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61.
62.
采用层次分析法与熵权法相结合的方法,构建长株潭城市群城镇化综合发展水平和水资源开发利用综合潜力评价指标体系及响应关系模型,对2001-2015年间研究区域城镇化发展进程与水资源利用之间的动态过程进行定量研究,分析主要影响因素、变化特征以及两者响应特征。结果表明:长株潭城市群处于快速城镇化和规模扩张阶段,人口城镇化和空间城镇化水平高于经济城镇化和社会城镇化水平,城镇化发展质量有待提升;区域用水负荷逐年增加,虽然水资源利用效率和管理水平稳步提升,但水资源自然禀赋和开发利用程度受区域水文条件的影响显著。在2001、2005、2007、2009、2011年,长株潭区域城镇化的发展在一定程度上受到水资源系统的约束。协调好城镇化与水资源之间的关系,必须改变规模外延扩张模式,以控制水资源总量、有效提高水资源利用效率为目标,减弱水资源系统对城镇化发展的制约,提高水资源保障能力。  相似文献   
63.
Foundation deposits underneath the walls of two temples near Semna, Sudan (c. 1500-1480 BC), included dried plant material. Five fruit species are represented: Vitis vinifera (grape), Ficus carica (fig), Citrullus vulgaris (water melon), Phoenix dactylifera (date) and Ziziphus spina-christi. Of particular interest are the remains of tubers of Cyperus esculentus. The plants mentioned above are known as funeral gifts in Egyptian tombs.  相似文献   
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This paper investigates the critical role of workers to enhance the resilience of water supply services in cities at war through analyzing the case of Madrid and the Madrid water company Canales del Lozoya during the Spanish Civil War (1936–1939). We argue that securing the protection of vital urban flows mediated through infrastructures is a key objective of cities under attack. In doing so we contend that examining how those affected by the interruption of these flows cope with the situation represents a valuable but largely neglected form of water management. We illustrate how quotidian knowledge about the urban geography of water flows may have important repercussions for the war effort itself. In a nutshell, the case of Madrid offers an early account of the critical role of water workers in sustaining “urban ecologies under fire” securing the complex urban metabolism while also contributing to the struggle against invading forces.  相似文献   
66.
At Ocean Drilling Program Site 997 in Blake Ridge gas‐hydrate field in West Atlantic, pore‐water studies revealed a pronounced downward depletion of the heavy chlorine isotope to nearly ?4‰δ37Cl at approximately 750 m below sea floor (mbsf) associated with a 10% downward chlorinity decrease. This is one of the stronger 37Cl depletions hitherto reported for marine pore waters. Chlorinity reductions in hydrate‐bearing sediments commonly result from fresh‐water release by hydrate melting. However, in situ measurements at Site 997 suggest that >50% of the chlorinity reduction occurred prior to hydrate dissociation. Modeling the chlorinity profile shows that advection of a strongly 37Cl‐depleted, low‐chlorinity water (506 mm ) from below the drilled sequence can explain the reduction prior to sampling. Fitting the model to the δ37Cl curve yielded an advection rate of 0.18 mm year?1. Diffusive mixing with near‐0‰‐δ37Cl paleo‐seawater with maximum chlorinity at shallow subsurface depths (561 mm at approximately 20 mbsf) produced the smooth, steady trend. Separating that part of the freshening caused by advection and diffusion from that due to hydrate dissociation allowed estimation of average hydrate concentrations of 3.8% of the pore space (up to 24.5% in hydrate‐rich layers; near‐100% in rare massive hydrate layers). The deep‐seated source of the 37Cl‐depleted, low‐chlorinity water remains unknown and might be located below the sedimentary section in the oceanic basement.  相似文献   
67.
The skeletal remains uncovered from the 2nd and 3rd century underground tombs of Palmyra, Syria, retain traces of arthritis and mottled enamel. A brown discoloration was also observed in the teeth. In order to clarify that these facts can be related to fluorosis, the teeth excavated from Tomb C and F in the Southeast Necropolis were analyzed. The fluoride contents of the fluorosis-suspected teeth (0.56 ± 0.16% (n = 7)) were higher than those of normal teeth (0.16 ± 0.18% (n = 7)). The highest content (0.85%) proved that 22% of the hydroxide in apatite was substituted by fluoride. The fluoride concentrations of the natural water including deep well water available today in this area ranged from 0.3 to 3.0 mg l−1. The highest fluoride concentration was found to be regulated by the dissolution equilibrium of fluorite, CaF2, through the process of evaporation and concentration in this arid region. Because of the common ion effect by calcium ions in a high concentration, the fluoride concentration was lower than that expected from the solubility product of fluorite (8.2 mg l−1). The mechanism of this process has probably remained unchanged since ancient times and therefore the drinking water used by the ancient people of Palmyra was estimated to contain fluoride at a level causing fluorosis.  相似文献   
68.
The interactions of nature and society are intimately reflected in the degradation of the vast, yet diverse, landscapes and ecosystems of arid western China. The development of agriculture, especially irrigation, has altered rivers, soils and ecosystems so much that major ecological rehabilitation and restoration efforts have been needed since 1950. The catchments of the Tarim River in southern Xinjiang (the Tarim Basin) and of the Black River (Hei He) in Gansu Province and western Inner Mongolia provide examples of the benefits, difficulties and conflicts involved in dryland water management. In the early stages of the human development of these catchments, agriculture depending on irrigation using water from these inland rivers was encouraged. The over‐exploitation of these water resources led to such ecological problems as desiccation of lakes, drying out of rivers, degradation of soils and vegetation and lowering of groundwater levels, with consequent environmental and economic impacts. Since 1990 several high‐cost, national projects to re‐establish ecosystems have been initiated. Water is now released from dams in the headwaters of the rivers in order to restore water flows to the dried out lake basins. Such schemes have inevitably led to social problems and difficulties for the people who depended on the water from the dams for local irrigation. The contrasts in adjustments and attitudes over the use of water for agriculture and other economic activities, as opposed to schemes of restoration of ecosystems and ecological engineering, stem largely from two issues; inconsistent provision of information from the scientific community, and differing ideologies, namely environmental protection versus economic development.  相似文献   
69.
This paper examines the political and corporate constructions of the 1995–96 drought crisis in West Yorkshire, when an unprecedented public furore was provoked by the threat of water-supply cut-offs. A key outcome of this process was a profound crisis of confidence over the governance of water resources, which can be linked to the privatization of the industry and, more broadly, to the processes of redrawing the boundaries of the state. The water industry illustrates the contestability of neoliberal reforms seeking to inspire market-led growth with minimal government intervention. In particular, political dogma about the anticipated benefits of market competitiveness failed adequately to take into account public concern for the 'common good'.  相似文献   
70.
白鹤梁题刻保护问题及其与水域环境的关系   总被引:1,自引:0,他引:1       下载免费PDF全文
白鹤梁题刻是三峡库区唯一的国家级文物保护单位,受三峡水库淹没影响。在简单介绍和评价白鹤题刻现有保护方案的基础上,本文旨在探讨白鹤梁题刻及其与水域环境的相互关系,提出在进行白鹤梁题刻保护时,除了应注意保护白鹤梁题刻本身,还应恢复白鹤梁题刻赖以生存的水域环境及其所形成的独特的人文景观。  相似文献   
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