression movement where the strike is nearly parallel to the present-day maximum horizontal stress. These fractures have large aperture and good connectivity with strong flow conductivity of the fluid. However, fewer tectonic fractures are caused by fold deformation. The main properties of natural fractures, such as fracture length, fracture density, fracture aperture, fracture porosity, and stress sensitivity as well as their impacts on the Callovian-Oxfordian reservoir performances, are described herein. We conclude that the tectonic fractures have slight impacts on porosity albeit significant impacts on permeability. Hence, the well placement and well type are optimized under the guidance of the study results.

ÖZBEK TARİHİ VE KÜLTÜRÜNE GENEL BİR BAKIŞ

Türkistan Türk boyları arasında dilleri ve edebiyatları üzerinde ençok çalışılan etnik gruplardan birisi Özbeklerdir. Bugünkü Özbekistan’ın doğusunda Tacikistan ve Kırgızistan, batısında ve kuzeyinde Kazakistan, güneyinde ise Afganistan ve Tacikistan bulunmaktadır. Aral Gölü, Kazakistan ve Özbekistan içinde kalmaktadır. Amu Derya Nehri’nin bir kısmı Türkmenistan ile olan sınırını teşkil etmektedir. Ülkenin doğusunda Üst Yurt Platosu bulunmakla beraber Turan Çöküntüsü ve Kızıl Kum Çölü önemli bir yer işgal etmektedir. Ayrıca Zerefşan Irmağı da bu ülke toprakları içerisindedir. Ülkenin doğusunda Üst Yurt Platosu bulunmakla beraber Turan Çöküntüsü ve Kızıl Kum Çölü önemli bir yer işgal etmektedir. Tanrı Dağlarının bir ucu Özbekistan’a kadar ulaşmaktadır. Bununla birlikte tarihi belgelerde Çingiz Han’ın ölmeden evvel torunu Şiban’a Uralların doğusu, Aktübe ve Turgay civarlarını yurt olarak verdiği yazılıdır. Dolayısı ile Öz Bek Han’a yardımcı olmaları sebebiyle Şibanlılar ile Öz Bek Han’ın emrindeki kitlelere daha sonradan Özbekler denmeye başlandığını belirtmekte fayda vardır. Bugün Özbekistan Cumhuriyetinde pamuk üretilen toprakların genişliği 30 milyon hektarı aşmaktadır. Pamuk ekilen arazilerin miktarı yiyecek üretiminin artırılması yararına biraz azaltıldı ise de, Özbekistan yönetimi pamuğu ülkenin dünya ekonomisine sunabileceği temel mal olarak görmektedir. Bunun yanısıra hayvancılık da önemli bir gelir kaynağıdır. Özbekistan bütün bu kısa süre içinde birçok yenilik yapmıştır. Herşeyden mühimi kendi parasını tedavüle çıkarmış, yabancı sermayeler ve yatırımcılar teşvik edilmiş, ticaret, bankalar ve sigorta kanunları değiştirilerek, yeniden düzenlenmiştir. Ayrıca Özbekistan coğrafyası Türk dili ve merkezi olması hasebiyle yüzyıllarca Türk kültürünün ve folklorunun gelişmesine yataklık etmiştir. Özbekistan bölgesi, Türkistan’ın eğitim bakımından en köklü yapısına sahiptir. Özellikle bağımsızlıktan sonra Özbekistan’da kültür ve eğitim faaliyetleri çok hızlı gelişmeye başladı. Özbek Türkleri Türk kültürüne bugüne kadar binlerce eser kazandırmıştır. Bugün eski Rus kültür politikaları sebebiyle, Özbek Türklerinin ayrı bir millet olma hevesleri söz konusu ise de, tarihi hakikatler hiçbir zaman değiştirilemez. Sovyet Rusya bütün Türkistan’da olduğu gibi Özbekistan’da da milli bir kimlik yaratmış olmasına rağmen, onlar Türk milli kültürünü özümsemişlerdir. Sovyetlerin dağılmasıyla Özbekler, Rus ve Bolşevik yönetimin baskısından kurtulmuş olmanın verdiği coşku ve heyecanla zaten hiçbir zaman kaybetmedikleri benliklerini daha da güçlendirmek için olanca hızlarıyla köklerine dönmeye yöneldiler. İktisadi zorluklarına rağmen özlerinin ve parlak geçmişlerinin bir parçası olan tarihi yapılarını, mescitlerini, türbelerini, medreselerini tamir ediyorlar, yeni camiler yapıyorlar. Yıllarca süren ateist propaganda kampanyaları sonucu, dini bilgileri eksik kalan eski ve yeni kuşaklara İslâm dininin kurallarını, Kur’an-ı Kerim’in esaslarını öğretmeye çalışıyorlar. Özellikle bağımsızlıktan sonra Özbekistan’da kültür ve eğitim faaliyetleri çok hızlı gelişmeye başladı. Bunun göstergelerinden biri de Türkiye ile yaptıkları eğitim andlaşmalarıdır. Özbekistan egemenlikten sonra 2000 civarında talebesini Türkiye’ye göndermiş, bunlar Türkiye’de iki yıl kadar eğitim almıştır. Özbekistan’ın nüfusu 2020 yılı tahminlerine göre 34.5 milyon civarındadır. Yüzölçümü 447.400 km² olan bu Türk cumhuriyetinin önemli kentleri başşehir Taşkent, Semerkant, Fergana, Buhara, Karşi, Ürgenç, Nukus, Andican ve Namangan gibi yerlerdir. Sınırları içerisinde ayrıca Karakalpak Özerk Cumhuriyeti bulunur ki, 165.000 km² kadar olan bu bölgenin nüfusu da 1.850.000 civarındadır. Özbekistan’da 80’in üzerinde şehir mevcut olup, ülke idari yönden 12 vilayete (oblast) ayrılmaktadır. Yeni bağımsızlık kazanan Türk Cumhuriyetleri arasında Azerbaycan’dan sonra en çok Türk ve Müslüman nüfusa (% 80) sahip ülke Özbekistan’dır.

Spatial and Temporal Assessment of Remotely Sensed Land Surface Temperature Variability in Afghanistan during 2000–2021

The dynamics of land surface temperature (LST) in Afghanistan in the period 2000–2021 were investigated, and the impact of the factors such as soil moisture, precipitation, and vegetation coverage on LST was assessed. The remotely sensed soil moisture data from Land Data Assimilation System (FLDAS), precipitation data from Climate Hazards Group Infra-Red Precipitation with Station (CHIRPS), and NDVI and LST from Moderate-Resolution Imaging Spectroradiometer (MODIS) were used. The correlations between these data were analyzed using the regression method. The result shows that the LST in Afghanistan has a slightly decreasing but insignificant trend during the study period (R = 0.2, p-value = 0.25), while vegetation coverage, precipitation, and soil moisture had an increasing trend. It was revealed that soil moisture has the highest impact on LST (R = −0.71, p-value = 0.0007), and the soil moisture, precipitation, and vegetation coverage explain almost 80% of spring (R2 = 0.73) and summer (R2 = 0.76) LST variability in Afghanistan. The LST variability analysis performed separately for Afghanistan’s river subbasins shows that the LST of the Amu Darya subbasin had an upward trend in the study period, while for the Kabul subbasin, the trend was downward.

Evaluation and Application of MSWEP in Drought Monitoring in Central Asia

Thanks to the large scope, high spatial resolution, and increasing data records, satellite-based precipitation products are playing an increasingly important role in drought monitoring. First, based on the data from ground sites, the long-term Multi-Source Weighted-Ensemble Precipitation (MSWEP) precipitation product was evaluated in respect to drought monitoring. Then, based on the MSWEP product, the drought trends and the spatiotemporal characteristics of the drought events in four major basins (Amu Darya Basin, Syr Darya Basin, Chu-Talas River Basin, and Ili River Basin) in Central Asia, which have relatively dense gauge sites, were studied. The Standardized Precipitation Index (SPI) and the run theory were used to identify drought events and describe their characteristics. The results showed that MSWEP can effectively capture drought events and their basic characteristics. In the past 40 years, the study area experienced 27 drought events, among which the severest one (DS = 15.66) occurred from June 2007 to September 2008. The drought event that occurred from June 1984 to October 1984 had a drought peak value of 3.39, with the largest drought area (99.2%). Since 1881, there appeared a drying trend and a wetting trend in the Amu Darya River basin and the Ili River basin, respectively. No obvious wetting or drying trend was found in both the Chu-Talas River basin and the Syr Darya basin. Since 2016, the drought area has been on the increase.

Пресмыкающиеся пустынных равнин Юго-Западного Таджикистана: пространственное распределение, плотность населения и структура сообществ

Population density of reptiles in four desert areas of southwestern Tajikistan was estimated in spring 2018–2019. The structure of reptile communities in seven typical landscapes was described. The highest species diversity and population density were observed in sandy landscapes. Seven species of psammobionts formed the basis of these reptile communities. Among them Phrynocephalus interscapularis (56.4), Crossobamon eversmanni (27.8), Eremias lineolata (15.6), Eremias scripta (13.0) had the highest distribution and high population density (individuals/hectare). The relationship of cohabitating species was considered. The highest total population density of reptiles (89.0 ind./ha) was discovered on sandy ridges along the Amu Darya. On the loamy plain the population density of four species was 8.4 ind./ha, and on the foothill plain 2.4 ind./ha. Eremias nigrocellata (2.0 ind./ha) dominated in reptile communities on solid ground. In total, 25 species of reptiles inhabit the desert plains of Southwestern Tajikistan. 17 out of 25 (68%) species are included in the national Red Data Book. The level of endemism and similarity of reptile fauna in desert areas were high. Fauna similarity indices calculated according to Sørensen were 0.9–0.8. These values indicate close contact and connection between desert communities. The formation of the reptile fauna in southwestern Tajikistan occurred as a result of dispersal of Turanian species across the left bank of the Amu Darya River from Turkmenistan. They moved to the right bank due to the changes in the riverbed at the Pleistocene Epoch. The absence of some reptile species (Teratoscincus scincus, C. eversmanni, Phrynocephalus mystaceus, E. lineolata, Eremias grammica, E. scripta, etc.) in Northern Afghanistan along the border with Tajikistan is explained by the lack of herpetological study of this territory. Their habitat in the area is highly probable. Isolation and autonomy of desert areas in the Amu Darya valley create the opportunity for formation of new taxonomic forms. Examples are lizards E. scripta ladzinni and P. interscapularis sogdianus. The desert plains of Southwest Tajikistan have a small area and are subjected to significant anthropogenic pressure. Protection of small species, including lizards (Phrynocephalus raddei, P. mystaceus, Varanus griseus) and snakes (Eryx tataricus, Spalerosophis diadema, Boiga trigonatum, Naja oxiana, Echis carinatus) is needed. For widespread and numerous psammobiont species (P. interscapularis, E. lineolata, E. grammica, E. scripta, C. eversmanni) there is no threat of extermination at the moment.

Академик В. В. Бартольдтің ғылыми мұрасындағы кейбір тарихи географиялық мәселелер

The article considers the importance of the scientific branch of historical geography based on the work of Academician V.B. Barthold, who is the founder of the historical geography of Central Asia. Before proceeding to the consideration of historical and geographical works of the scientist, the authors analyzed the specifics of historical geography and the place of the subject in the modern world. This study compares different definitions of the subject, given by representatives of historical and geographical sciences. Besides, the main attention is paid to the methods of research and sources of historical geography. The authors of the article reveal the relevance of the issues of historical geography in the scientific heritage of the scientist orientalist, Academician V.В. Barthold. Among them, the author describes the confluence of the Amu Darya River with the Caspian Sea, the development of irrigation systems in Turkestan and the relationship between society and nature, the impact on these objects in the Middle Ages. Also, the article considers the arguments of V.В. Barthold based on various written sources and describes the confirmation of his judgment by archeological finds of later period. Thus, the authors point to the importance of historical and geographical research in modern science

Sustainability for the Watershed Management in Afghanistan: Example from Amu River Basin

The Amu River Basin, located in northeast Afghanistan, is the second largest basin. Therefore, a general concept of the importance and value of watershed management has been reviewed. Too little water at a given time can be a disaster (e.g., draughts), and too much water available at the same time is also a tragedy (e.g., in the form of floods). Sustainable water management needs to have a moderate water flow, maintenance of the water quality, mitigation of water flows to minimize soil erosion, recharging of groundwater, and conservation and recycling. This paper will help understand the different elements and aspects of watershed management in Afghanistan and its interactions with technology, economics, institute, and natural resources. The importance of contributing to water and land management is linked with the people's livelihood.

Morphometric Analysis of Baghlan Province for Amu River Basin in Afghanistan using Remote Sensing and GIS

Baghlan province is located in north of Kabul and surrounded by Bamyan, Kunduz,Parwan, Takhar, and Samangan provinces. It lies on the core route to the north and North-eastern regions of Afghanistan, which in terms of geographical location (coordinates) 29 degrees and 31 minutes north latitude and 58 degrees and 48 minutes east longitude, it is located 230 km from Kabul along the Kabul-Mazar highway; In the past, this province had 12 districts, which has now been raised to 15 districts, but in our current study, it will discuss 12 districts, which are the same 15 districts; 15 districts were canceled because there were no changes in the calculations of morphometric analysis. The different morphometric analysis explains the physical appearance of the watershed, which are suitable for the areas of land development, soil protection, topography rise, and soil erosion (Horton, 1945). This study discloses that DEM and GIS method in calculating morphometric drainage parameters and their effect on hydrological features at the watershed level is suitable than the conservative methods. The complete basin means bifurcation ratio (Rb) is 2.43, which shows that the drainage pattern is partial by geographical structure. Doshi and Khinjan districts have a high elongation ratio (Re), Ruggedness number (Rn), basin relief (Bh). It shows that peak discharges and erosion are high in these basins. This study is very beneficial for applying rainfall aggregation and watershed management.

Links of Hydrogen Sulfide Content With Fluid Components and Physical Properties of Carbonate Gas Reservoirs: A Case Study of the Right Bank of Amu Darya, Turkmenistan

Hydrogen sulfide (H2S) in carbonate gas reservoirs shows strong relevance with the natural gas components and has an obvious impact on reservoir types and their petrophysical properties. In this work, core and fluid samples were collected from the Right Bank of Amu Darya reservoirs, Turkmenistan. Then, fluid composition analysis and flash evaporation experiments were performed to investigate the components of reservoir fluid. Petrophysical properties, that is, porosity and permeability, and micropore structures of cores were determined by permeameter–porosimeter and scanning electron microscope (SEM) analysis, respectively. Results in this work indicate that the H2S content shows obvious relevance to fluid components in carbonate gas reservoirs. With the increase of H2S content, the total heavy hydrocarbons and potential condensate content decrease, while the condensate density increases. In addition, at higher H2S content, larger pore and vug porosity was observed. However, in reservoirs with lower H2S content, the matrix pores are relatively tight and prone to develop fractures. Furthermore, sulfate thermochemical reduction (TSR) is found to be the dominant contributor to high H2S content in carbonate reservoirs through material and thermodynamic condition analysis. The Gibbs free energy and normalized hydrocarbon content show that the consumption of heavy hydrocarbons generally increases with carbon numbers during TSR, but reaches a minimum at the components of C7 to C9. Finally, the relationship between TSR and rock petrophysical properties was discussed, indicating that pore volume enlargement and the dissolution effect of acidic gases are the main mechanisms for TSR to improve carbonate reservoir property. Results in this study present comprehensive analyses of the links between H2S content and fluid components and petrophysical properties in carbonate gas reservoirs.

Riverbed processes in the lower reaches of the Amu Darya river in conditions of anthropogenic impact on the river flow

The interaction of the river flow with bottom riverine forms is considered under the significant influence of anthropogenic factors leading to changes in the water regime, the riverbed process and the ecology of watercourses. The section under consideration in the lower reaches of the Amu Darya River, taking into account the nature of the influence of both hydroelectric units, is divided into three parts: the upper section – from the Tuyamuyun hydroelectric unit to the Kipchak gorge; the middle section – from the Kipchak gorge to the Takhiatash hydroelectric unit; the lower section – from the Nietbaytas hydropost to the Kyzyljar hydropost (the delta part of the Amu Darya River). The regularities of the negative impact of anthropogenic factors on the hydraulic regime and the course of riverbed processes have been studied at these sites. The scale of the impact of anthropogenic factors significantly altering the course of the riverbed process has been determined and a generalized indicator characterizing the complex of various anthropogenic loads has been developed. It shows the change in water and riverbed regimes under the influence of hydraulic engineering measures in recent years in the lower reaches of the Amu Darya River, which are still observed in the case of wandering of the stream and the occurrence of peculiar currents, as well as deigish, where the banks are not protected by structures. In places where damless water intakes are located in channels, due to the large width of the river, planned instability occurs, which complicates water supply. According to the results of the analysis of the mechanism of these phenomena, appropriate measures have been developed to improve water intakes.