全站仪无棱镜模式在岛礁地形测量中的应用

针对岛礁地形测量的特点,提出了用全站仪无棱镜模式进行碎部点数据采集的方法,从理论上对其精度进行了论证分析,通过公式推导、数据图表分析,得出了全站仪无棱镜模式测定待定点位平面位置精度和点位高程精度与所测距离和天顶距之间的关系。同时通过全站仪的无棱镜模式和有棱镜模式对所选碎部点进行检核,实验数据结果表明都能完全符合规范的要求。     

Thermodynamic effects on particle movement: Wind tunnel simulation results

Sand/dust storms are some of the main hazards in arid and semi-arid zones. These storms also influence global environmental changes. By field observations, empirical statistics, and numerical simulations, pioneer researchers on these natural events have concluded the existence of a positive relationship between thermodynamic effects and sand/dust storms. Thermodynamic effects induce an unsteady stratified atmosphere to influence the process of these storms. However, studies on the relationship of thermodynamic effects with particles (i.e., sand and dust) are limited. In this article, wind tunnel with heating was used to simulate the quantitative relationship between thermodynamic effects and particle movement on different surfaces. Compared with the cold state, the threshold wind velocity of particles is found to be significantly decrease under the hot state. The largest decrease percentage exceedes 9% on fine and coarse sand surfaces. The wind velocity also has a three-power function in the sand transport rate under the hot state with increased sand transport. Thermodynamic effects are stronger on loose surfaces and fine particles, but weaker on compacted surfaces and coarse particles.     

垦利县国土资源管理委员会集体会审系统建设初探

国土资源已成为社会经济发展的基础和根本支撑,如何科学合理的管理、利用资源,关系到整个社会的发展和未来。通过建立垦利县国土资源管理委员会集体会审系统,对土地出让的前期工作做了数字化、信息化,提出一个基于工作流技术和GIS技术的综合解决方案,利用现有的地理信息服务平台,建立会审系统为国土资源管理委员会的集体会审工作提供技术支撑并对出让地块加以管理。     

广东清远市漂流旅游优势与竞争态势分析

广东清远市作为中国第一个也是目前唯一一个“中国漂流之乡”,近几年来,漂流旅游发展得如火如荼,已经成为广东漂流旅游发展得最成功、最成熟的地方以及全国最著名漂流地之一。笔者认为清远市发展漂流旅游的优势在于其气候和资源、区位交通、客源市场及规模集聚效应等方面,其目前面临着来自省内同类产品和非同类产品以及周边省区同类产品的竞争。要实现清远市漂流旅游的可持续迅速发展,需要做好清远漂流旅游品牌整体形象的塑造、多功能综合性漂流旅游区的建设、漂流旅游安全管理、从业人员的总体素质、对外宣传营销以及漂流旅游发展的总体规划等六方面的工作。     

Pseudo-feathery dunes in the Kumtagh Desert

The Kumtagh Desert is the last explored desert in China. The unique patterns on aerial photographs and satellite images have led previous researchers to the conclusion that the Kumtagh Desert is the only place over the world where typical feathery dunes are developed, and that some unique wind regimes are at work. Recent field investigation reveals that the feathery patterns in fact reflect the albedo contrasts between the seif dunes, bright dune-like drifts and the dark inter-dune lag sediments. The wind regime in the area containing the so-called feathery dunes is typical of the regime that produces seif dunes that were considered to be shafts of the feathery dunes, and the vanes of the feathery dunes are in fact bright dune-like drifts with indistinct height from the surroundings rather than true transverse dunes. Further analysis indicates that the sediments of seif dunes, dune-like drifts and dark inter-dune flats differ in grain size distribution, mineralogy, reflectance spectrum and particle micro-morphology. Sediments that constitute seif dunes and dune-like drifts are finer and poorly rounded, contain relatively more quartz, and hence have higher albedo, while the sediments that constitute the dark inter-dune flats are coarser and better rounded, contain far less quartz but relatively more andesite and dacite, and hence have lower albedo. As a result, what was originally perceived as unique feathery dunes are in fact only pseudo-feathery dunes composed primarily of seif dunes. This discovery also demonstrates that blowing sand drifts can form dune-like patterns that remain visible for long periods of time. It is important to distinguish between the patterns of true dunes and those of dune-like drifts (pseudo-dunes) that cause albedo contrasts in interpreting remote sensing images.     

航海图书编辑系统设计与实现

在简要分析航海图书编辑设计和海图生产流程管理现状的基础上,详细论述了航海图书编辑系统的结构、功能和数据库建设,设计了基于ArcEngine的资料可视化分析和示意图制作,实现了海图生产流程的电子审批与管理,归纳了系统开发的关键技术。     

基于旅游需求的广西入境旅游时空变化研究

以广西入境旅游为研究对象,从旅游需求的角度出发,通过地理集中指数、年际集中指数、亲景度和旅游流等指标对广西入境旅游的时窄变化进行分析,总结了广西入境旅游的时空变化特征.按照对旅游目的地国际游客从来源到流向的分析思路,首先对广西入境旅游的时空集中性和亲景度进行分析,提出根据亲景度和年际集中指数对主要客源市场进行有重点、分层次开发.其次通过入境游客在广西区内的流向分析,指出应在把握游客需求趋势的基础上,促进优势旅游资源的开发和空间布局的优化.     

Spatio-temporal patterns of land use change along the Bohai Rim in China during 1985–2005

Based on TM image data and other survey materials, this paper analyzed the spatiotemporal patterns of land use change in the Bohai Rim during 1985–2005. The findings of this study are summarized as follows: (1) Land use pattern changed dramatically during 1985–2005. Industrial and residential land in urban and rural areas increased by 643,946 hm2, of which urban construction land had the largest and fastest increase of 294,953 hm2 at an annual rate of 3.72%. (2) The outward migration of rural population did not prevent the expansion of residential land in rural areas by 184,869 hm2. This increase reveals that construction of rural residences makes seriously wasteful and inefficient use of land. (3) Arable land, woodland and grassland decreased at a rate of –0.02%, –0.12% and –1.32% annually, while unused land shrank by 157,444 hm2 at an annual rate of –1.69%. (4) The change of land use types showed marked fluctuations over the two stages (1985–1995 and 1995–2005). In particular, arable land, woodland and unused land experienced an inversed trend of change. (5) There was a significant interaction between arable land and woodland. Industrial construction land in urban and rural areas showed a net trend of increase during the earlier period, but only adjustment to its internal structure during the second period. The loss of arable land to the construction of factories, mines and residences took place mainly in the fringe areas of large and medium-sized cities, along the routes of major roads, as well as in the economically developed coastal areas in the east. Such changes are closely related to the spatial differentiation of the level of urbanization and industrialization in the region.     

南极中山站站区上空气溶胶金属成分特征研究

连续三年(1998-2001年)采集了南极中山站的气溶胶样品,利用中子活化(INAA)分析其元素组成,采用作图法对元素的来源进行分析。结果表明除南极中山站气溶胶中的Na,Cl,Mg,Ca,Sr,Br,I和Rb等8个元素主要来自海洋,Al,Sc,Fe和Mn等4个元素主要来自陆源,而Se,Co,Sb,Zn和Cr等5个元素呈现出高度的富集,属于重金属污染特征元素,这可能与站区发电、垃圾焚烧、污水处理、车辆运行和加工制作等站务活动有关。     

城市交通网络的多尺度地理信息系统数据建模

多模式交通是未来城市交通的重要形式,多模式交通系统要求每个交通模式平衡发展并发挥其最好的服务性能。可靠的数据和信息获取是建立可持续多模式交通系统的基础。单一模式的交通地理信息系统信息模型不能准确地反映城市交通空间网络的特性和联系程度。针对此问题,提出一种面向多尺度多模式的城市交通网络地理信息系统数据模型,支持多模式交通网络地理数据集成化和拓扑关系模型化,实现多模式交通数据的综合分析和表达。数据模型在概念和逻辑建模层面上,应用面向对象设计语言及其扩展机制集成面向地理信息时空特征描述的可视化语言插件(plug-in for visual languages,PVL),将不同交通线网集成于一个综合信息模型中。交通线网的多尺度表达允许不同的交通地理信息系统应用和专业化信息服务的开发和实现,辅助多模式交通网络规划和发展,并且进一步优化城市交通的应用。将模型应用在广州市多模式交通系统中进行可靠性和实用性验证,对未来相关的研究和应用具有指导意义。