Science, développement et modernisation à l’époque brejnévienne : aménagement et gestion de l’eau dans le bassin du lac Balhaš

Zhang

Nurtazin

2018

Water

Central Asia's Ili River is fed by mountain streams that flow down into an isolated and arid basin that today is shared by Kazakhstan and China. Agriculture in the basin is dependent upon irrigation, which was practiced as long ago as the Iron Age, when early pastoralists constructed ditches to channel water from streams onto nearby fields. Irrigation had become much more common by the 18th century, when the region was controlled by the Dzungarian Khanate. The khanate was toppled by the Qing Chinese in the 1750s in the first of a series of confrontations that destroyed and then rebuilt the basin's agricultural economy. The region has since been dominated by a succession of Chinese and Russian (and later Soviet and independent Kazakh) governments, each of which recognized the essential role of irrigated agriculture in maintaining control. Thus every cycle of destruction led to reclamation of new lands, resettlement of farmers and upgrading of infrastructure to expand irrigation. This allowed an impressive diversity of fruits, vegetables and field crops to be grown, especially on loess soils of the more fertile upper basin, where tributaries could be easily tapped by gravity flow. Many of these tributaries were entirely diverted by the 19th century, so that they no longer reached the Ili. Large scale irrigation commenced in the 1960s, when the Soviets built Kapchagai dam and reservoir in the lower part of the basin and installed pumps to raise water from the Ili River onto nearby reclaimed sierozem soils, mostly for cultivation of rice. China later constructed a cluster of small-and medium-sized dams that enabled expansion of agriculture in the upper part of the basin. Many irrigated areas along the lower reaches of the Ili in Kazakhstan have been abandoned, but irrigation in the upper basin continues to expand. Declining soil fertility, salinization, pollution, insufficient inflows and adverse economic conditions currently challenge irrigation across the entire basin. Investments are being made in new technologies as a means to sustain irrigated agriculture in the basin, but it remains to be seen if these strategies will be successful.

Section: Russia and The Soviet Unionmentioning

confidence: 99%

Section: Russia and The Soviet Unionmentioning

confidence: 99%

Irrigation in the Ili River Basin of Central Asia: From Ditches to Dams and Diversion

Zhang

Nurtazin

2018

Water

“…Additional land cover types include water, wetland, tree cover, bare land, snow and ice, and urban areas. Lake Balkhash, an important source of fish for human consumption (Petr 1992, Timirkhanov et al 2010, Sadyrbaeva 2013, Graham et al 2017, and Kapchagai Reservoir, constructed by the Soviets in the late 1960s for both hydropower and irrigation (Chida 2013), represent the most conspicuous aquatic features of the basin. The city of Almaty, Kazakhstan, is the most visible urban area (figures 1, 3).…”

Section: Changes In Lulc Between 1995 and 2015mentioning

confidence: 99%

Changes in land use/land cover and net primary productivity in the transboundary Ili-Balkhash basin of Central Asia, 1995–2015

Shen

et al. 2019

Environ. Res. Commun.

Using remotely sensed data, we documented changes in land use/land cover (LULC) from 1995 to 2015 and net primary productivity (NPP) from 2000 to 2014 in Central Asia's 415,048 km 2 Ili-Balkhash Basin (IBB). This basin, which is shared by China and Kazakhstan, is in the midst of significant socioeconomic transformation due to the collapse of the Soviet Union, the emergence of Kazakhstan, and the economic rise of China. Grazing land covered 82.4% of the IBB in 1995; water bodies and bare land were the only other LULC categories occupying more than 3% of the basin's area. Changes in LULC were most evident on the Chinese side of the border, where crop production areas increased and grazing areas decreased between 1995 and 2015. The area of irrigated cropland in China grew by nearly 30%, primarily in the upper Tekes River valley and along the Ili River near the border with Kazakhstan. In contrast, the irrigated lands in Kazakhstan shifted geographically during this period, but the extent did not change. Expansion of wetlands and permanent water bodies, which occupied 2.1 to 2.9% and 4.6 to 4.7%, respectively, of the IBB in 1995 and 2015, was associated with accretion of Lake Balkhash and Kapchagai Reservoir in Kazakhstan and the construction of new reservoirs in China. NPP of the basin approached 700 g C m −2 /year in a few areas but was generally less than half this level and characterized by a declining trend except in highly productive irrigated areas of dense, stable vegetation. NPP decreases of more than −10 g C m −2 /year were apparent in mountainous and upland areas, as well as broad band of grassland and cropland in Kazakhstan. Areas surrounding Lake Balkhash were characterized by unstable to moderately stable, often sparse vegetation.

“…The river is interrupted by one major dam at Kapchagay in eastern Kazakhstan and by several smaller dams along its headwaters in China. Kapchagay dam and reservoir, which were installed by the Soviets in the late 1960s, were designed to generate about 300 megawatts of power and simultaneously enable irrigation of arid lands downstream and near the reservoir, primarily for rice [58]. The extent of irrigation from Kapchagay never reached expectations and, following a familiar pattern, declined substantially after the disappearance of the Soviet Union.…”

Section: Observations From the Ili River And Lake Balkhashmentioning

confidence: 99%

“…This was conditioned in part by changes in water flow characteristics and food availability as the impoundment filled, but other long-term factors were also at play. These include fishing pressure upstream [39], diversion of ever more upstream water for hydroelectric and irrigation projects in China [58,59], as well as climate change [17,62]. The latter driver is of particular importance.…”

Section: Observations From the Ili River And Lake Balkhashmentioning

confidence: 99%

The Current Status and Future of Central Asia’s Fish and Fisheries: Confronting a Wicked Problem

Graham

Uderbayev

2017

Water

Central Asia's arid lowland ecosystems are dependent on water that originates in nearby mountains and is carried by rivers to terminal lakes and freshwater seas with no outlets to the ocean. Fish traditionally thrived in these waterways, but they have become increasingly jeopardized by water impoundment and diversion for energy and crop production. Fish capture in the five new Central Asian republics consequently entered a period of long decline, a trend that was accelerated by removal of the centralized controls imposed by the former Soviet Union. Production levels have recovered during the past decade, but only in some countries. A similar trend is evident with aquaculture, which reached its lowest production levels in 2003-2008 but now is partially recovering. In both cases, progress is most evident in water-deficient Uzbekistan. Fish capture in Kazakhstan's Ili River ecosystem, including Kapchagay Reservoir and Lake Balkhash, is now dropping precipitously. Effects on the lake's fisheries have been magnified by the disproportionate rates of disappearance of valuable carp and pike-perch. The interrelationships between water, energy, and food underlie these threats to Central Asia's fish and define a classic "wicked problem" that must be addressed regionally with explicit attention given to fish as important components of the ecosystem. Recent developments, although not all positive, give reason for cautious optimism that the region's fisheries and aquaculture industries can be stabilized.