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1.
Severe weather can have serious repercussions in the transport sector as a whole by increasing the number of accidents, injuries and other damage, as well as leading to highly increased travel times. This study, a component of the EU FP7 Project EWENT, delineates a Europe-wide climatology of adverse and extreme weather events that can be expected to affect the transport network. We first define and classify the relevant severe weather events by investigating the effects of hazardous conditions on different transportation modes and the infrastructure. Consideration is given to individual phenomena such as snowfall, heavy precipitation, heat waves, cold spells, wind gusts; a combined phenomenon, the blizzard, is also considered. The frequency of severe weather events, together with the changes in their spatial extension and intensity, is analyzed based on the E-OBS dataset (1971–2000) and the ERA-Interim reanalysis dataset (1989–2010). Northern Europe and the Alpine region are the areas most impacted by winter extremes, such as snowfall, cold spells and winter storms, the frequency of heavy snowfall. The frequency of hot days is highest in Southern Europe. Severe winds and blizzards are the most common over the Atlantic and along its shores. Although heavy rainfall may affect the whole continent on an annual basis, extreme precipitation events are relative sparse, affecting particularly the Alps and the Atlantic coastline. A European regionalization covering similar impacts on the transport network is performed.  相似文献   

2.
参数区域化方法是解决资料缺乏地区水文模拟和预报的有效手段,主要包括回归法、空间邻近法和属性相似法三类方法,可将有资料流域的水文模型参数移用到资料缺乏流域。首先回顾了区域化方法的基本原理和应用方法,并分析了三类主要区域化方法的适用性。从流域特征因子、水文模型及参数、不确定性探讨三个方面综述了区域化方法的研究进展。分析发现,当前区域化方法缺乏完善的理论基础,流域特征因子选择存在主观性,水文模型及参数的适用性方面研究不足。最后展望了未来的研究重点:(1)多维度适用性比较;(2)水文过程和参数的空间分布规律;(3)参数的尺度问题;(4)参数区域化的不确定性问题。  相似文献   

3.
The historical processes of industrialization and urbanization have caused a variety of urban patterns in the largest conurbation of Central Europe, the Ruhr region, that now has to pass a period of economic recession and stagnation.After an outline of the historical development the existing economic regionalization is enlarged by a system of subregional areas which is based on the various urban patterns of the region. This system shows striking coincidence with the present central place structure. Small scale population trends can be explained by and future planning objectives may be derived from it.  相似文献   

4.
The linguistic diversity in the European Union is generally viewed as an essential component of the European identity, but the linguistic regime of the EU institutions (with eleven official and working languages) is not undisputed. In addition, the upcoming enlargements will complicate greatly the continuation of the present practices as new Member States bring new official languages. As a result, the debate about possible reforms is likely to be boosted by the necessity to prepare EU institutions for further enlargment. The present regime of institutional multilingualism is criticised from different angles, resulting in three options for the future. In this paper the linguistic regime of EU institutions is discussed in relation to general ideas about the nature of this supranational political system. Supranationalism is treated here as a program to supersede nationalism. Three variants are distinguished: pacified nationalism, neo-nationalism and post-nationalism. The paper examines how these different visions of Europe shed different lights on the issue of multilingualism (in terms of communication, identity and power) and its institutionalisation in the linguistic regime of the core instituions of the European Union. Although the three models are compatible with several arrangements, they support or oppose them for different reasons. Besides, they differ regarding the significance of the linguistic regime of the EU institutions for the whole polity and their ability to steer linguistic practices.  相似文献   

5.
Phanerozoic metallogenesis in Europe displays divergent characteristics which may be related to the variable nature of the three great European Phanerozoic orogens: Caledonian, Variscan and Alpine. These reflect different geodynamic processes. The Caledonian orogen resulted from the interaction of essentially oceanic with continental lithosphere, whilst the Variscan and Alpine orogens evolved mainly from continent-continent collisions with the involvement of a series of smaller oceanic basins. Each major stage of the orogenic processes is characterised by a typical metallogeny. The occurrence of subduction-related processes in the Caledonian orogeny gave rise to extensive VHMS deposition with characteristic Zn:Cu ratio signatures. The relative lack of abundance of metal-rich, Andean-type porphyry-type mineralisation remains unexplained, unless present erosional levels have prevented the preservation of such deposits. Continent-continent collisions do not appear to result in extensive mineralisation unless elevated heat flows result, possibly as a result of lithospheric delamination at the peak collisional stage. The development of late stage and peri-orogenic sedimentary basins are characterised by extensive Pb-Zn-Ba-F mineralisation as expressions of basinal fluid flow of regional dimensions.  相似文献   

6.
Europe has come to recognize that its regions have a major role to play in achieving its cohesion and competitiveness objectives. EU policies and Structural Fund principles are therefore increasingly geared towards enhancing regional capacities. Regions across Europe are responding, with varying results so far. The Randstad, in the Netherlands, presents itself as a ‘far from best’ example. Despite continued and serious attempts to strengthen capacities and institutions, the region still lacks effective governance. This paper explores the question why it is next to impossible to establish a framework for effective governance in the Randstad and distils some lessons for other regions in Europe.  相似文献   

7.
The deep thermal field in sedimentary basins can be affected by convection, conduction or both resulting from the structural inventory, physical properties of geological layers and physical processes taking place therein. For geothermal energy extraction, the controlling factors of the deep thermal field need to be understood to delineate favorable drill sites and exploitation compartments. We use geologically based 3-D finite element simulations to figure out the geologic controls on the thermal field of the geothermal research site Groß Schönebeck located in the E part of the North German Basin. Its target reservoir consists of Permian Rotliegend clastics that compose the lower part of a succession of Late Carboniferous to Cenozoic sediments, subdivided into several aquifers and aquicludes. The sedimentary succession includes a layer of mobilized Upper Permian Zechstein salt which plays a special role for the thermal field due to its high thermal conductivity. Furthermore, the salt is impermeable and due to its rheology decouples the fault systems in the suprasalt units from subsalt layers. Conductive and coupled fluid and heat transport simulations are carried out to assess the relative impact of different heat transfer mechanisms on the temperature distribution. The measured temperatures in 7 wells are used for model validation and show a better fit with models considering fluid and heat transport than with a purely conductive model. Our results suggest that advective and convective heat transport are important heat transfer processes in the suprasalt sediments. In contrast, thermal conduction mainly controls the subsalt layers. With a third simulation, we investigate the influence of a major permeable and of three impermeable faults dissecting the subsalt target reservoir and compare the results to the coupled model where no faults are integrated. The permeable fault may have a local, strong impact on the thermal, pressure and velocity fields whereas the impermeable faults only cause deviations of the pressure field.  相似文献   

8.
Alpha Mound and Beta Mound are two cold‐water coral mounds, located on the Pen Duick Escarpment in the Gulf of Cadiz amidst the El Arraiche mud volcano field where focused fluid seepage occurs. Despite the proximity of Alpha Mound and Beta Mound, both mounds differ in their assemblage of authigenic minerals. Alpha Mound features dolomite, framboidal pyrite and gypsum, whereas Beta Mound contains a barite layer and predominantly euhedral pyrite. The diagenetic alteration of the sedimentary record of both mounds is strongly influenced by biogeochemical processes occurring at shallow sulphate methane transition zones. The combined sedimentological, petrographic and isotopic analyses of early diagenetic features in gravity cores from Alpha Mound and Beta Mound indicate that the contrast in mineral assemblages between these mounds is caused by differences in fluid and methane fluxes. Alpha Mound appears to be affected by strong fluctuations in the fluid flow, causing shifts in redox boundaries, whereas Beta Mound seems to be a less dynamic system. To a large extent, the diagenetic regimes within cold‐water coral mounds on the Pen Duick Escarpment appear to be controlled by fluid and methane fluxes deriving from layers underlying the mounds and forcings like pressure gradients caused by bottom current. However, it also becomes evident that authigenic mineral assemblages are not only very sensitive recorders of the diagenetic history of specific cold‐water coral mounds, but also affect diagenetic processes in turn. Dissolution of aragonite, lithification by precipitation of authigenic minerals and subsequent brecciation of these lithified layers may also exert a control on the advective and diffusive fluid flow within these mounds, providing a feedback mechanism on subsequent diagenetic processes.  相似文献   

9.
Multi-phase flow in fractured rocks plays an important role in any hydrocarbon recovery process, be it for environmental remediation or natural oil and gas extraction. Fractures may form the primary production conduits, and the mass transport at the fracture interfaces with the matrix determines the effectiveness of extraction processes. This paper presents specific evidence for a relationship between fracture apertures and the porosity of the adjoining perpendicular layers in Berea sandstone samples. Measurements of fracture apertures were done with high-resolution Micro-Computed Tomography (MCT) with a voxel resolution of about 0.05 mm in three dimensions. Multi-phase fluid flow experiments were done using a medical CT scanner with a voxel resolution of about 1.00 × 0.25 × 0.25 mm. MCT evidence shows a correlation between aperture and the porosity of the intersected layers. The comparison was made by generating two-dimensional maps of matrix porosity and CT values adjacent to the fracture and of the corresponding fracture apertures. High-porosity layers are lined up with large fracture apertures. Multi-phase fluid experiments provided hydraulic evidence that the high-porosity layers have high permeability. Oil injection into a water-saturated sample was tracked by a sequence of transverse scans near the downstream tip of a fracture. The hydraulic evidence from the two-phase flow experiments also confirms high permeability in fracture strips adjacent to high-porosity and high-permeability layers. The reasons for the relationship between fracture aperture and the properties of the adjacent layers are not fully understood. Some explanation for the physical and hydraulic observations rests in the method of fracturing, fracture propagation, and the lithological characteristics of the rock.  相似文献   

10.
灰色聚类分析在地质灾害综合区划中的应用   总被引:2,自引:0,他引:2  
地质灾害作为一种主要的自然灾害,其综合区划研究成为当前学术界重要的前沿课题。利用灰色聚类分析的相关理论,在确立评价指标体系原则及要求的基础上,建立基于区域多源信息融合的地质灾害综合评价指标体系和评价模型,对陕西铜川地区的区域灾害程度进行了定量评价并得到地质灾害的聚类区划图谱。该地区可划分为极重灾、重灾和中灾3大片区,所得结果与区域实际灾情基本吻合。研究表明,灰色聚类分析的数学模型可以实现区域地质灾害的定量区划研究。   相似文献   

11.
The discovery of sites preserving tephra layers from multiple volcanic centres is key to constructing a single European tephrostratigraphic framework for the Late Quaternary. Until now, the tephrostratigraphy of Europe has been divided into two halves: sites in the North Atlantic and northern Europe regions link the Icelandic, Eifel, and the Massif Central volcanic histories; whilst sites in southern Europe record the sequence of tephra layers produced by circum-Mediterranean volcanic provinces. The missing link, able to tie together these two halves, is found in the tephrostratigraphic record of Lake Bled, Slovenia.Lake Bled, in the Julian Alps, Slovenia, holds a high resolution multi-proxy palaeoenvironmental archive for the Lateglacial of south-central Europe. Cryptotephra investigations have revealed three tephra layers: two closely spaced within Younger Dryas stadial sediments and one shortly after the start of the Bølling-Allerød interstadial warming. Two of the tephra layers (Bld_T120 and Bld_T240) are of Campanian origin and are correlated to deposits of the Pomici Principali (PP) and Neapolitan Yellow Tuff (NYT) eruptions, respectively. The third layer (Bld_T122) correlates to the Icelandic Vedde Ash (VA), extending the known fallout of this widespread marker layer farther to the southeast.The Lake Bled record also allows the stratigraphic relationship and relative ages of the VA and the PP eruption to be discerned for the first time. Whilst existing numerical age estimates for these two deposits are indistinguishable within errors, their close occurrence in the same lacustrine sediment sequence shows that the VA was erupted shortly prior to the PP eruption.The tephrostratigraphy of Lake Bled developed here helps us to tie together regional volcanic stratigraphies into a broader, continental-scale lattice of sites, with the potential to allow the transfer of dates between remote sequences and the construction of relative chronologies, beneficial in particular for environmental and archaeological research.  相似文献   

12.
Three distal tephra layers or cryptotephras have been detected within a sedimentary sequence from the Netherlands that spans the last glacial-interglacial transition. Geochemical analyses identify one as the Vedde Ash, which represents the southernmost discovery of this mid-Younger Dryas tephra so far. This tephra was found as a distinct horizon in three different cores sampled within the basin. The remaining two tephras have not been geochemically 'fingerprinted', partly due to low concentrations and uneven distributions of shards within the sequences sampled. Nevertheless, there is the potential for tracing these tephra layers throughout the Netherlands and into other parts of continental Europe. Accordingly, the possibilities for precise correlation of Dutch palaeoenvironmental records with other continental, marine and ice-core records from the North Atlantic region are highlighted.  相似文献   

13.
流体是地球各圈层之间相互作用的纽带,在成岩、成矿过程中起着十分重要的作用。目前,流体的研究主要集中在流体对先存矿物岩石进行的交代作用方面,而对流体直接结晶形成的矿物领域研究较少。文中根据作者近几年的研究成果对从流体直接结晶而成的矿物——流体晶以及流体晶矿物组合、流体岩等的定义、特征进行了归纳总结。最新的研究结果显示:岩浆中可以含有大量的流体,这些流体来源既可以是岩浆演化富集、岩浆与围岩相互作用产生,亦可以是外部来源。因此,流体晶矿物、流体岩在自然界应该是普遍存在的。流体晶矿物的提出将深化人们对地质过程的理解,发展岩石学及矿床学的研究新领域,有利于矿床勘探和成矿预测。  相似文献   

14.
GIS技术在地质灾害区划中的应用   总被引:13,自引:2,他引:13       下载免费PDF全文
岫岩县是辽宁省东部山地地质灾害最为典型的地区,存在以崩塌、滑坡、泥石流为主的多种地质灾害。本文应用大量野外地质灾害调查所收集的各种资料,建立Access数据库,并在GIS软件平台上运用投影转换功能,将数据库文件转换为具有属性的图形文件,并得到地质灾害分布图;将研究区进行网格剖分后,对已矢量化的各图层及灾害点文件叠加运算,得到灾害易发程度分区图、等值线图。分区的结果揭示了地质灾害空间分布特征及其与地质环境和人类活动的关系。  相似文献   

15.
《Geochimica et cosmochimica acta》1999,63(19-20):3145-3152
The adsorption of organic molecules at mineral–fluid interfaces has a profound influence upon geochemical reaction and transport processes, yet little is known about the in situ structures or properties of organic layers at mineral–fluid interfaces. We describe an X-ray reflectivity study of stearate monolayers adsorbed at the calcite surface from methanolic solutions. Using these measurements we are able to determine important aspects of the in situ structure, bonding, adsorption, and growth mechanisms of stearate monolayers. The experimental approach demonstrated here can be applied widely in studying the interaction of organic molecules with mineral surfaces in aqueous systems.  相似文献   

16.
异常压力环境下流体活动及其油气运移主通道分析   总被引:12,自引:1,他引:11  
沉积盆地的油气生成、运移和成藏过程与盆地流体作用密切相关, 而异常压力环境下流体活动有其特殊性, 因而与之相关的油气运移和成藏也有其特殊性.对于异常压力体系(包括高压和低压)而言, 存在2类流体系统, 即半开放型和封闭型流体系统.前者由于封闭层的间歇开启导致流体幕式释放, 后者以封闭层内热对流作用为主.按照封闭层开启的成因机制可划分为3类, 即水力破裂或流体压裂型、断裂型、断-压双控型.封闭层的间歇开启构成异常压力环境下油气运移的主通道.这些流体活动和油气运移在海底以及盆地的浅层和深层显示不同地球物理特征, 如气苗、麻坑、气烟囱和流体底辟带等.同样, 还可以利用岩石中残留的一些标记或异常现象示踪盆地流体活动, 如流体包裹体、地层水化学、有机地球化学异常、成岩作用异常、流体场动态模拟等.这些特征和标志为流体和油气运移主通道的识别, 同时也为异常压力环境下油气勘探提供重要的依据.   相似文献   

17.
This study illustrates a procedure conducive to a preliminary risk analysis of overpressure development in sedimentary basins characterized by alternating depositional events of sandstone and shale layers. The approach rests on two key elements: (1) forward modeling of fluid flow and compaction, and (2) application of a model-complexity reduction technique based on a generalized polynomial chaos expansion (gPCE). The forward model considers a one-dimensional vertical compaction processes. The gPCE model is then used in an inverse modeling context to obtain efficient model parameter estimation and uncertainty quantification. The methodology is applied to two field settings considered in previous literature works, i.e. the Venture Field (Scotian Shelf, Canada) and the Navarin Basin (Bering Sea, Alaska, USA), relying on available porosity and pressure information for model calibration. It is found that the best result is obtained when porosity and pressure data are considered jointly in the model calibration procedure. Uncertainty propagation from unknown input parameters to model outputs, such as pore pressure vertical distribution, is investigated and quantified. This modeling strategy enables one to quantify the relative importance of key phenomena governing the feedback between sediment compaction and fluid flow processes and driving the buildup of fluid overpressure in stratified sedimentary basins characterized by the presence of low-permeability layers. The results here illustrated (1) allow for diagnosis of the critical role played by the parameters of quantitative formulations linking porosity and permeability in compacted shales and (2) provide an explicit and detailed quantification of the effects of their uncertainty in field settings.  相似文献   

18.
Dušan Plut 《GeoJournal》2000,52(2):149-155
The state of the environment and environmental pressures in the EU Member States (EU15) and the Accession Countries (AC10) is discussed from the prospective of ecosystems and geopolitics. In the EU15, the reduction of the most acute kinds of pollution began in the 1970s, and at the beginning of the 1990s, an overall environmental development action program was made, aimed at sustainability. In the AC10, the state of the environment slightly improved in the 1990s, particularly thanks to the decline of industrial production and a general slump. Typical of the EU15 and the AC10 is the consumption of natural resources at an above-average level per inhabitant of the globe. The starting position in the EU15 with regard to a sustainable development is considerably more favourable than in the AC10.However, the EU15 are only in the phase of weak sustainability, with the emphasis laid on curative measures for eliminating some consequences of environmental pressures. To achieve the environmental and other goals of sustainable development of Europe and the planet, it is necessary to establish a strategic partnership on the basis of the equality of all European countries, to reduce radically the environmental pressures and consumption of natural resources per inhabitant, and to integrate the ecological principles into sectoral policies. The period of two-speed Europe should be as short as possible.  相似文献   

19.
河流功能区划方法及实例研究   总被引:1,自引:0,他引:1  
河流功能区划是规范和引导各类河流功能开发利用行为的基础工作。按照中国河流功能属性特点并考虑流域管理的需求,分析了河流功能区划的理论依据和区划原则,构建了由属性层、区划层、指标层和管理层4个层面构成的河流功能区划体系,给出了河流功能区的区划方法和具体的操作步骤。以太浦河为例进行了河流功能区划实例研究,提出了太浦河河流功能区划成果及其管理目标与对策。结果表明,提出的河流功能区划的方法是合理、可行的,能够为河流管理提供一个新途径。  相似文献   

20.
Fluid activity ratios calculated between millimeter- to centimeter-scale layers in banded mafic eclogites from the Tauern Window, Austria, indicate that variations in a H 2 O existed between layers during equilibration at P approximately equal to 2GPa and T approximately equal to 625°C, whereas a CO 2 was nearly constant between the same layers. Model calculations in the system H2O–CO2–NaCl show that these results are consistent with the existence of different saturated saline brines, carbonic fluids, or immiscible pairs of both in different layers. The data cannot be explained by the exisience of water-rich fluids in all layers. The model fluid compositions agree with fluid inclusion compositions from eclogite-stage veins and segregations that contain (1) saline brines (up to 39 equivalent wt. % NaCl) with up to six silicate, oxide, and carbonate daughter phases, and (2) carbonic fluids. The formation of crystalline segregations from fluid-filled pockets or hydrofractures indicates high fluid pressures at 2 GPa; the record of fluid variability in the banded eclogite host rocks, however, implies that fluid transport was limited to local flow along individual layers and that there was no large-scale mixing of fluids during devolatilization at depths of 60–70 km. The lack of evidence for fluid mixing may, in part, reflect variations in wetting behavior of fluids of different composition; nonwetting fluids (water-rich or carbonic) would be confined to intergranular pore spaces and would be essentially immobile, whereas wetting fluids (saline brines) could migrate more easily along an interconnected fluid network. The heterogeneous distribution of chemically distinct fluids may influence chemical transport processes during subduction by affecting mineral-fluid element partitioning and by altering the migration properties of the fluid phase(s) in the downgoing slab.  相似文献   

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