沉降监测多项式回归分析与神经网络预测     

田丰  文鸿雁  张静 《海洋测绘》2007,27(4):23-27

使用多项式和切比雪夫(Tchebyshev)多项式分别对沉降监测数据进行回归分析以预测未来沉降值,其中切比雪夫多项式的外推效果较好;应用前向BP神经网络对两种不同的单因子输入模式进行非线性函数逼近,并进行了不同采样步长的比较,实例表明将时间点作为网络的输入对沉降进行预测效果较好。  相似文献   

Progress in Scatterometer Application   总被引：10，自引：0，他引：10  

W. Timothy Liu 《Journal of Oceanography》2002,58(1):121-136

Progress in the scientific application of space-based scatterometer data over the past two decades is reviewed. There has been continuous improvement in coverage, resolution, and accuracy. Besides the traditional applications in weather and ocean-atmosphere interaction, which are based on ocean surface wind vectors, emerging applications over land and ice are also described. Future missions and new technology are introduced. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

A New Fall-Rate Equation for T-5 Expendable Bathythermograph (XBT) by TSK     

Kizu  Shoichi  Yoritaka  Hiroyuki  Hanawa  Kimio 《Journal of Oceanography》2005,61(1):115-121

The accuracy of the manufacturer’s fall-rate equation for the T-5 Model of expendable bathythermograph (XBT) has been investigated based on about 300 collocated pairs of XBT-CTD (Conductivity-Temperature-Depth profiler) measurements in various climatological regions. We found that the equation systematically overestimates depth by about 5% for the T-5 produced by Tsurumi Seiki, Co. Ltd. (TSK), but almost no bias is associated with the T-5 produced by Sippican, Inc., in USA. The cause of this difference is not clear, because the two manufacturers’ T-5 probes are reported to have identical shape and weight in water. We propose a new fall-rate equation for the TSK T-5: z(t) = 6.54071t - 0.0018691t ², where z(t) is depth in meters at time, t, in seconds.  相似文献   

浙江主要气象灾害概述     

温树伟  张淑云 《海洋学研究》1991,9(1):65-71

气象灾害每年都有,只是轻重程度不同。就全国和全省范围来说,很少有真正风调雨顺的年份。本文根据1951～1988年38年的气象历史资料及有关政府部门的材料、简报、报道,统计出台风、洪涝、海上大风和强对流等几种主要气象灾害对浙江经济造成损失和伤亡人数。文中对主要气象灾害的特点、一般规律和灾情作了概述,并列出一些典型实例,提出了预防气象灾害的意见。  相似文献   

胶州湾东岸滩涂环境的遥感监测   总被引：3，自引：1，他引：3  

王珍岩  张慧霞  郜昂 《海洋科学》2003,27(8):8-10

利用低潮位陆地卫星TM影像对胶州湾东岸碱厂白水分布与扩散进行监测。对研究区的子区影像在ENVI中进行增强、变换处理，提取白水、白泥分布与扩散信息，制作大比例尺影像地图，在GIS软件中计算其面积。结合实地验证和历史数据，分析表明，该污染源10多年来面积扩大了4倍，  相似文献   

Recorder-Dependent Temperature Error of Expendable Bathythermograph     

Shoichi Kizu  Kimio Hanawa 《Journal of Oceanography》2002,58(3):469-476

The accuracy of temperature measurement by the expendable bathythermograph (XBT) is examined for five types of recorders by comparison with co-located CTD measurements and statistical analysis of temperature profiles including an isothermal layer. A positive temperature error increasing downward is occasionally detected for two types of Japanese recorder which have been commonly used among Japanese oceanographic institutions and marine observatories. This error resembles to that reported by Bailey et al. (1989) and Wright (1991) for a different type of recorders, although its cause is not clearly understood. The irregular occurrence of the error suggests that the problem is not solely due to the recorders but rather by some inconsistency of the whole measuring system including them, an XBT probe and sea water. The error is estimated to increase at a rate of O (0.1°C/100 m), and it could be close to 1°C at the deepest part of the profiles (760 m for Tsurumi T-7). This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

九龙江口红树林上附着动物的生态   总被引：12，自引：2，他引：12  

周时强  洪荣发 《台湾海峡》1993,12(4):335-341

福建九龙江口红树林附着动物７种，白脊藤壶Ｂａｌａｎｕｓ ａｌｂｉｃｏｓｔａｔｕｓ和白条地藤壶Ｅｕｒａｐｈｉａ ｗｉｔｈｅｒｓｉ在数量上占绝对优势，是危害红树的主要附着动物。附着动物在河口红树林区的数量分布随着盐度的降低而减少，其栖息密度和生物量的高峰期在夏，秋两季。生长茂密的红树林（郁蔽度大于０．５），附着动物主要分布于水流畅通的向海边缘和潮沟边缘的红树上。水流畅通程度是影响附着动物在红树林区向纵  相似文献   

利用卫星遥感监测南极海冰的研究和进展     

郝春江  解思梅 《海洋预报》1996,13(4):9-14

本文是根据南极“八五”国家攻关课题中的“南极海冰监测和预报”的考核目标，实现为南极考察船在 冰区中航行提供精确和清晰的冰图和预报。  相似文献   

Spatial Variation in the Structure of Kelp Forest Communities Along a Wave Exposure Gradient     

Christopher  Harrold  James  Watanabe Susan  Lisin 《Marine Ecology》1988,9(2):131-156

Abstract. Four sites were sampled in kelp (Macrocysiis pyrifera) forests occupying rocky bottom habitats along a wave exposure gradient in central California. Consistent betwecn-site differences were found in the three major structural elements - the surface canopy, the undcrstory assemblage, and the ground cover/turf assemblage - of kelp forest communities. Macrocysiis pyrifera was found at all four sites. Nereucyslis tuelkeana only at the most exposed site. The understory kelps Laminaria setchellii and Pterygopltora californica were also characteristic of exposed sites. Articulated coralline algae were more abundant at exposed sites than protected, while fleshy red algae showed the opposite pattern. All four study sites were located along 8.5 km of coastline, and thus were assumed to have available to them the same species pool for colonization. The substrate composition was the same and the amount of unconsolidated substrate was similar at all four sites. We suggest that exposure to wave-generated water motion, through its influence on the surface canopy and therefore on the amount of light reaching the bottom, is responsible for these between-site differences.  相似文献   

SeagrassNet monitoring across the Americas: case studies of seagrass decline   总被引：2，自引：0，他引：2  

Frederick T. Short  Evamaria W. Koch  Joel C. Creed  Karine M. Magalhães  Eric Fernandez  & Jeffrey L. Gaeckle 《Marine Ecology》2006,27(4):277-289

Seagrasses are an important coastal habitat worldwide and are indicative of environmental health at the critical land–sea interface. In many parts of the world, seagrasses are not well known, although they provide crucial functions and values to the world's oceans and to human populations dwelling along the coast. Established in 2001, SeagrassNet, a monitoring program for seagrasses worldwide, uses a standardized protocol for detecting change in seagrass habitat to capture both seagrass parameters and environmental variables. SeagrassNet is designed to statistically detect change over a relatively short time frame (1–2 years) through quarterly monitoring of permanent plots. Currently, SeagrassNet operates in 18 countries at 48 sites; at each site, a permanent transect is established and a team of people from the area collects data which is sent to the SeagrassNet database for analysis. We present five case studies based on SeagrassNet data from across the Americas (two sites in the USA, one in Belize, and two in Brazil) which have a common theme of seagrass decline; the study represents a first latitudinal comparison across a hemisphere using a common methodology. In two cases, rapid loss of seagrass was related to eutrophication, in two cases losses related to climate change, and in one case, the loss is attributed to a complex trophic interaction resulting from the presence of a marine protected area. SeagrassNet results provide documentation of seagrass change over time and allow us to make scientifically supported statements about the status of seagrass habitat and the extent of need for management action.  相似文献