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Berlin is being remade as capital of a unified German nation state, just at the time when the role of nation states is being called into question by the claims of globalization, and the associated rise of global cities. The experience of Berlin suggests that it may be unhelpful to accept the world-city agenda as a universal template. Instead, it is necessary to explore the ways in which different agencies, companies and authorities negotiate the world around them, seeking to insert the city into pre-existing ideas and realities, as well as to influence and shape them, in what is best understood as a wider process of 'worlding'. 相似文献
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Bracken L. J. Oughton E. A. Donaldson A. Cook B. Forrester J. Spray C. Cinderby S. Passmore D. Bissett N. 《Natural Hazards》2016,82(2):217-240
River flooding is a serious hazard in the UK with interest driven by recent widespread events. This paper reviews different approaches to flood risk management and the borders (physical, conceptual and organisational) that are involved. The paper showcases a multi-method approach to negotiating flood risk management interventions. We address three fundamental issues around flood risk management: differences and similarities between a variety of approaches; how different approaches work across borders between professionals, lay people, organisations and between different planning regimes; and, whether the science evidence base is adequate to support different types of flood risk management. We explore these issues through a case study on the River Tweed using Q methodology, community mapping and focus groups, participatory GIS, and interviews, which enabled co-production of knowledge around possible interventions to manage flooding. Our research demonstrated that excellent networks of practice exist to make decisions about flood risk management in the Scottish–English borders. Physical and organisational borders were continually traversed in practice. There was an overwhelming desire from professional flood managers and local communities for an alternative to simply structural methods of flood management. People were keen to make use of the ability of catchments to store water, even if land needed to be sacrificed to do so. There was no difference in the desire to embrace natural flood management approaches between people with different roles in flood management, expertise, training or based in different locations. Thus conceptual borders were also crossed effectively in practice. 相似文献
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Geomorphological analyses of the morphology, lithostratigraphy and chronology of Holocene alluvial fills in a 2·75 km long piedmont reach of the wandering gravel‐bed River South Tyne at Lambley in Northumberland, northern England, have identified spatial and temporal patterns of late Holocene channel and floodplain development and elucidated the relationship between reach‐ and subreach‐scale channel transformation and terrace formation. Five terraced alluvial fills have been dated to periods sometime between c. 1400 BC –AD 1100, AD 1100–1300, AD 1300–1700, AD 1700–1850 and from AD 1850 to the present. Palaeochannel morphology and lithofacies architecture of alluvial deposits indicate that the past 3000 years has been characterized by episodic channel and floodplain change associated with development and subsequent recovery of subreach‐scale zones of instability which have been fixed in neither time nor space. Cartographic and photographic evidence spanning the past 130 years suggests channel transformation can be accomplished in as little as 50 years. The localized and episodic nature of fluvial adjustment at Lambley points to the operation of subreach‐scale controls of coarse sediment transfers. These include downstream propagation of sediment waves, as well as internal controls imposed by differing valley floor morphology, gradient and boundary materials. However, the preservation of correlated terrace levels indicates that major phases of floodplain construction and entrenchment have been superimposed over locally complex patterns of sediment transfer. Reach‐scale lateral and vertical channel adjustments at Lambley appear to be closely related to climatically driven changes in flood frequency and magnitude, with clusters of extreme floods being particularly important for accomplishing entrenchment and reconfiguring the pattern of localized instability zones. Confinement of flood flows by valley entrenchment, and contamination of catchment river courses by metal‐rich fine sediments following recent historic mining operations, have combined to render the South Tyne at Lambley increasingly sensitive to changes in flood regimes over the past 1000 years. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
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This paper illustrates the potential impact of future climate change on the archaeological resource of river catchments, specifically in Britain, but with reference to other examples across the globe, when considering issues of generic applicability. It highlights an area of the environmental record often neglected by policy makers and environmental planners when considering the impact of climate change; where cultural heritage has been considered in the past, an emphasis has been placed on the historic built environment and major monuments. Through studying the recent past, particularly the last 1,000 years, geomorphologists and geoarchaeologists can add much empirical data to these debates concerning system response. In addition to the impact of the changing intensity and pattern of natural geomorphic processes, human response to climate change ranging from new farming practices through to the implementation of mitigation strategies to minimise the effects of increased flood frequency and magnitude could be equally as damaging to the archaeological record if not managed through informed decision making. 相似文献
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M. G. Macklin D. G. Passmore A. C. Stevenson D. C. Cowley D. N. Edwards C. F. O'Brien 《第四纪科学杂志》1991,6(3):225-232
Archaeological survey and palaeoenvironmental investigations in Coe Burn, Callaly Moor, Northumberland, have examined the chronology and nature of prehistoric and historic land-use change in a small upland river catchment. These studies have revealed an intensively used landscape with evidence of late Neolithic to Bronze Age, medieval and post-medieval land use and settlement. Two episodes of valley floor alluviation are identified and dated to the middle-late Bronze Age and post-medieval periods. Magnetic mineral and geochemical analyses of fine sediments from the older alluvial fill show it to contain a high proportion of topsoil, which is believed to have been produced by soil erosion resulting from Bronze Age tree clearance and cultivation. Deposition of the younger alluvial fill (post AD 1500) was associated with the inwash of relatively unweathered bedrock generated by coal mining in the catchment. It is demonstrated that by integrating archaeological field survey with off-site palaeoenvironmental investigations a much fuller picture of human activity and land-use change has emerged than otherwise would have been the case. Studies of this type may be particularly useful in other upland river catchments where archaeological survival is limited or poor. 相似文献
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Textures in Partially Solidified Crystalline Nodules: a Window into the Pore Structure of Slowly Cooled Mafic Intrusions 总被引：2，自引：0，他引：2
Holness Marian B.; Anderson Alfred T.; Martin Victoria M.; Maclennan John; Passmore Emma; Schwindinger Kathleen 《Journal of Petrology》2007,48(7):1243-1264
Abundant glass is present along grain boundaries in coarse-grained,glass-bearing, crystalline gabbroic and peridotitic nodulesentrained and erupted in lavas from Iceland, Santorini and MaunaLoa (Hawaii), even when the total porosity is less than a fewvolume per cent. The glass films vary from a few microns toa few tens of microns thick, and are associated with stringsof small lensoid grain boundary pockets formed by impingementduring crystal growth. Additional porosity occurs as extensiveliquid-filled pockets adjacent to included grains within oikocrystsand as large triangular pockets formed by impingement of planar-sidedgrains. Interstitial material within glass films, and the irregularityof film thickness along a single grain boundary, suggest thatthe present pore structure is representative of the pore structurebefore entrainment and eruption. Pore geometry is consistentwith a dominant control by crystal growth during solidification,with little or no evidence for control by minimization of internalenergies driven by textural equilibration. Similarities betweenliquid distribution in the crystalline nodules and that of late-stage,interstitial phases in fully solidified mafic cumulates fromthe Rum and Skaergaard intrusions demonstrate that the crystallinenodules provide information about the latest stages of solidificationin slowly cooled mafic plutons. The highly permeable networkof intersecting liquid films, lenses and pockets may promotein situ crystallization in the solidifying mush, explainingthe common presence of adcumulates in such intrusions. KEY WORDS: textures; liquid distribution; mafic cumulates; crystalline nodules 相似文献
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