Analysis of multi-dimensional SAR for determining the thickness of thin sea ice in the Bohai Sea   总被引：1，自引：0，他引：1  

张晰  张杰  孟俊敏  苏腾飞 《中国海洋湖沼学报》2013,31(3):681-698

Flat thin ice (<30 cm thick) is a common ice type in the Bohai Sea, China. Ice thickness detection is important to offshore exploration and marine transport in winter. Synthetic aperture radar (SAR) can be used to acquire sea ice data in all weather conditions, and it is a useful tool for monitoring sea ice conditions. In this paper, we combine a multi-layered sea ice electromagnetic (EM) scattering model with a sea ice thermodynamic model to assess the determination of the thickness of flat thin ice in the Bohai Sea using SAR at different frequencies, polarization, and incidence angles. Our modeling studies suggest that co-polarization backscattering coefficients and the co-polarized ratio can be used to retrieve the thickness of flat thin ice from C- and X-band SAR, while the co-polarized correlation coefficient can be used to retrieve flat thin ice thickness from L-, C-, and X-band SAR. Importantly, small or moderate incidence angles should be chosen to avoid the effect of speckle noise.  相似文献   

渤海生态系统健康评价及对策研究     

宋德彬  高志强  徐福祥  郑翔宇  张华  胡晓珂  黄国培  章海波 《海洋科学》2017,41(5):17-26

根据2014~2016年渤海各航次监测数据,选择22项因子构建表征研究区水环境、沉积环境、生态系统健康状态的评价指标体系,利用AHP层次分析方法对渤海生态系统的健康状况进行了评价。结果表明,渤海综合生态指数CEI为0.643,健康等级为中级,表明渤海生态系统整体处于亚健康的状态。生态健康较差和差的区域主要集中在莱州湾-渤海湾及其毗连地带的黄河三角洲地区;唐山-秦皇岛-葫芦岛近海及其纵深海域大体处于中级健康水准;渤海中部海区及其毗连的渤海海峡区域,海洋生态健康水平较高。根据评价结果,认为陆源输入、围填海工程是莱州湾和渤海湾的主要胁迫因子,并探讨了相应对策,以期为渤海的综合管理提供决策支持。  相似文献   

黄渤海北部沿海大风时空变化特征   总被引：5，自引：0，他引：5       下载免费PDF全文

吴曼丽  陈宇  王瀛  乔小湜  梁寒  陆井龙  李爽 《气象与环境学报》2012,28(6):65-71

基于1971-2008年黄渤海北部沿海18个基本气象站风向、风速历史资料和NCEP再分析资料,利用统计学、小波分析和天气学分型方法分析了黄渤海北部辽宁沿海风场时空变化特征。结果表明：黄渤海北部沿海大风呈明显减少趋势,大风主要出现在春季,4月最多,11月份次之。风向主要以偏北风和偏南风为主,夏半年主要以南风为主,冬半年盛行偏北风。海上大风的天气学分型主要划分为冷锋后部型、高压后部型、台风型和气旋型,其中气旋型又包括江淮气旋型、华北气旋型、蒙古气旋型和东北低压型;冷锋后部型大风出现次数最多,气旋型次之,台风型最少。  相似文献   

Perfluoroalkyl and polyfluoroalkyl substances in sediments from South Bohai coastal watersheds,China     

Zhaoyun Zhu  Tieyu Wang  Pei Wang  Yonglong Lu  John P. Giesy 《Marine pollution bulletin》2014

This study investigated the concentrations and distribution of Perfluoroalkyl and polyfluoroalkyl substances (PFAS) in sediments of 12 rivers from South Bohai coastal watersheds. The highest concentrations of ΣPFAS (31.920 ng g⁻¹ dw) and PFOA (29.021 ng g⁻¹ dw) were found in sediments from the Xiaoqing River, which was indicative of local point sources in this region. As for other rivers, concentrations of ΣPFAS ranged from 0.218 to 1.583 ng g⁻¹ dw were found in the coastal sediments and from 0.167 to 1.953 ng g⁻¹ dw in the riverine sediments. Predominant PFAS from coastal and riverine areas were PFOA and PFBS, with percentages of 30% and 35%, respectively. Partitioning analysis showed the concentrations of PFNA, PFDA and PFHxS were significantly correlated with organic carbon. The results of a preliminary environmental hazard assessment showed that PFOS posed the highest hazard in the Mi River, while PFOA posed a relative higher hazard in the Xiaoqing River.  相似文献   

数字海底的理论基础和技术实现--以渤海油田工程地质示范区系统为例   总被引：1，自引：0，他引：1  

郑彦鹏  梁瑞才  王勇  孟恩  韩国忠  苏天赟  张政民 《海洋科学进展》2004,22(3):352-358

渤海油田资源的勘探开发促进了海洋工程建设的迅速发展。为避免海底不稳定性造成海洋工程巨大损夫或灾难性后果,在该区开展了大规模的海洋工程地质综合调查和评价研究。通过对数字海底技术的理论基础研究和在渤海油田工程地质示范区的具体实践,基于GIS理论、计算机硬件、软件以及网络技术,对渤海油田工程建设中的多源异构数据和图形进行标准化/整合、输入/输出、存储、查询和显示,研究开发的示范区系统可提供多种综合分析及应用服务,为海洋工程建设和油田工程安全保障提供了共享基础科学数据,对于防止海洋地质灾害、降低工程建设造价和保障工程安全运行具有重大的应用价值。  相似文献   

基于模糊综合评价模型的天津滨海新区湿地生态系统健康评价   总被引：3，自引：0，他引：3  

王秀明  李洪远  孟伟庆 《湿地科学与管理》2010,6(3):19-23

以环渤海地区的天津滨海新区湿地为例,运用模糊综合评价模型对湿地生态系统的健康进行了诊断评价。首先从湿地生态特征、整体功能特征和社会经济3方面选取26个评价指标,构建了天津滨海新区湿地生态系统健康的评价体系。评价等级分为很健康、健康、一般、一般病态、疾病5级,运用定量与定性相结合的方法界定等级。运用模糊综合评价模型对天津滨海新区湿地生态系统健康进行诊断,评价综合得分为0.48,健康水平处于疾病状态,主要表现在水质污染严重和水源保证水平低、景观破碎化、功能退化3个方面。  相似文献   

Taxonomic distinctness of macrofauna as an ecological indicator in Laizhou Bay and adjacent waters     

Hong Zhou  Er Hua  Zhinan Zhang 《中国海洋大学学报(英文版)》2010,9(4):350-358

In this paper, we assessed the ecological and biodiversity status in the Bohai Sea through a quantitative survey on mac-rofaunal community at 25 stations in Laizhou Bay and adjacent waters in the autumn of 2006.We tested the robustness and effectiveness of taxonomic distinctness as an ecological indictor by analyzing its correlation with species richness and natural environmental variables and by analyzing other ecological indicators (Shannon-Wiener H' and W statistics from Abundance Biomass Comparison curve).Results so obtained indicated that the benthic environment of the study waters in general is not under major impact of anthropogenic disturbance, but some stations in Laizhou Bay and along the coast of the Shandong Peninsula and even in the central Bohai Sea might be moderately disturbed and showed signs of ecological degradation.The taxonomic distinctness measures △+ and Λ+ were independent of sampling effort and natural environment factors and were compliant to other ecological indicators.Further application of the taxonomic distinctness indicator to assess marine biodiversity and ecosystem health on a larger regional scale with historical data seems promising.  相似文献   

渤海湾盆地沉积斜坡及其含油气性   总被引：6，自引：6，他引：0  

王海潮  王余泉  秦云龙  杨彩虹  李莉  吕庆玲  傅建利 《地质力学学报》2006,12(1):23-30

将渤海湾盆地的沉积斜坡按结构分为3类4种,并归纳出4种相应的沉积序列;按沉积相将砂体划分为8种储集层类型,以河流——三角洲砂为最佳储层;并归纳出斜坡带的4种油气藏分布模式;总结了斜坡带油气聚集的基本条件;通过对4种斜坡的类比表明:凹坡型为最佳含油斜坡。并对冀中坳陷斜坡带的油气勘探提出了建议。   相似文献   

渤海湾盆地济阳坳陷潜山油藏分布规律及控制因素   总被引：8，自引：7，他引：1  

首皓  黄石岩 《地质力学学报》2006,12(1):31-36

济阳坳陷潜山油藏类型复杂,构造裂缝是油藏的主要储集空间。济阳坳陷潜山储层的分布主要受控于盆地的形成过程,构造运动是控制潜山分布的最主要的因素。潜山储层非均质性强,且不同潜山的储层性质存在较大差异。济阳坳陷潜山油藏的开发特征复杂,稳产阶段短、产能差异大、含水上升快。中生代及以前形成的古地貌早隆潜山是济阳坳陷最有利的潜山油藏勘探目标。   相似文献   

A three-dimensional model study on ocean dynamic response to traveling cyclone over the Huanghai Sea     

QIN Zenghao  LI Yongping  YUAN Yaochu  YU Runling 《海洋学报(英文版)》2005,24(1):60-75

On the basis of numerical simulation of the mean circulation and relevant thermal-salinity fields in June with a three-dimensional ocean model (ECOM-si), the model outputs are used as first guess of initial fields for numerical integration of the model equations and the numerical results are applied to investigating the dynamical responses of the Huanghai Sea and the East China Sea (HECS) in the course of a weak land-to-sea cyclone‘s passage over the Huanghai Sea on 15-16 June 1999. Predominance of the dynamic impact of cyclone over the thermal one in June in the HECS is justified using observations and model simulations.The cyclone and its surrounding weather system, i.e,, subtropical high ridge to its south could influence current and thermal fields in the Bohai Sea, the Huanghai Sea and the northern East China Sea even though the intensity of cyclone was rather weak. The response of oceanic currents to the wind stresses driven by the cyclone and its southern subtropical high were strongly characterized by the wind drift with its extent of equivalent scale of cyclone in the horizontal and of Ekman layer in the vertical. The sea response at a given site was closely related to the transient local wind speed and direction,especially was sensitive to the local wind direction,which is demonstrated at three points locating at the southern and western Huanghai Sea and the northern East China Sea. So the sea responses at locations differed considerably from one another. Current responded to the wind stress in a simple way:directly to the wind-driven current and subsequent gradient current and slope current, etc., whereas sea temperature responded to the wind stress in two ways: directly to the cyclone-induced cooling and indirectly to water movements both in the horizontal and the vertical by the cyclone‘ s wind stress. So the sea temperature variation under the influence of cyclone was more complicate than the current. The HECS in response to the cyclone and its ambient weather system was likely to be a fast process and such a response could last at least for more than 1d. Current increased with the duration of wind stress exerted on the surface and decreased with the increasing depth. Affected by the cyclone, the maximum sea surface temperature decreased by almost 1.6℃ during the 24h cyclone.  相似文献