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401.
Paula K. Dunbar Kelly J. Stroker Vanita R. Brocko Jesse D. Varner Susan J. McLean Lisa A. Taylor Barry W. Eakins Kelly S. Carignan Robin R. Warnken 《Pure and Applied Geophysics》2008,165(11-12):2275-2291
In response to the 2004 Indian Ocean tsunami, the United States began a careful review and strengthening of its programs aimed at reducing the consequences of tsunamis. Several reports and calls to action were drafted, including the Tsunami Warning and Education Act (Public Law 109–424) signed into law by the President in December 2006. NOAA’s National Geophysical Data Center (NGDC) and co-located World Data Center for Geophysics and Marine Geology (WDC-GMG) maintain a national and international tsunami data archive that fulfills part of the P.L. 109-424. The NGDC/WDC-GMG long-term tsunami data archive has expanded from the original global historical event databases and damage photo collection, to include tsunami deposits, coastal water-level data, DART? buoy data, and high-resolution coastal DEMs. These data are used to validate models, provide guidance to warning centers, develop tsunami hazard assessments, and educate the public about the risks from tsunamis. In this paper we discuss current steps and future actions to be taken by NGDC/WDC-GMG to support tsunami hazard mitigation research, to ultimately help save lives and improve the resiliency of coastal communities. 相似文献
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403.
Accidental marine pollution can have major ecological and economic consequences at national and trans-national levels, and there is a need to achieve a better integration of science into actual decision-making systems to support prevention measures, response systems and management activities.. Effective linking mechanisms between R&D and end-users/policy stakeholders are required to ensure the relevance of R&D, effective uptake of R&D outputs, and suitable policy development. Different issues and barriers to effectively link accidental marine pollution R&D effort to end-users concerns and needs and to develop a trans-national strategic approach are identified, analysed, and further developed into recommendations. 相似文献
404.
Governors always have some image of what they are governing and why, and of what their role is. These images are often implicit. They are not reflected upon or discussed in the governance process, yet they have real consequences because they are acted upon. Interactive governance theory argues that image formation is an integral part of governance and that images are made as explicit as possible to avoid self-fulfilment. Such a process needs to be interactive and flexible to allow exploration of alternatives to existing governing images for the purpose of enhancing the governability of fisheries systems. In this paper, we contrast the classical image of the governing system (top down decision-making pyramid) and of the human-in-nature system (top down trophic pyramid) with alternative images (roses and inverted pyramid, respectively) and discuss the implication that these different images have on fisheries governance. 相似文献
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407.
Quintijn Clevis Gregory E. Tucker Gary Lock Stephen T. Lancaster Nicole Gasparini Arnaud Desitter Rafael L. Bras 《Geoarchaeology》2006,21(8):843-874
Fluvial processes have the potential to obscure, expose, or even destroy portions of the archaeological record. Floodplain aggradation can bury and hide archaeological features, whereas actively migrating channels can erode them. The archaeological record preserved in the subsurface of a fluvial system is potentially fragmented and is three‐dimensionally complex, especially when the system has been subjected to successive phases of alluviation and entrenchment. A simulation model is presented to gain insight into the threedimensional subsurface distribution, visibility, and preservation potential of the archaeological record in a meander‐floodplain system as a function of geomorphic history. Simulation results indicate that fluvial cut‐fill cycles can strongly influence the density of archaeological material in the subsurface. Thus, interpretation of floodplain habitation based solely upon features visible in the shallow subsurface (through traditional techniques such as aerial photography and geophysical prospection) can be misleading. In the examples, the loss of archaeological record by channel migration ranges between 45% and 90% over 12,000 years for channel belt‐dominated systems, decreasing to 10 to 30% for rivers where the floodplain width is a multiple of channel belt width. The modeling presented can be used to test excavation strategies in relation to hypothesized scenarios of stratigraphic evolution for archaeological sites. © 2006 Wiley Periodicals, Inc. 相似文献
408.
Robin L. McLachlan Andrea S. Ogston Nils E. Asp Aaron T. Fricke Charles A. Nittrouer Carlos A. F. Schettini 《Sedimentology》2020,67(7):3492-3512
Coastal barriers provide sheltered, low-energy settings for fine-grained sediment deposition and retention, although the process of back-barrier infilling and how tidal-channel connectivity impacts this process is not well-understood. Understanding how back-barrier environments infill and evolve is necessary to predict how they will respond to future changes in sea-level and sediment supply. With this motivation, in situ observations and sedimentary signatures from an Amazonian tidal-channel system are interpreted to create a conceptual model of morphological evolution in a macrotidal back-barrier environment that is rich in fine-grained sediment, vegetated by mangroves and incised by tidal channels with multiple outlets. Results indicate that within a high-connectivity back-barrier channel, tidal processes dominate sedimentation and morphological development. Sediment cores (<60 cm) exhibited millimetre-scale tidalites composed of sand and mud. High-connectivity channels allow tidal propagation from multiple inlets, and in this case, the converging flood waves promote delivery of sediment fluxing through the system to the mangrove flats in the convergence zone. Sediment preferentially deposits in regions with adequate accommodation space and dense vegetation, and in these zones, sediment grain size is slightly finer than that transiting through the system. The greatest sediment-accumulation rates (3 to 4 cm yr−1), calculated from steady-state 210Pb profiles, were found in the convergence zone near the mangrove-channel edge. As tidal flats aggrade vertically and prograde into the channels, accommodation space diminishes. In effect, the channel’s narrowest stretch is expected to migrate along the path of net-sediment flux towards regions with more accommodation space until it reaches the tidal-convergence zone. The location of recent preferential infilling is evidenced by relatively rapid sediment-accumulation rates, finer sediment and significant clustering of small secondary tidal channels. These findings shed light on how sediment transported through vegetated back-barrier environments is ultimately preserved and how evidence preserved in surface morphology and the geological record can be interpreted. 相似文献
409.
This paper contributes to the growing body of work on master planned estates in Australia by addressing the issue of the privatisation of assets and facilities, which in more conventional residential developments are in the public realm, owned and managed by local councils or other public bodies. The paper addresses the trend to place assets presented as lifestyle features, such as community and recreational facilities, open space or landscaping features, in a form of collective private ownership, known in Victoria as owners corporations. The provision of these facilities and assets for residents, however, has a number of implications relating to exclusivity, separation from the wider community, and potential conflicts within the master planned community itself. These issues are examined with reference to data gathered through an investigation of recently established master planned communities in the growth areas of Melbourne. 相似文献
410.
Long-term investment to drive the adoption of precautionary, adaptive and resilience-building fisheries management measures is urgently required, especially given the financially difficult transition period to reach sustainable fisheries. In this paper a case for investing in the recovery of large marine ecosystems is provided based on the future value of recovered fish stocks. It is argued that the current market-based sustainable seafood movement alone will not affect the scale of change needed and must be complemented by investment in fundamental conservation measures that will lead to the recovery of marine ecosystems and promote long-term sustainable use. A rationale for addressing the economically challenging transition period is provided and the basis of a new financial institution to finance the measures necessary for realising the economic, social and environmental benefits of large-scale fisheries reform is proposed. 相似文献