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本文介绍了一种旨在观测沿岸表层流的自制"表层海流实验"漂流浮标,该浮标基于GPS信号、简易且十分经济(每个约$30)。通过分析在大亚湾布放的六个漂流浮标轨迹和由此推算得到的流速发现,此类浮标基本可以刻画广东沿岸冬季表层流的特征。 相似文献
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用表层漂流浮标对海上溢油实时跟踪和监测的方法 总被引:1,自引:0,他引:1
一种适用于近海使用的表层漂流浮标,利用GPS定位,通过GSM/CDMA网络传输数据,是一种准确实时、成本低廉的环境监测和海流、污染跟踪工具。文章介绍几种溢油跟踪监测方法和特点、表层漂流浮标的设计及其在溢油漂移轨迹跟踪中应用的特点。 相似文献
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随着GPS技术的发展,具有RTK功能的GPS接收机不但在平面位置上可以达到厘束级,而且以WGS84为参考椭球的垂直高程也可以达到厘束级,因而被广泛地应用于海岸带测量中。本文介绍了RTKGPS在海域勘界、无验潮模式水深测量方面的一些具体应用。 相似文献
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Heung-Jae Lie Cheol-Ho Cho Jae-Hak Lee Suk Lee Yuxiang Tang 《Journal of Oceanography》2000,56(2):197-211
The Cheju Warm Current has been defined as a mean current that rounds Cheju-do clockwise, transporting warm and saline water to the western coastal area of Cheju-do and into the Cheju Strait in the northern East China Sea (Lie et al., 1998). Seasonal variation of the Cheju Warm Current and its relevant hydrographic structures were examined by analyzing CTD data and trajectories of satellite-tracked drifters. Analysis of a combined data set of CTD and drifters confirms the year-round existence of the Cheju Warm Current west of Cheju-do and in the Cheju Strait, with current speeds of 5 to 40 cm/s. Saline waters transported by the Cheju Warm Current are classified Cheju Warm Current water for water of salinity greater than 34.0 psu and modified Cheju Warm Current for water having salinity of 33.5–34.0 psu. In winter, Cheju Warm Current water appears in a relatively large area west of Cheju-do, bounded by a strong thermohaline front formed in a "" shape. In summer and autumn, the Cheju Warm Current water appears only in the lower layer, retreating to the western coastal area of Cheju-do in summer and to the eastern coastal area sometimes in autumn. The Cheju Warm Current is found to flow in the western channel of the Korea/Tsushima Strait after passing through the Cheju Strait, contributing significantly to the Tsushima Warm Current. 相似文献
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Eric D. Barton Javier Arístegui Paul Tett Eleuteria Navarro-Prez 《Progress in Oceanography》2004,62(2-4):71
The physical background to a suite of biological studies carried out in the Canary Islands upwelling region is presented. The area is unique in that the coastal transition zone is spanned by an archipelago of islands that shed mesoscale eddies of diameter 50–100 km into the alongshore flow. A recurrent filament and eddy system was sampled intensively to study the changing properties of waters as they are advected towards the open ocean in the filament and to investigate the exchanges between filament and eddies. The system was more complex than previously revealed. In early August, a single filament extended offshore from near Cape Juby. Two weeks later, a second filament had developed slightly farther north and extended offshore to merge with the first at 100 km offshore. The merged filament was entrained around a recurrent, topographically trapped cyclonic eddy and interacted with transient cyclonic and anticyclonic eddies shed from the island of Gran Canaria. Between the two filaments and the coast, a pair of counter-rotating eddies re-circulated water parcels for several weeks. Surface layer drifters cycled around this near-shore re-circulation several times before following convoluted paths that demonstrate significant exchange between continental shelf and open ocean waters. 相似文献
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Plastic pollution has biological, chemical, and physical effects on marine environments and economic effects on coastal communities. These effects are acute on southeastern Hawai‘i Island, where volunteers remove 16 metric tons of debris annually from a 15 km coastline. Although the majority is foreign-origin, a portion is locally-generated. We used floating debris-retention booms in two urban waterways to measure the input of debris from Hilo, the island’s largest community, and released wooden drifters in nearby coastal waters to track the fate of that debris. In 205 days, 30 kilograms of debris (73.6% plastic) were retained from two watersheds comprising 10.2% of Hilo’s developed land area. Of 851 wooden drifters released offshore of Hilo in four events, 23.3% were recovered locally, 1.4% at distant locations, and 6.5% on other islands. Comparisons with modeled surface currents and wind were mixed, indicating the importance of nearshore and tidal dynamics not included in the model. This study demonstrated that local pollutants can be retained nearby, contribute to the island’s debris-accumulation area, and quickly contaminate other islands. 相似文献
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Space technologies, such as kinematic Global Positioning System (GPS), often combined with an inertial navigation system (INS), provide an efficient direct georeferencing tool for remote sensing and aerial surveying. Practically, these systems are now able to deliver high-precision orientation data for spatial data acquisition platforms in a timely manner, at relatively low cost, as compared to traditional methods. The Airborne Integrated Mapping System (AIMS (TM)), developed at The Ohio State University Center for Mapping, integrates high-resolution digital imagery, differential GPS/INS, and precise timing for high-quality data acquisition supporting large-scale mapping and other precise positioning applications. In this article, the AIMS (TM) system hardware/software configuration, its current operational capabilities, and the test results of airborne mapping of the coastal zone are presented. 相似文献
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Space technologies, such as kinematic Global Positioning System (GPS), often combined with an inertial navigation system (INS), provide an efficient direct georeferencing tool for remote sensing and aerial surveying. Practically, these systems are now able to deliver high-precision orientation data for spatial data acquisition platforms in a timely manner, at relatively low cost, as compared to traditional methods. The Airborne Integrated Mapping System (AIMS (TM)), developed at The Ohio State University Center for Mapping, integrates high-resolution digital imagery, differential GPS/INS, and precise timing for high-quality data acquisition supporting large-scale mapping and other precise positioning applications. In this article, the AIMS (TM) system hardware/software configuration, its current operational capabilities, and the test results of airborne mapping of the coastal zone are presented. 相似文献
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E. G. Lunev V. A. Ivanov A. G. Kirichenko E. M. Lemeshko S. V. Motyzhev 《Physical Oceanography》2011,20(5):366-378
The autonomous drifting buoys equipped with satellite link turn into one of the most important components of the global system
of operative observations of the ocean and the surface layer of the atmosphere. However, on the regional level, the problem
of analysis of the surface circulation of waters in the coastal zone and sea straits remains quite urgent because the available
drifters cannot be used in this case due to their sizes and long intervals between measurements. We present the results of
development and testing of a new drifter system aimed at measuring currents. The system is based on the use of buoys operating
at depths less than 1 m. To improve the space-and-time resolution of measurements, the buoys are equipped with receivers of
the global positioning system (GPS) and GSM modems for the data transfer via cellular communication networks. The drifter system guarantees the possibility of determination
of the coordinates of buoys with a resolution of 3 min in time and 14 m in space. We describe the specific features of the
design of the proposed information-and-measuring drifter system and present the first results of application of new buoys
called “minidrifters” for the pilot monitoring of currents in the Kerch Strait. 相似文献
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平缓潮滩的测绘受到潮汐和淤泥的双重影响,难以进行大区域的人工作业。探讨利用序列遥感影像构建潮滩DEM的技术方法。基于多时相BJ-1小卫星自动提取水边线,利用中国近海高分辨率潮位网格,与卫星过境时刻的水边线进行空间关联与内插,生成带有高程值的系列水边点,并以此来构建潮滩地形三角网,最后生成格网潮滩DEM。与现场RTK验证的三个剖面的高程相比,其高程绝对误差均值小于0.2m。结果表明,应用中分辨率遥感影像进行淤泥质潮滩地形反演可以达到一定比例尺的制图精度。 相似文献
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海岸带是重要海陆过渡带地貌单元与区域,兼受海陆动力双重作用与影响,包括不同类型的沉积相,经历复杂的动力沉积、地貌演变及灾变过程。海岸带调查涉及学科交叉融合,调查要素相对独立与内容多学科交叉并存。我国曾分别于1960年、1981年和2003年组织开展过全国海岸带综合调查工作,调查获取了大量丰硕成果。当前海岸带调查与研究过程中亦暴露出一些亟需突破问题,包括:1)海岸带存在大范围"盲区",浅水易陷、礁石养殖等区域难以到达,成为海岸带数据"空白区"、调查"禁区";2)我国海岸带观测平台数量少、分布零散,未形成综合有效观测网,导致长时间序列、多源准同步调查数据缺乏,难以准确把握海岸带变化规律,破解资源环境有关问题;3)海岸带数据获取智能化程度低,严重阻碍制约有关对策及时有效性;4)海岸带不同学科协同调查、交叉融合研究模式尚未建立,不能及时发现海岸带科学问题。今后海岸带调查将在海岸带高分辨率过程数据、全覆盖无死角实时动态数据获取技术,长时间序列综合数据采集平台建设,陆海空全天候立体化数据采集传输及快速智能决策,以及海岸带多学科交叉攻关研究等方面取得突破。 相似文献
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Richard Limeburner Robert C. Beardsley 《Deep Sea Research Part II: Topical Studies in Oceanography》1996,43(7-8)
Satellite-tracked drifters with drogues centered near-surface (5 m) and below the seasonal thermocline (50 m) were launched during late winter and spring of 1988 and 1989 in the northern Great South Channel in the western Gulf of Maine to investigate the regional circulation as part of the South Channel Ocean Productivity Experiment (SCOPEX). Many of the near-surface drifters became entrained in the clockwise gyre over Georges Bank, and eight drifters made a total of 16 complete circuits around the bank during the stratified season. The average recirculation period of these eight drifters was 48 days, and the average drifter speed around the bank was 12 cm s−1. There is no clear evidence from the drifter data that the strength of the clockwise gyre over the bank increased with time during the stratified season. On average, these drifters (i) followed a relatively narrow path around the bank, except over the eastern end of the bank where three preferred paths were observed, (ii) moved fastest over the northern and southern flanks of the bank, (iii) did not enter a core area of 3500 km2 centered at 41°17′N, 68°00′W, approximately 30 km southwest of the topographic center of the bank, and (iv) stopped circling the bank by the end of November, due in part to strong wind events that appeared to drive drifters off the bank. Curiously, none of the near-surface drifters moved from the southern flank of Georges Bank onto the New England shelf as might be expected from continuity of flow along the outer shelf; instead, the drifters that circled the bank tended to move off the bank along its southern flank. None of the drifters with drogues centered at 50 m appeared to recirculate around Georges Bank. 相似文献
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海岸带生态地质环境脆弱性评价指标体系研究 总被引:1,自引:0,他引:1
海岸带环境是一种不可再生资源,为了对其进行保护性开发,对海岸带生态地质环境的脆弱性进行综合评价,并在此基础上做出合理的开发决策是非常重要的。通过对可能危害海岸带环境的压力因素进行了综合分析,提出可以描述和表征环境变化的相关参数,建立了一套具有一定普适意义的可用于海岸带生态地质环境评价的指标体系。 相似文献
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Shinya Magome Tomohiro Yamashita Takeshi Kohama Atsushi Kaneda Yuichi Hayami Satoru Takahashi Hidetaka Takeoka 《Journal of Oceanography》2007,63(5):761-773
Jellyfish patch formation is investigated by conducting a drifter experiment combined with aerial photography of a sustained
patch of the moon jellyfish in Hokezu Bay, Japan. Jellyfish patches are aggregations of individuals that are caused by a combination
of swimming (active influence) and advection by currents (passive influence). The drifter experiment involved the injection
of 49 drifters around a distinct surface patch of jellyfish within an area of approximately 300 m × 300 m. The drifters’ motion,
caused only by the passive influence, was recorded in a series of 38 aerial photographs taken over approximately 1 h. The
ambient uniform current field larger than the patch scale was estimated from the movement of the centroid position of drifters,
while the distribution of horizontal divergence and relative vorticity around the patch was estimated from the time-derivative
in areas of triangles formed by the drifters. The centroid positions of both drifters and patches moved stably toward the
bay head at different speeds. The difference vector between the patch and drifter centroids was directed to the sun, and was
opposite to the ambient current. The distributions of vorticity and divergence around patches exhibited inhomogeneity within
the patch scale, and the drifters in this nonuniform current field aggregated near the convergence area within 1 h. The results
suggest that horizontal patch formation is predominantly influenced by passive factors at the surface of Hokezu Bay. Furthermore,
the upward swimming against downwelling may make sustained patch in surface layer. 相似文献
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Institutional capacity-building for targeting sea-level rise in the climate adaptation of Swedish coastal zone management. Lessons from Coastby 总被引:1,自引:0,他引:1
For coastal areas across the world, sea-level rise and problems of coastal erosion and coastal flooding are expected to increase over the next hundred years. At the same time political pressure for continued waterfront planning and development of coastal areas threatens to increase our societal vulnerability, and necessitating climate adaptation in coastal zone management. The institutional dimension has been identified as important for ensuring a more robust adaptation to both current climate variability and future climate change. In this paper, lessons regarding institutional constraints for climate adaptation are drawn from a Swedish case-study on local coastal zone management, illustrating the diverse and complex nature of institutional capacity-building. The aim of the paper is to illustrate critical factors that from an institutional perspective condition the capacity to achieve a more integrated, strategic and proactive climate adaptation and for turning “rules on paper” to working practice, based on case-study experiences from Coastby. Following and expanding a framework for analysing institutional capacity-building we learnt that a selective few key actors had played a critical role in building a strong external networking capacity with a flip-side in terms of a weak internal coordinating capacity and lack of mutual ownership of coastal erosion between sectoral units e.g. risk-management, planning and environment. We also found a weak vertical administrative interplay and lack of formal coherent policy, procedures and regulations for managing coastal erosion between local, regional and national administrations. Further, tensions and trade-offs between policy-agendas, values and political priorities posed a barrier for capacity-building in coastal zone management which calls for processes to mediate conflicting priorities in policy-making, planning and decision-making. The case-study suggests that the ability of the political administrative system to acknowledge and deal with institutional conflicts is a critical condition for ensuring an integrated and proactive climate adaptation in coastal zone management. 相似文献