通用电子地图符号库的研制

无论是纸质地图还是电子地图,地图符号库均是它们的重要组成部分。从当前电子地图符号库存在的问题出发,详细叙述了基于用户的通用电子地图符号库的研制过程,最后简述了其实现方法及功能。实验结果表明,研制的电子地图符号库不仅符合用户的视觉感受,而且完全符合电子地图的显示要求。     

智慧管廊综合管理平台的建设及应用

随着智慧城市的发展,地下综合管廊的建设不断增多,建成后的管廊需要有科学合理的综合管理平台对其进行智能化管理.本文介绍了地下综合管廊的建设内容,从管廊智能化管理角度出发,在运用GIS、可视化、传感器、物联网等多种技术的基础上,搭建起智慧管廊综合管理平台,为实现管廊的安全管理提供有力保障.     

Exploratory analysis of the interrelations between co-located boolean spatial features using network graphs

Visual data mining of spatial data is a challenging task. As exploratory analysis is fundamental, it is beneficial to explore the data using different potential visualisations. In this article, we propose and analyse network graphs as a useful visualisation tool to mine spatial data. Due to their ability to represent complex systems of relationships in a visually insightful and intuitive way, network graphs offer a rich structure that has been recognised in many fields as a powerful visual representation. However, they have not been sufficiently exploited in spatial data mining, where they have principally been used on data that come with an explicit pre-specified network graph structure. This research presents a methodology with which to infer relationship network graphs for large collections of boolean spatial features. The methodology consists of four principal stages: (1) define a co-location model, (2) select the type of co-association of interest, (3) compute statistical diagnostics for these co-associations and (4) construct and visualise a network graph of the statistic from step (3). We illustrate the potential usefulness of the methodology using an example taken from an ecological setting. Specifically, we use network graphs to understand and analyse the potential interactions between potential vector and reservoir species that enable the propagation of leishmaniasis, a disease transmitted by the bite of sandflies.     

地质结构面与地表及坑探工程斜面水平投影图编制

地表及坑探工程素描图是描述各种地质现象的最基础图件,建立空间概念、掌握任意地质结构面与任意斜面之间的组合关系是正确绘制上述图件的关键。运用图解与计算相结合的手法就不同产状地质结构面在任意斜面水平投影图上的表现特征进行对比,提出了地质结构面视走向与视走向线的概念,阐述地质结构面视走向与地质结构面产状、斜面坡向及坡角之间的关系及其在地表及坑探工程斜面水平投影图编制中的应用。     

Spatial Distribution of Seismic Landslides in the Areas of 1927 Gulang M8.0 Earthquake

The 1927 Gulang M8.0 earthquake has triggered a huge number of landslides, resulting in massive loss of people''s life and property. However, integrated investigations and results regarding the landslides triggered by this earthquake are rare; such situation hinders the deep understanding of these landslides such as scale, extent, and distribution. With the support of Google Earth software, this study intends to finish the seismic landslides interpretation work in the areas of Gulang earthquake (VIII-XI degree) using the artificial visual interpretation method, and further analyze the spatial distribution and impact factors of these landslides. The results show that the earthquake has triggered at least 936 landslides in the VIII-XI degree zone, with a total landslide area of 58.6 km². The dense area of seismic landslides is located in the middle and southern parts of the X intensity circle. Statistical analysis shows that seismic landslides is mainly controlled by factors such as elevation, slope gradient, slope direction, strata, seismic intensity, faults and rivers. The elevation of 2 000-2 800 m is the high-incidence interval of the landslide. The landslide density is larger with a higher slope gradient. East and west directions are the dominant sliding directions. The areas with Cretaceous and Quaternary strata are the main areas of the Gulang seismic landslides. The X intensity zone triggered the most landslides. In addition, landslides often occur in regions near rivers and faults. This paper provides a scientific reference for exploring the development regularities of landslides triggered by the 1927 Gulang earthquake and effectively mitigating the landslide disasters of the earthquake.     

Design and evaluation of a geovisual analytics system for uncovering patterns in spatio-temporal event data

ABSTRACT

It remains difficult to develop a clear understanding of geo-located events and their relationships to one another, particularly when it comes to identifying patterns of events in less-structured textual sources, such as news feeds and social media streams. Here we present a geovisualization tool that can leverage computational methods, such as T-pattern analysis, for extracting patterns of interest from event data streams. Our system, STempo, includes coordinated-view geovisualization components designed to support visual exploration and analysis of event data, and patterns extracted from those data, in terms of time, geography, and content. Through a user evaluation, we explore the usability and utility of STempo for understanding patterns of recent political, social, economic, and military events in Syria.     

视觉认知的自适应多级岛屿群空间模式提取

针对当前电子地图显示范围以及人眼视觉分辨能力的限制,该文提出了符合视觉认知规律的自适应多级岛屿群空间模式,基于动态邻近图、最小生成树、最小面积外接矩形等概念设计了岛屿群多级空间模式提取算法。实验结果表明,该方法有效顾及了岛屿群显示的空间尺度,能够自适应地生成符合显示尺度要求的岛屿群多级空间模式,提高了空间模式识别的灵活性和有效性。     

保持视觉特征的lod模型简化算法研究

在考虑不严重影响画面视觉效果的前期下提出了保持视觉特征的lod模型简化算法该方法能较好地解决复杂地形场景模型引起的绘制视觉失真问题 在保持视觉特征的前提下引入顶点的曲度特征因子通过限制狭长三角形的生成和标记色差明显的三角形很好地保证了模型的几何和纹理特征 通过计算折叠代价的方法减少模型误差累积有效地解决了影响视觉效果的问题 实验结果表明在保证视觉特征的前提下利用半边折叠算法简化模型实现三维场景的地形绘制     

Community volunteer assessment of recreational water quality in the Hutt River,Wellington

ABSTRACT

Water is an important component of many recreational opportunities and New Zealand invests significant resources in recreational water quality (RWQ) monitoring to assess risks to public health. However, monitoring primarily focuses on microbiological hazards and RWQ is considerably broader than this. The goal of this study was to take a comprehensive approach to evaluating RWQ while exploring the potential for greater public involvement in monitoring. A popular river swimming site was co-monitored weekly by volunteers and a council field officer. The attributes monitored–water temperature, visual clarity, benthic cyanobacteria and filamentous periphyton cover, E. coli and rubbish–were identified from a volunteer workshop. There was good concordance between volunteer and council data suggesting that volunteer measurements can be considered reliable. This highlights the potential for volunteers, with professional support, including training and quality assurance, to extend council RWQ surveillance to additional monitoring sites while improving public engagement on water management.