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1.
Although both the Caspian and Aral Sea basins are affected by fluctuations in the general moisture conditions affecting the Northern Hemisphere, the two drainage basins react differently to identical moisture changes both over the long term and over the short term. Over the short term, a shift in wet periods has been observed between the European part of the USSR, which contains the Volga basin draining into the Caspian, and western Asia, which contains the Aral Sea drainage basin. Since there is a direct relationship between general moisture conditions and level changes, the short-term level fluctuations would be heterochronous (out of phase) in the two seas. Over the long term, the comparison is complicated by the fact that Caspian drainage derives mainly from snow meltwater in the Russian plain while Aral Sea drainage derives from a combination of snow and glacier meltwater. Glacier runoff tends to increase in dry, warm periods and to decrease in wet, cold periods of glacier growth, while snow is related directly to general moisture conditions.  相似文献   

2.
The first of two papers on the problem of forecasting the level of the Caspian Sea evaluates factors widely believed to have been responsible for its lowering during much of the present century (including tectonic movements, climatic cycles, human activity). It concludes that previous forecasts have been inaccurate because of the failure to adequately model the complexity of processes involved, specifically the internal mechanisms of “self-regulation” of water levels. Continuation of the recent slight rise in the Caspian's level is predicted at least into the early 1990s (translated by Andrew R. Bond).  相似文献   

3.
The authors, questioning the implications for the Caspian of a conventional model of shoreline dynamics on a flat, sandy coast upon a rise in sea level, present the findings of field observations made along the Dagestan shore during the period (post-1977) of the recent rise of the Caspian Sea level. They argue that changes in coastal morphology have varied largely according to the steepness of the offshore slope and, in general, sharply accelerated erosion was observed only on more steeply sloping sections of coast and in areas previously protected by rock benches (translated by Jay K. Mitchell; PlanEcon, Inc.; Washington, DC 20005).  相似文献   

4.
In an effort to stabilize the declining level of the Caspian Sea, it has been proposed that evaporation from the water surface be reduced by decreasing the size of the sea through construction of a dam in the northern portion. Data on the geology and hydrology of the Caspian Sea bed suggest that the construction of a dam might have undesirable consequences not only for the northern fisheries basin but for the sea as a whole. The findings are based on the presence of salt domes on the bottom of the northern Caspian Sea. An influx of highly mineralized subsurface waters along faults associated with the salt domes as well as leaching of salt from the structures themselves may threaten to raise the salinity of the northern fisheries basin to intolerable magnitudes. The presence of a man-made dam, in the author's view, would also interfere with the natural circulation of water, threatening contamination of deeper layers of the Caspian Sea with hydrogen sulfide, as has happened in the case of the Black Sea. [For a discussion of the Caspian Sea problem, see Soviet Geography, November 1972.]  相似文献   

5.
Differences in available data on the area of the Caspian Sea are analyzed, and an effort is made to explain them. The differences are particularly pronounced in the shallower northern portion of the sea, where the drop of the sea level over the years has produced more significant changes in shoreline configuration. Greater use of space imagery is urged in determining changes in shoreline configuration, and the setting of “geographical standards” is proposed to avoid continuing confusion in published data. The technical problem of calculating the physical water area, including surface roughness produced by wave motion, is discussed.  相似文献   

6.
An analysis of evaporation changes in the Central Asian plain in connection with the drop of the Aral Sea level beginning in 1961 shows that there has been a reduction in evaporation from stream valleys and deltas and an increase in evaporation from irrigated land and newly formed evaporating surfaces. These new entities are primarily the Arnasay depression (west of the Golodnaya Steppe irrigation district) and the Sarykamysh depression (west of the lower reaches of the Amudarya), which have become filled with spent irrigation water draining from the irrigated land. Another new source of evaporation associated with human activity are the lakes and wetlands formed along the Kara Kum Canal as a result of the filtration of canal water. It turns out, furthermore, that irrigation on sloping piedomon plains, such as those watered by the Kara Kum Canal, requires more water than in old irrigated alluvial plains because of the additional water needed to flush salt out of the soil and to fill subsoil cavities and raise the watertable.  相似文献   

7.
The history of variations of the level of the Aral Sea from the most ancient times is reviewed and much useful information presented on natural regimes of the Aral's tributary rivers, the Amudar'ya and Syrdar'ya; the natural high- and low-water cycles of the Aral; and historical episodes where natural or human events diverted the Amudar'ya's flow westward into Lake Sarykamysh, which served as a kind of “alternative Aral” during these situations. Thus, the present decline of the Aral and growth of Sarykamysh can be viewed as just one cycle (albeit man-modified) of an Amudar'ya-Aral-Sarykamysh drainage system. Translated by Edward Torrey, Alexandria, VA 22308 from: Izvestiya Akademii Nauk SSSR, seriya geograficheskaya, 1990, No. 1, pp. 78-86.  相似文献   

8.
A specialist in loess geomorphology and arid-zone hydrology distinguishes three categories of factors accounting for waterlevel changes in the Aral Sea. She judges the most significant to be changes in inflow resulting from changes in the course of the Amudarya, the more important of the two tributary streams. The Amudarya at various times emptied into the Sarykamysh depression, southwest of the Aral Sea, giving rise to a flow of water through the now dry Uzboy channel to the Caspian Sea. Climatic change, involving alternations of wet and dry cycles, is said to have accounted for only minor water level fluctuations, of the order of 4 to 6 m, against the background of the major fluctuations produced by the Amudarya course migrations. Human activity, notably irrigation, is regarded as having become significant only in modern times as a result of an expansion of irrigation works. The present abrupt decline in the Aral waterlevel (6 m from 1960 to 1977, including 2 m in the last three years) is attributed to the combination of a dry climatic cycle and greatly increased use of water for irrigation.  相似文献   

9.
On the basis of new calculations of the loss of water through evaporation from the temporarily flooded litteral zone of the northeast Caspian and the possible savings in the water budget that might be achieved by partitioning off the northeast shoals, the authors conclude that little would be gained by any project designed to reduce the water area of the northern Caspian.  相似文献   

10.
11.
A large body of empirical data on the dynamics of local travel in the USSR is surveyed to illustrate the influence of commuter movement on the formation and spatial interaction of settlement systems. Correlations are established between commuting patterns and the population levels of cities of different size cateogries. (Translated by Marcia Levenson, University of California, Berkeley, CA 94720.)  相似文献   

12.
The article examines the prospects of using runoff characteristics and changes in runoff composition as a basis for predicting environmental modification. The technique is employed to assess changes in the circulation of matter that are taking place in the drainage basin of the Aral Sea as a result of the intensification of irrigation. Overall runoff, including its liquid, solid (suspended sediment) and chemical phases, is analyzed in connection with a shift in the deposition of material from the Aral Sea to the irrigated plains.  相似文献   

13.
In Tibetan areas, prior to the Democratic Reform (1959-1960), there were over 2,700 monasteries, and the population of monks and nuns totaled about 110,000, accounting for 10 percent of the total Tibetan population (1.2 million).  相似文献   

14.
刘丽丽  徐蕊 《人文地理》2010,25(4):77-81
自1978年始,为了发挥中心城市带动周围农村的作用,国家行政体制作出了重要改革,实行市领导县体制。随之各级行政区的数量、名称和范围发生了较大的变化。本文以1978-2007年国家民政部统计数字为准,对改革开放30年来,中国县级以上行政区域名称的变更进行了统计分析与研究,揭示了政区通名和专名的变更特点及影响因素,指出更名中存在的主要问题,最后提出县级以上行政区域名称的变更的对策和建议。  相似文献   

15.
16.
林李月  朱宇  柯文前 《人文地理》2021,36(1):125-134
基于2016年中国流动人口动态监测数据,构建多维度的市民化评估指标体系,测算和探究二代流动人口的市民化水平与影响因素.研究发现:①二代流动人口市民化水平总体偏低,并且不同维度发展各异且存在明显的区域差异.②二代流动人口市民化水平是由个体市民化能力与流入城市特征共同作用的结果,但影响就业状况和生活方式的因素集中在个体的人...  相似文献   

17.
Between 1975 and 1983 the Swedish labour movement discussed a proposal to establish wage earner funds that would gradually shift the ownership in medium to large companies from employers to workers. This article starts by shedding light on the genesis of the proposal in the 1960s and 1970s and the reactions it provoked in Swedish society. Focus then switches to how the Meidner plan was understood in Italy in a time of pronounced social conflict marked, on one hand, by the redefinition of the relationship between trade unions and politics and, on the other hand, by soaring opposition among the various trade unions and the growing distance between the two major leftist parties. These divisions reverberated on the ways the wage earner funds – in their various versions – were understood by the organizations of the Italian labour movement; the assessment of the plan's feasibility and its applicability to the Italian case came to reflect conflicting views on industrial and economic democracy and on the relationship between Nordic social-democracies and Italian reformism.  相似文献   

18.
试论环渤海物流网络的形成与运作   总被引:11,自引:2,他引:9  
在简述物流发展背景与研究现状的基础上,作者界定了物流网络的概念与研究地域的范围,并且分析了环渤海物流网络的构成。同时作者仔细探讨了环渤海物流网络的形成机制和运作模式,通过分析,作者认为网络轮廓-海陆地域形状、网络节点-城市、网络联线-运输通道、网络能量-区域经济和运作主体-物流企业等五个要素共同作用而形成了物流网络,其运作由运作模块、驱动模块和调控模块组成。最后作者提出了相应的发展对策。  相似文献   

19.
宁夏回族社区空间结构特征及其变迁   总被引:5,自引:0,他引:5  
陈忠祥 《人文地理》2000,15(5):39-42
本文论述了地理学研究社区的主体内容为:社区的空间结构及人地关系的变化对社区发展和社区建设的影响,重点探讨了宁夏回族农村和城市社区空间结构的基本特征,并对社区空间结构的变迁态势和变迁过程进行了理论和实证分析。  相似文献   

20.
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