中国沿岸主要验潮站海图深度基准面的计算与分析

对中国沿岸有代表性的15个验潮站的多年潮位观测资料，以年序列进行调和分析并据调和常数计算验潮站的海图深度基准面，分析了由年观测序列求得的调和常数和海图深度基准面的稳定性，研究和更新了理论上可能最低潮面计算中的浅水分潮和长周期分潮订正算法。计算结果表明，中国沿岸不同验潮站的海图深度基准面定义和算法存在差异，新的订正算法计算的可能最低潮面和最低天文潮面具有意义一致性，研究成果能够用来精化和重新构建中国沿岸海图深度基准面。     

天津海域深度基准面L值模型构建

基于天津港邻近海域构建的精密潮汐模型,由区域精密潮汐模型各网格点的调和常数,按深度基准面L值的定义算法计算生成网格形式的L值模型。采用天津海域11个验潮站的深度基准面L值对L值模型实施订正,构建了天津海域1'×1'的深度基准面L值模型。     

临时验潮站深度基准面传递模型及其适用性研究

长江口区域瞬时潮汐面受潮汐、径流、风暴潮的耦合作用,具有一定的区域特性。在阐述临时验潮站各种传递模型的基础上,考虑径流季节特性与潮汐特性,利用长期验潮站传递不同时间序列下深度基准面,探讨了各种传递模型在季节特性与潮汐特征组合条件下传递精度及其适用性,提出了长江口区域海图测绘深度基准面传递的优选方案,具有较强的实用性与可操作性。     

海图深度基准面传递算法的精度分析

基于最小二乘潮位拟合传递法的数学模型,对短期验潮站海图深度基准面确定方法进行了研究.用实例对所提方法和<海道测量规范>中求取短期验潮站海图深度基准面方法进行了分析比较;探讨了影响最小二乘潮位拟合传递法精度的因素.结果表明:最小二乘潮位拟合传递法用于确定短期验潮站海图深度基准面,具有较高精度,并且可从同步时间、地理环境及站间距离等方面进一步提高该法所得海图深度基准面的精度.     

海图深度基准面传递算法的精度分析

基于最小二乘潮位拟合传递法的数学模型,对短期验潮站海图深度基准面确定方法进行了研究。用实例对所提方法和《海道测量规范》中求取短期验潮站海图深度基准面方法进行了分析比较;探讨了影响最小二乘潮位拟合传递法精度的因素。结果表明:最小二乘潮位拟合传递法用于确定短期验潮站海图深度基准面,具有较高精度,并且可从同步时间、地理环境及站间距离等方面进一步提高该法所得海图深度基准面的精度。     

越南沿海潮汐类型分布及极值天文潮位

采用最小二乘法,首先对越南从北至南的33个沿海验潮站的长期（最短是5年,最长是53年）观测资料进行潮汐调和分析得到各站的调和常数,再根据分潮O1、K1、M2的振幅值计算指数 V=(HO1+HK1)/HM2,进而结合各站的V值和实际观测资料,指出：越南北部沿岸潮汐性质类型为正规全日潮,潮汐振幅在2.5?4.5m范围内;越南中部沿岸潮汐性质较复杂,该海岸具有三种潮汐类型,包括不正规日潮,不正规半日潮和正规全日潮,潮汐振幅较小,大致在0.5?2.5m范围内;越南南部沿岸潮汐性质为不正规半日潮,潮汐振幅在3.0?4.0m左右;越南西南部沿岸潮汐性质类型为不正规日潮,潮汐振幅大致在1.0?2.0m范围内。从上述33个潮站中选取了12个验潮站,计算了各站包括114分潮的潮汐调和常数,采用潮汐预报法推估出各站20年间（1987?2007）的天文潮位序列,从天文潮位序列中取出最高和最低值。因为这些验潮站的观测时间跨度较长、潮高数据序列较稳定、潮汐调和分析精度较高,均方根都小于?10cm,并有较高可靠性。最后,对本文研究结果提出了几点认识和建议     

基于Jason-1卫星测高数据提取海洋潮汐信息研究

为深入研究中国近海区域海洋潮汐活动,基于Jason-1约6年的卫星测高GDR数据,采用调和分析法提取了中国近海区域交叉点的潮汐信息,得到主要分潮的振幅分布图。将其与验潮站资料和FES2004全球海潮模型相比较,其分潮振幅差异基本在3cm以内,结果符合性较好。     

利用经优化的边界条件开展黄海海州湾潮汐场模拟

受海底地形、开边界驱动水位及底摩擦系数等边界条件的共同影响,当前中国沿岸和近海潮汐场模拟的精度仍显不足。利用精度和分辨率较海图高一级别的水深数据、包含长周期天文气象分潮Sa的由12个主分潮组成的开边界驱动水位及顾及水深空间变化的底摩擦系数等经优化的边界条件,运行二维潮汐数值模式2D-MIKE21,开展黄海海州湾潮汐场模拟。结果表明,天文潮模拟值与海州湾周边6个验潮站1年潮汐表相比,12个主分潮综合预报误差为5.52 cm;与中国海域现有潮汐模型CST1中24个随机点位相比,12个主分潮综合预报误差为7.10 cm。天文潮模拟值和CST1预报值二者与海州湾周边2个验潮站近1个月实测值相比,前者中误差要小于后者。这为在沿岸及近海开展面向海洋测绘应用的潮汐场模拟提供了新思路,同时也表明通过数值模拟的方式构建天文气象分潮Sa是可行的。     

广东省统一深度基准项目的设计研究

根据对广东省现有长期验潮站数量、分布以及水位数据情况的分析,确立了在已有长期验潮站的基础上,采用适当布设短期验潮站的方式,对长期验潮站进行加密补充;建立海区调和常数变化模型,并结合水深数据、卫星测高数据,构建海洋潮汐模型;最终建立深度基准模型的总体设计思路。广东省统一深度基准的建立,可实现深度基准面1985高程模型的构建,相邻测区间水深成果的无缝拼接,沿海水深成果与陆地地形成果的相互转换,GNSS技术下的水深测量(无验潮模式)以及对沿海范围内海岸线和海岛岸线的精确推算。     

利用验潮站资料的中国近岸海潮模型精度评估

针对全球海潮模型在我国近海海域精度较差的问题,该文采用中国沿岸30个长期验潮站的调和常数,对比了3种全球海潮模型DTU10、TPXO7.2、NAO.99b和1个区域海潮模型NAO.99Jb在中国沿岸的准确度。通过海潮模型与验潮站分潮的振幅中误差、迟角中误差以及8个主要分潮的预报误差,对渤海、黄海、东海和南海北部进行了详细的分析。结果表明,NAO.99Jb在中国海域精度最高,NAO.99b次之。在渤海海域,DTU10在Q_1分潮精度最高,NAO.99b在K2分潮精度最高,其余分潮均是NAO.99Jb精度最高;在黄海海域,NAO.99b在Q_1分潮精度最高,其余分潮均是NAO.99Jb精度最高;在东海海域,DTU10在Q_1分潮精度最高,TPXO7.2在P1精度最高,NAO.99Jb在O1、M2分潮精度最高,其余分潮均是NAO.99b精度最高;在南海北部海域,DTU10在N2、S2分潮精度最高,其余分潮均是NAO.99Jb精度最高。     

阿克苏河-塔里木河水系水质污染遥感监测与评价

 采用Landsat TM数据分析了阿克苏河—塔里木河断面水质污染状况,通过波段的DN值和常规监测数据建立能反映水质状况的 污染物监测模型。结果发现,将2000年常规监测数据代入模型后,与遥感数据的结果基本吻合| 重建阿克苏河—塔里木河的连续水体 污染变化曲线,得出污染物浓度随着远离上游而增加。     

Monitoring drought dynamics in the Aravalli region (India) using different indices based on ground and remote sensing data

The hard-rock hilly Aravalli terrain of Rajasthan province of India suffers with frequent drought due to poor and delayed monsoon, abnormally high summer-temperature and insufficient water resources. In the present study, detailed analysis of meteorological and hydrological data of the Aravalli region has been carried out for the years 1984–2003. Standardised Precipitation Index (SPI) has been used to quantify the precipitation deficit. Standardised Water-Level Index (SWI) has been developed to assess ground-water recharge-deficit. Vegetative drought indices like Vegetation Condition Index (VCI) and Temperature Condition Index (TCI) and Vegetation Health Index (VHI) have been computed using NDVI values obtained from Global Vegetation Index (GVI) and thermal channel data of NOAA AVHRR satellite. Detailed analyses of spatial and temporal drought dynamics during monsoon and non-monsoon seasons have been carried out through drought index maps generated in Geographic Information Systems (GIS) environment. Analysis and interpretation of these maps reveal that negative SPI anomalies not always correspond to drought. In the Aravalli region, aquifer-stress shifts its position time to time, and in certain pockets it is more frequent. In comparison to hydrological stress, vegetative stress in the Aravalli region is found to be slower to begin but quicker to withdraw.     

Landslide risk analysis between Giri and Tons Rivers in Himachal Himalaya (India)

The area around Sataun in the Sirmur district of Himachal Pradesh, India (falling between the rivers Giri and Tons; both tributaries of the Yamuna River) was studied for landslide vulnerability on behalf of the inhabitants. The study was made using extensive remote sensing data (satellite and airborne). It is well supported by field evidence, demographic and infrastructural details and aided by Geographic Information System (GIS) based techniques. Field observations testify that slope, aspect, geology, tectonic planes, drainage, and land use all influence landslides in the region. These parameters were taken into consideration using the statistical approach of landslide hazard zonation. Using the census data of 1991, vulnerability of the populace to the landslide hazard was accessed. As most of the infrastructure in the region is concentrated around population centres, population data alone was used for vulnerability studies.     

Gravity Changes Before Large Earthquakes in China: 1998-2005

Although it is well known that coseismic gravity changes take place during an earthquake, previous research has not yielded convincing evidence demonstrating that significant gravity changes occur before large earthquakes. Furthermore, even if we suspect that gravity changes occur before large earthquakes, we have yet to demonstrate how to consistently observe these changes for useful earthquake forecast that would bring benefits to society. We analyzed ground gravity survey data obtained in 1998, 2000, 200...     

GNSS系统及其技术的发展研究

阐述了国际上卫星导航系统的总体发展,对美、俄、欧、中的四大全球系统,以及相关的区域系统和增强系统进行了简单的介绍,研究分析了GNSS系统及其技术的发展趋势,同时分析了我国Compass全球系统面临的机遇和挑战,并提出了我国未来工作的建议.     

“4D”技术及其应用

介绍“４Ｄ”（即数字地面模型、数字正射影像、数字栅格地图和数字线划地图）系列产品的生产流程、关键技术、及其在耕地保护、防灾减灾救灾和城市规划等方面的应用方法。     

Virtual Australia: its key elements – know,think, communicate

Abstract

Virtual Australia is not a well-defined or agreed concept. This discussion paper conceptualises Virtual Australia as a ‘virtual [digital] model containing and representing all non-trivial objects and their contextual environment – from blue sky to bedrock – in real world Australia’. It describes a scenario for Virtual Australia, one or two decades from now, in which the locations and conditions of non-trivial objects and their environment are updated automatically through a combination of remote sensing and wireless communication technologies in support of a ‘Supranet’. It then examines the concept of the ‘Supranet’ – a pervasive information network based largely on wireless technology linking the physical world to a virtual model in real time – and develops and discusses three principal characteristics of the Supranet: the ability to have or collect specific information (know); the ability to process information (think); and the ability to communicate that information. If, in the near future, any or all non-trivial devices are to some extent able to know, think and communicate, the potential for object autonomy will be realised.     

Toward seamless indoor-outdoor applications: Developing stakeholder-oriented location-based services

Location-Based Services (LBS),an emerging new business based on smartphone and mobile networks,are becoming more and more popular.Most of these LBSs,however,only offer non-seamless indoor/outdoor applications and simple applications without giving stakeholders the chance to play an active role.Our specific aim is to solve these issues.This paper presents concepts to solve these issues by expanding the Open Location Services Interface Standard (OpenLS) to allow seamless indoor/outdoor positioning and to extend the content of the services to include information recommended by stakeholders.     

GIS空间数据的采集误差及其分析

本文详细阐述了GIS数据采集过程中的误差来源，重点分析了通过地图、遥感和摄影测量等方式采集数据所产生的误差及其特性，分析了其对GIS数据的影响与消减方法。     

地理数据库的关系模型及其实现

本文从以图论观点分析地理实体入手,系统阐述了地理数据库关系模型的设计法和过程。作者于1984年4～9月间在微型机上设计建立了关系型地理数据库的实方验系统(RGDB)。该系统采用了本文提出的关系模型,采用了可动态扩库的子库组合结构,这种结构具有灵活性和提高空间利用率的优点。RGDB含有多种功能的数据操作命令,除了具有一般检索功能外,还能进行“开窗”选取和十分“自由”的映象选取。本文对RGDB系统的主要性能和实现途径作了扼要介绍。