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991.
《Marine Policy》2017
Given competing objectives vying for space in the marine environment, the island of Bermuda may be an ideal candidate for comprehensive marine spatial planning (MSP). However, faced with other pressing issues, ocean management reform has not yet received significant traction from the government, a pattern seen in many locations. Spatial planning processes often struggle during the proposal, planning, or implementation phases due to stakeholder opposition and/or government wariness to change. Conflict among stakeholders about management reform has also proven to be a deterrent to MSP application in many locations. With these obstacles in mind, a detailed stakeholder survey was conducted in Bermuda to determine awareness, attitudes and perceptions regarding ocean health, threats to ocean environments, the effectiveness of current ocean management, and possible future changes to management. How perceptions vary for different types of stakeholders and how attitudes about specific concerns relate to attitudes about management changes were examined. Overall, the results indicate a high degree of support for spatial planning and ocean zoning and a high level of concordance even among stakeholder groups that are typically assumed to have conflicting agendas. However, attitudes were not entirely homogeneous, particularly when delving into details about specific management changes. For example, commercial fishers were generally less in favor, relative to other stakeholder groups, of increasing regulations on ocean uses with the notable exception of regulations for recreational fishing. Given the results of this survey, public support is likely to be high for government action focused on ocean management reform in Bermuda. 相似文献
992.
Rapid expansion of glacial lakes caused by climate and glacier retreat in the Central Himalayas 总被引:3,自引:0,他引:3
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Glacial lake outburst floods are among the most serious natural hazards in the Himalayas. Such floods are of high scientific and political importance because they exert trans‐boundary impacts on bordering countries. The preparation of an updated inventory of glacial lakes and the analysis of their evolution are an important first step in assessment of hazards from glacial lake outbursts. Here, we report the spatiotemporal developments of the glacial lakes in the Poiqu River basin, a trans‐boundary basin in the Central Himalayas, from 1976 to 2010 based on multi‐temporal Landsat images. Studied glacial lakes are classified as glacier‐fed lakes and non‐glacier‐fed lakes according to their hydrologic connection to glacial watersheds. A total of 119 glacial lakes larger than 0.01 km2 with an overall surface area of 20.22 km2 (±10.8%) were mapped in 2010, with glacier‐fed lakes being predominant in both number (69, 58.0%) and area (16.22 km2, 80.2%). We found that lakes connected to glacial watersheds (glacier‐fed lakes) significantly expanded (122.1%) from 1976 to 2010, whereas lakes not connected to glacial watersheds (non‐glacier‐fed lakes) remained stable (+2.8%) during the same period. This contrast can be attributed to the impact of glaciers. Retreating glaciers not only supply meltwater to lakes but also leave space for them to expand. Compared with other regions of the Hindu Kush Himalayas (HKH), the lake area per glacier area in the Poiqu River basin was the highest. This observation might be attributed to the different climate regimes and glacier status along the HKH. The results presented in this study confirm the significant role of glacier retreat on the evolution of glacial lakes. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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随着我国"一带一路"国家新战略提出,"陆上丝绸之路新经济带"建设将面临诸多寒区岩土力学与工程问题,也正成为我国岩土工程领域研究热点.国家自然科学基金作为目前国内自然学科领域最高级别研究支持项目,受到各方广泛关注,所提出的研究课题可谓代表本领域的研究主流与前沿.以"寒区岩土力学与工程"为主题,对本领域近10 a(2006-2015年)获批国家自然科学基金展开资助规模、依托单位及学科门类统计,分析本领域NSFC基金整体发展态势,并对基金研究主题进行分类、整理,对目前本领域发展现状进行了较为系统的分析.基于统计、分析结果,浅析该领域未来应重点关注的研究方向及发展趋势,本综述研究以期为本领域研究人员基金申报及研究主题选择提供参考. 相似文献
996.
Nikolay Emelyanov 《Planetary and Space Science》2010,58(3):411-420
Ephemerides of planetary satellites are needed to address many problems. These ephemerides are used for subsequent observations. A comparison of the available ephemerides with new observations allows the accuracy of the former to be assessed. However, the precision of the ephemerides must be known a priori when solving the tasks. In this paper we formulate and solve the problem of estimating the precision of the ephemerides of outer planetary satellites derived from observations when applied up to the future moments.The methods of assessing the precision of ephemerides involve producing a set of samples of the same ephemeris inferred from observations with different samples of Monte Carlo generated random errors (RO) superimposed onto it. The statistical parameters of simulated observational errors are based on the results of the reduction of real satellite observations. We compute the deviations of the samples of the ephemeris from the standard ephemeris inferred from real observations and adopt the root-mean-square deviation of the apparent coordinates as the precision of the ephemeris. We also use alternative methods: one based on the matrix of covariances of parameter errors (RP), and another one based on bootstrap samples of observations (BS).We use three methods (RO, RP, and BS) to estimate the precision of the ephemerides of all the 107 outer planetary satellites over the 2010-2020 time interval. The precision of the ephemerides of different satellites varies from 0.05 to 4.0 arcsec. For a number of satellites new observations are of vital importance for maintaining the precision of the ephemerides at a level that would allow identification of satellites during the reduction of observations. For some satellites the precision of their ephemerides is of the order of the sizes of their orbits and such satellites can be considered to have been lost. We show that the method of bootstrap samples (BS) can give doubtful results in the cases where there are few observations, which covered a time interval that is shorter than the orbital period of the satellite.Our results suggest obtaining more precise ephemeris making new observations at the times of maximum estimated errors of the ephemeris.All the inferred estimates of the precision of ephemerides are available from the MULTI-SAT ephemeris server: www.imcce.fr/sat (IMCCE), www.sai.msu.ru/neb/nss/index.htm (SAI). 相似文献
997.
George Ferentinos 《Marine Georesources & Geotechnology》2013,31(4):261-277
Abstract The Hellenic Arc is located within one of world's most seismically active areas and has experienced extreme tectonism through Tertiary and Quaternary times. This activity controls the rates of uplift and subsidence and determines the sediments supply and depot centers. This paper discusses the various geological hazards detected in selected parts of the Hellenic Arc and examines the causative factors. The areas surveyed were the North Aegean Trough, the Kythera Ridge in the outer island arc, the Corfu/Kefalinia/Zante shelf/slope, and the Thermaicos, Corinth, Patras, Amvrakia, and Malliacos gulfs, as well as the Trichonis Lake. The potential geological hazards observed are (1) active faulting, (2) sediment instabilities, (3) gas‐charged sediments, (4) salt doming, (5) erosion, transport, and deposition of sediments, and (6) seismicity, volcanism, and tsunamis. The major types of sediment instabilities that have been documented on seabed include (1) surficial sediment creep in slopes ranging from 1 to 2° resulting infolding and faulting of the surficial sediments, (2) translational and rotational slides in slopes ranging from 2 to 40°, (3) debris flow, and (4) turbidity currents. Factors that contribute to slope instability in the Hellenic Arc are (1) sloping bottom, (2) thick accumulations of Plio‐Quatemary sediments, (3) present day high rates of sedimentation, (4) closely spaced active faults, (5) earthquakes, and (6) active diapirism. The contribution of long period waves to slope failure in these areas appears to be of minor importance, since the slope failures occur in depths of more than 150 m. Gas‐charged sediments and pockmarks have been observed in areas associated with deltaic, fjord‐like, and open sea environments. This gas is presumably formed by the decomposition of biogenic material. Numerous disasters that took place during historical times and greatly affected the coastal zone were caused by the above‐mentioned hazards. Damage to offshore installations are limited to cable failure. 相似文献
998.
胡志瑞 《测绘与空间地理信息》2012,35(11):56-59
基于WebGIS、嵌入式移动通讯智能终端应用、影像动态融合等新技术进行了宁夏地质灾害实时预警预报系统的研究,设计了预警预报分析、成果发布、信息反馈、群测群防管理等四大预警预报系统模块。系统采用扩展性强的三层体系结构,基于模块化思想设计,实现了集地质灾害信息管理、分析、发布、反馈于一体的平台。 相似文献
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A new simple, rapid, selective and sensitive analytical procedure based on chemiluminescence (CL) detection is described for the determination of vanadium (V) at sub-nanogram levels in natural waters by use of controlled-reagent- release technology in a flow injection system. The analytical reagents involved in the CL reaction, including luminal and periodate, were both immobilized on anion-exchange resins in a flow injection system. Through water injection, luminol and periodate were eluted from the anion exchange column to generate the chemiluminescence, which was enhanced in the presence of V(V). The increased CL intensity was linear with V(V) concentration in the range from 0.2 to 100 ng mL− 1. The limit of detection was 60 pg mL− 1 (3σ) and the relative standard deviation (RSD) was 1.45% (n = 5) for a 0.5 ng mL− 1 V(V). At a flow rate of 2.0 mL min− 1, including sampling and washing, a typical analytical procedure could be performed in 0.5 min with a RSD of less than 3.0%. The proposed method was successfully applied to determine vanadium in natural waters, and the results were in good agreement with those obtained by ion chromatography. 相似文献