The Potential of Maps APIs for Internet GIS Applications

Since the launching of Maps Application Programming Interfaces (APIs) in 2005, many web developers, including geographers and non‐geographers, applauded the freely adaptable tools and used them to spawn numerous Internet applications. The success of the Maps APIs is largely attributable to its no‐cost policy, the availability of global data coverage, dynamic navigation, query capability, and ease of implementation. Despite its versatility in dynamic exploration of geographic data online, the existing Maps APIs lack Geographic Information System (GIS) functionalities compared to other Internet Mapping Services. The goal of this research was to review the potential of the Maps APIs for Internet GIS applications. This research employed the Google Maps API and developed a web prototype that disseminates spatial information of urban sprawl in Mundy Township, Michigan. The results revealed that both vector and raster data could be effectively represented by using the Maps API. Moreover, the Geographic Markup Language (GML) approach illustrated great potential for developing Internet GIS solutions around open specifications. This research suggested several potential solutions to expand the spectrum of GIS operations of the Maps APIs by incorporating the XML‐related technology and extending the JavaScript library.     

电子地图中多尺度地图数据显示的研究

将计算机三维模型简化中的LOD思想引入到电子地图的组织和显示中,提出了同一比例尺数字地图不同详细程度的分层显示方法和不同比例尺数字地图嵌套显示方法,实现了电子地图的多级缩放。     

Quadrature-based approach for the efficient evaluation of surge hazard

The Joint Probability Method (JPM) has been used for hurricane surge frequency analysis for over three decades, and remains the method of choice owing to the limitations of more direct historical methods. However, use of the JPM approach in conjunction with the modern generation of complex high-resolution numerical models (used to describe winds, waves, and surge) has become highly inefficient, owing to the large number of costly storm simulations that are typically required. This paper describes a new approach to the selection of the storm simulation set that permits reduction of the JPM computational effort by about an order of magnitude (compared to a more conventional approach) while maintaining good accuracy. The method uses an integration scheme called Bayesian or Gaussian-process quadrature (together with conventional integration methods) to evaluate the multi-dimensional joint probability integral over the space of storm parameters (pressure, radius, speed, heading, and any others found to be important) as a weighted summation over a relatively small set of optimally selected nodes (synthetic storms). Examples of an application of the method are shown, drawn from the recent post-Katrina study of coastal Mississippi.     

基于Google Maps API的船舶自动站监控Web设计

简要介绍了Google Maps JavaScript API技术,并着重阐述了其作为主流的WebGIS技术在船舶自动气象站监控页面设计中的应用,包括：通过JavaScript和AJAX技术请求远程数据服务器获取气象数据、状态数据及GIS信息等,并将返回的JOSN格式数据加载到Google Map上,同时通过Google Maps JavaScript定制化船舶图标并对加载的船舶轨迹进行渲染,使用户需要的监控信息更加直观地显示在监控页面上。本文结果已成功应用到广东省气象局设备全网监控系统之中。     

Links between Arctic sea ice and extreme summer precipi- tation in China：an alternative view

Potential links between the Arctic sea-ice concentration anomalies and extreme precipitation in China are explored. Associations behind these links can be explained by physical interpretations aided by...     

Topodata: Brazilian full coverage refinement of SRTM data

This work presents the selection of a set of geostatistical coefficients suitable for a unified SRTM data refinement from 3″ to 1″ through kriging over the entire Brazilian territory. This selection aimed at data potential for geomorphometric derivations, given by the preservation of detailed geometric characteristics of the resulting digital elevation models (DEM), which are sensitive to refining procedures. The development contained a long-term experimentation stage, when data refinement through kriging was locally developed to support distinct regional projects, followed by a unified selection stage, where the acquired experience was applied to select a single and unified interpolation scheme. In this stage, the selected geostatistical models with promising performances were tested for unified refinement on 40 Brazilian areas with distinct geological settings. Tested areas encompass reliefs varying from mountainous to plain. The effects of data preparation were observed on the perception of patterns (texture and roughness), as well as of singularities (edges, peaks, thalwegs etc.). Results were evaluated mainly through the examination of shaded reliefs, transects and perspectives observed in different scales. Terrains with low slopes and small amplitudes had their DEM promptly affected by the refining methods, as opposed to mountainous terrains. The evaluation, unambiguously confirmed by all consulted interpreters, converged into a refining model with outstanding performance in all tested conditions.     

分布式地震应急救援态势标绘系统

地震现场救援要素众多,部署分散,为了统一管理救援要素,综合展示救援态势,设计一种基于B/S架构的地震应急救援态势标绘系统,采用Google Maps API v3实现前端Web GIS功能,加载谷歌地图,标绘震情灾情和救援要素信息,通过AJAX方式与服务器端进行数据交互,保存要素信息或者获取服务器端数据,系统设计聊天室功能,登录用户可以在线实时交流。本系统对使用环境要求低,支持多种移动终端,适合地震现场人员使用,实现了分布式要素标绘功能,是地震现场救援行动的有效辅助决策工具。     

极地空间信息平台的设计与实现

提出利用Google Maps API结合Ajax技术建立空间平台管理极地数据信息,阐述设计原理及优势,并编程进行了平台实现。平台利用空间数据库统一管理空间信息和属性信息,提高信息共享程度,改善信息浏览体验,更好地服务于极地科学考察。     

基于百度地图的自动气象站监控系统实现

设计了一种基于百度地图JavaScript API的自动气象站监控系统,系统页面通过区域重绘、图标定制、要素切换等效果直观显示自动气象站的状态及实时数据,极大地方便了用户对自动气象站的监控。通过AJAX技术请求远程SQL数据库获取站点状态数据及气象数据,避免了Baidu Maps的不断加载而导致页面速度较慢的问题,并使用百度地图第3方类函数扩展监控页面显示效果。该设计已成功应用于广东省气象台站大气综合监测业务共享集群平台中。     

Measuring the attractiveness of Dutch landscapes: Identifying national hotspots of highly valued places using Google Maps

In a Cost-Benefit Analysis (CBA) or an Environmental Impact Assessment (EIA), determining the value that the general public attaches to a landscape is often problematic. To aid the inclusion of this social value in such analyses, a Google Maps-based tool, called the HotSpotMonitor (HSM), was developed. The HSM determines which natural places are highly attractive by having people mark such places on a map. The definition of attractiveness remains open to avoid having marker placement being influenced by preconceived thoughts. The number of markers an area receives is considered to indicate its social value. Six regions were selected, and from these, stratified samples were drawn (total n = 3293). Participants placed markers at three spatial levels: local, regional and national. This paper focuses on the markers at the national level. The first research question is whether the HSM can produce an accurate map of highly attractive places at a national level. The results indicated that while in principle HSM can produce such a map, the spatial representativeness of the sample is important. The region of origin of the participants influenced where they placed their markers, an effect previously termed spatial discounting. The second research question considers which qualities the participants associate with the marked places. These qualities were very similar at all three spatial levels: green, natural, presence of water and quiet were often selected out of the fourteen suggested qualities. The third, and more exploratory, research question concerns which characteristics of an area predict its attractiveness. Natural and forest areas had higher marker densities than water surfaces or all other types of land use combined. The discussion evaluates the potential of the HSM to generate input on social landscape values for CBAs and EIAs.