The cityscapes of European capital cities     

Herman van der Wusten 《GeoJournal》2000,51(1-2):129-133

Capital cities are politico-administrative centers. They are command centers, they symbolize authority and also the unit that is governed. Primarily they are capitals of states, but other governance systems may also have capitals. In the European context there are now regional capital cities and at least the concept of a European capital. Particularly on account of their symbolic function but also for the uses made of its appearance in political life, the cityscape of capital cities is an interesting topic for research. There are different types of capital cities in Europe that give rise to different cityscapes. Existing urban networks and types of political regime are important in this respect. Although cityscapes are pretty stable, they are differently perceived over time and uses made of them also change. A research agenda for this intersection of historical, cultural and political geography should concentrate on the evolution of these cityscapes, their perception and the uses made of them in the acting out of politics.  相似文献   

辽东湾红沿河附近海域2017—2018年冬季气温-水温-冰情关系研究     

马玉贤  王玉  於凡  许宁  袁帅  史文奇 《冰川冻土》2022,44(5):1482-1491

辽东湾是我国冰情最严重海域,每年冬季都会受到海冰的显著影响,冰情预测评估可为辽东湾涉海活动提供防冰抗冰的技术依据。建立气温-水温-冰情的相关性,结合便于获取的现场高精度连续气象数据和高精度冰情预测模型,可实现局地小尺度的冰情快速预测评估。基于2017—2018年冬季辽东湾东岸红沿河附近海域实测气象-水温-冰情同步观测数据,结合辽东湾大尺度整体冰情（浮冰面积）,推演局地气温、水温与不同尺度冰情评价参数（浮冰范围与冰厚）的相关关系,提出基于不同气温区间的气温变化规律的冰底热通量选取方法,进而建立适用于辽东湾的气温-水温-冰情评估方法。相关性分析结果显示：观测点气温与水温存在明显相关性;浮冰范围与气象数据存在明显相关性,临界温度为 -5 ℃的累计负气温能很好拟合本年度盛冰期浮冰范围。基于HIGHTSI进行数值模拟后发现：水温与块体积法计算冰底热通量时,冰水间的热传递系数取2.2×10^-5是可行的;水温对冰情的影响表现在海冰冰厚最大值与冰期长短。为弥补辽东湾其他海域因缺少实测海水温度观测数据欠缺、冰底热通量选取不准选取导致的冰情模拟预测评估困难的问题,本文依据水温与气温的相关性,将水温随气温变化划分为结冰区（气温小于-10 ℃时水温维持冰点附近）、过渡区（气温为-10~-5 ℃时水温处于-1.4~-0.4 ℃）、融冰区（气温高于-5 ℃时水温随气温的增大逐渐增大）,进而提出适用于辽东湾所有海域的冰底热通量计算方法和冰情评估方法。  相似文献   

大安市地下水动态变化趋势及驱动因素研究          下载免费PDF全文

张真真  卞建民  李天宇  高月 《水文》2015,35(4):91-96

为研究大安市地下水位的变化特征及其主要控制因素,根据大安市气候因素、引水灌溉水量、地下水开采和地下水埋深等数据资料,分析了环境因素的变化规律及趋势,基于suffer软件利用克里格方法对地下水埋深进行插值,分析其时空演变规律及驱动因素。结果表明,降水量呈波动增加的趋势,平均年降水量增量为0.249mm/a;蒸发量呈波动下降的趋势,平均年蒸发量增量为-2.063mm/a;引水灌溉水量呈增加趋势,平均年灌溉水量增量为0.212×108m/a。潜水埋深呈小幅度减小趋势,年均倾斜率为-0.023m/a,承压水埋深呈波动上升趋势,年均倾斜率为0.146m/a。承压水动态变化的驱动因子由大到小依次为人工开采(主要是农业开采与生活用水)、引水灌溉、降水、蒸发,农业开采是最主要的影响因子。研究结果可为制定完善的水资源调控方案提供理论依据。  相似文献   

川北山丘区地下水补给特征与定量研究          下载免费PDF全文

周志超  李杰彪  苏锐  郭永海  赵宏刚  王彦江  季瑞利  张明 《水文》2015,35(5):54-60

针对川北山丘区地下水资源和污染防护研究中地下水补给难以定量等问题,以川北典型山丘区平溪河北岸的山丘区子流域为研究对象,布设监测孔并对其地下水的水位和水温开展动态监测,并基于大气压监测数据校正地下水监测水位,分析了山丘区地下水水位及水温的年内动态变化特征;采用渗水试验和分段双栓塞水文地质试验获取含水层空间渗透系数;基于达西断面法定量计算了研究区内观测断面的地下水径流补给量,并建立了月降雨量与降水入渗系数的函数关系,结果显示:研究区多年平均大气降水入渗补给量为16.61mm,多年平均降水入渗系数为0.0182;月降雨量与降水入渗系数呈幂函数关系;此成果可为研究区地下水资源、地下水防污性能评价及地下水数值模拟等研究提供重要依据。  相似文献   

Non-state governance and climate policy: the fossil fuel divestment movement     

Julie Ayling  Neil Gunningham 《Climate Policy》2013,13(2):131-149

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Sectoral targets for developing countries: combining ‘common but differentiated re-sponsibilities’ with ‘meaningful participation’     

《Climate Policy》2013,13(1):731-751

Although a global cap-and-trade system is seen by many researchers as the most cost-efficient solution to reduce greenhouse gas (GHG) emissions, the governments of developing countries refuse to enter into such a system in the short term. Many scholars and stakeholders, including the European Commission, have thus proposed various types of commitments for developing countries that appear less stringent, such as sectoral approaches. A macroeconomic assessment of such a sectoral approach is provided for developing countries. Two policy scenarios in particular are assessed, in which developed countries continue with Kyoto-type absolute commitments, while developing countries adopt an emissions trading system limited to electricity generation and linked to developed countries' cap-and-trade systems. In the first scenario, CO₂ allowances are auctioned by the government, which distributes its revenues as a lump sum to households. In a second scenario, the auction revenues are used to reduce taxes on, or to give subsidies to, electricity generation. The quantitative analysis, conducted with a hybrid general equilibrium model, shows that such options provide almost as much emissions reduction as a global cap-and-trade system. Moreover, in the second sectoral scenario, GDP losses in developing countries are much lower than with a global cap-and-trade system, as is also the effect on the electricity price.  相似文献   

Comparative policy analysis: Neoliberalising New Zealand     

J. Richard Peet 《New Zealand geographer》2012,68(3):151-167

Comparative policy analysis involves systematically examining the long‐term formation of public policies across a number of societies. It focuses particularly on the sequence of policy regimes: liberalism – Keynesianism/social democracy – neoliberalism. Since 1980, neoliberalism has been widely adopted as the guiding ideological structure for economic policy making. But neoliberalism encounters resistances that vary with national contexts. New Zealand is a particularly interesting case because of its reputation as a social democratic, welfare state that went neoliberal with a vengeance (Rogernomics).  相似文献   

蚌埠闸及上游闸坝对淮河自然水文情势的影响   总被引：3，自引：0，他引：3  

胡巍巍 《地理科学》2012,(8):1013-1019

淮河流域建设了许多闸坝,为揭示如此密集的闸坝对河流自然水文情势的影响,选取比较典型的淮河干流上的蚌埠闸作为控制节点,用成熟的IHA法和RVA法,研究蚌埠闸及其上游闸坝对水文情势的影响程度,同时通过蚌埠水文站水文情势变化的估算来分析闸坝对淮河河流生态水文条件的影响。结果显示,这些闸坝对河流水文情势的影响强烈,特别是在枯水季节。由此得出的淮河蚌埠段生态水文目标可为蚌埠闸开展生态系统管理、生态修复以及进行生态调控提供理论支持。  相似文献   

Deformation during exhumation of medium‐ and high‐grade metamorphic rocks in the Variscan chain in northern Sardinia (Italy)     

Rodolfo Carosi  Chiara Frassi  Chiara Montomoli 《Geological Journal》2009,44(3):280-305

The Anglona and SW Gallura regions represent key places to investigate the tectonic evolution of medium‐ and high‐grade metamorphic rocks cropping out in northern Sardinia (Italy). From south to north we distinguish two different metamorphic complexes recording similar deformation histories but different metamorphic evolution: the Medium Grade Metamorphic Complex (MGMC) and the High Grade Metamorphic Complex (HGMC). After the initial collisional stage (D1 deformation phase), both complexes were affected by three contractional deformational phases (D2, D3 and D4) followed by later extensional tectonics. The D2 deformation phase was the most significant event producing an important deformation partitioning that produced localized shearing and folding domains at the boundary between the two metamorphic complexes. We highlight the presence of two previously undocumented systems of shear belts with different kinematics but analogous orientation in the axial zone of Sardinia. They became active at the boundary between the MGMC and HGMC from the beginning of D2. They formed a transpressive regime responsible for the exhumation of the medium‐ and high‐grade metamorphic rocks, and overall represent a change from orthogonal to orogen‐parallel tectonic transport. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

Effects of riverbed incision on the hydrology of the Vietnamese Mekong Delta     

Doan Van Binh  Sameh A. Kantoush  Tetsuya Sumi  Nguyen Phuong Mai  Trieu Anh Ngoc  La Vinh Trung  Tran Dang An 《水文研究》2021,35(2):e14030

The hydrogeomorphology of the Vietnamese Mekong Delta (VMD) has been significantly altered by natural and anthropogenic drivers. In this study, the spatiotemporal changes of the flow regime were examined by analysing the long-term daily, monthly, annual and extreme discharges and water levels from 1980 to 2018, supported by further investigation of the long-term annual sediment load (from the 1960s to 2015), river bathymetric data (in 1998, 2014 and 2017) and daily salinity concentration (from the 1990s to 2015) using various statistical methods and a coupled numerical model. Then, the effects of riverbed incision on the hydrology were investigated. The results show that the dry season discharge (i.e., in March–June) of the Tien River increased by up to 23% from the predam period (1980–1992) to the postdam period (1993–2018) but that the dry season water level at My Thuan decreased by up to −46%. The annual mean and monthly water levels in June at Tan Chau and in January and June–October at My Thuan in the Tien River decreased statistically, even though the respective discharges increased significantly. These decreased water levels instead of the increased discharges were attributed to the accelerated riverbed incision upstream from My Thuan, which increased by more than three times, from a mean rate of −0.16 m/year (−16.7 Mm³/year) in 1998–2014 to −0.5 m/year (−52.5 Mm³/year) in 2014–2017. This accelerated riverbed incision was likely caused by the reduction in the sediment load of the VMD (from 166.7 Mt/year in the predam period to 57.6 Mt/year in the postdam period) and increase in sand mining (from 3.9 Mm³ in 2012 to 13.43 Mm³ in 2018). Collectively, the decreased dry season water level in the Tien River is likely one of the main causes of the enhanced salinity intrusion.  相似文献