Virtual Geographic Information System Research Articles

Integrating Virtual Reality and GIS Tools for Geological Mapping, Data Collection and Analysis: An Example from the Metaxa Mine, Santorini (Greece)

In the present work we highlight the effectiveness of integrating different techniques and tools for better surveying, mapping and collecting data in volcanic areas. We use an Immersive Virtual Reality (IVR) approach for data collection, integrated with Geographic Information System (GIS) analysis in a well-known volcanological site in Santorini (Metaxa mine), a site where volcanic processes influenced the island’s industrial development, especially with regard to pumice mining. Specifically, we have focused on: (i) three-dimensional (3D) high-resolution IVR scenario building, based on Structure from Motion photogrammetry (SfM) modeling; (ii) subsequent geological survey, mapping and data collection using IVR; (iii) data analysis, e.g., calculation of extracted volumes, as well as production of new maps in a GIS environment using input data directly from the IVR survey; and finally, (iv) presentation of new outcomes that highlight the importance of the Metaxa Mine as a key geological and volcanological geosite.

WITHDRAWN

The document associated with this DOI has been withdrawn.

Use of GIS and Remote Sensing Technology as a Decision Support Tool in Flood Disaster Management: The Case of Southeast Louisiana, USA

The primary objective of this paper was to identify flood-prone areas in Southeast of Louisiana to help decision-makers to develop appropriate adaptation strategies and flood prediction, and mitigation of the effects on the community. In doing so, the paper uses satellite remote sensing and Geographic Information System (GIS) data for this purpose. Elevation data was obtained from the National Elevation Dataset (NED) produced by the United States Geological Survey (USGS) seamless data warehouse. Satellite data was also acquired from USGS Earth explorer website. Topographical information on runoff characteristics such as slope, aspect and the digital elevation model was generated. Grid interpolation TIN (triangulated irregular network) was carried from the digital elevation model (DEM) to create slope map. Image Drape was performed using ERDAS IMAGINE Virtual GIS. The output image was then draped over the NED elevation data for visualization purposes with vertical exaggeration of 16 feet. Results of the study revealed that majority of the study area lies in low-lying and very low-lying terrain below sea level. Policy recommendation in the form of the need to design and build a comprehensive Regional Information Systems (RIS) in the form of periodic inventorying, monitoring and evaluation with full support of the governments was made for the study area.

VGIS-AntiJitter: an effective framework for solving jitter problems in virtual geographic information systems

With the proposition of the Digital Earth (DE) concept, Virtual Geographic Information System (VGIS) has started to play the role of a Digital Earth prototype system. Many core problems involved in VGIS, such as out-of-core management and interactive rendering of very large scale terrain and image data, have been well studied in the past decades. However, the jitter problem, a common problem in VGIS that often causes annoying visual artefacts and deteriorates the output image quality, draws little attention. In this paper, after an intensive analysis of the jitter problem, a comprehensive framework is proposed to address such a problem while accounting for the characteristics of different data types in VGIS, such as terrain or ocean mesh data, vector data and 3-D model data. Specifically, this framework provides an improved dynamic local coordinate system (DLCS) method for terrain or ocean mesh data. For vector data, the framework provides a simple and effective multiple local coordinate systems (MLCS) method. The framework provides a MLCS method for 3-D model data making full use of the existing local coordinate system of the model. The advantages of the proposed methods over current approaches are analysed and highlighted through case studies involving large GIS datasets.

3D visualizing of volumetric surface movement at karstic limestone area

Limestone bedrock topography has complex phenomena and highly relief subsurface topography due to the presence of karstic features. Geotechnical and environmental problems arise whenever foundations are established on the surface of the limestone bedrock or within the overburden soils. Geographical information system (GIS) and remote sensing are emerging as powerful techniques widely applicable in natural resources management to detect land use changes and devise strategies based on these changes. The study focuses on using aerial photography for the detection of changes and effects of mining on geomorphology, especially the use of sequential images that allows to detect changes taken place from time to time, by using. Volumetric Surface Movement Spatiotemporal Data Model (VSMSDM) application has been employed to create karst terrain surface movements and visualized 3D information in the Virtual Geographical Information Systems (VGIS). VSMSDM application was implemented by developing prototype of visualization system using with integrated time in the TIN structure. The data have been collected from aerial photography in 1981 and 2004, and the results displayed that the proposed data model is able to view the changing in karst topography to detect significant landscapes and landforms changes.

VGIS-COLLIDE: an effective collision detection algorithm for multiple objects in virtual geographic information system

Collision detection is an important component in simulation applications which are based on virtual geographic information system (VGIS). In this paper, an effective collision detection algorithm for multiple objects in VGIS, VGIS-COLLIDE, is presented. The algorithm firstly integrates existing quadtree, which is the global hierarchical structure of VGIS, with axis-aligned bounding box of object to perform the broad-phase of collision detection. After that, exact collision detection between two objects which have passed the broad-phase of collision detection is performed. The algorithm makes no assumption about input primitives or object's motion and is directly applicable to all triangulated models. It can be applicable to both rigid and deformable objects without preprocessing. The performance of the algorithm has been demonstrated in several environments consisting of a high number of objects with hundreds of thousands of triangles.

Visualisation for Participatory Coastal Zone Management: A Case Study of the Norfolk Coast, England

It is widely recognised that organisations involved in coastal management must take steps to improve the ways in which stakeholders and the public are involved in coastal decision-making. In particular, there needs to be more emphasis on improving participation, consultation, and information provision throughout the process. In recognition of this, there is a need to develop new techniques that could aid the communication of coastal information to the public. It has been suggested that some of these techniques might involve the use of Geographical Information Systems (GIS). Whilst GIS are widely used by coastal managers, their application is hampered by the highly technical output that they often produce. However, the advent of a new type of system known as virtual reality GIS enables the likely effects of coastal management decisions to be presented in a format that is suitable for widespread consultation and dissemination. A proposed managed realignment scheme on the north Norfolk coast, England, is used to describe an integrated GIS methodology allowing the production of virtual reality representations of the current site environment and simulations of what might be present after the intervention. Both static and user-navigable visualisations have been produced because these lend themselves to both paper and electronic publication. Comparisons between the alternative methods are presented along with a discussion of the technical, user, and institutional issues surrounding the potential application of the methodology. It is argued that the techniques presented have the potential to stimulate meaningful discussion during the consultation process, although further research is still required to determine the exact form this might take.

A Java/CGI approach to developing a geographic virtual reality toolkit on the Internet

A Java/common gateway interface (CGI) approach is employed to design a toolkit for interactively building up virtual environments from existing geographical information system (GIS) databases. This approach takes advantage of both the Java and CGI approaches, providing a flexible and user friendly interface, while making better use of the power of the server. It is also beneficial to the balancing of workloads on both client and server sides. A prototype, called GeoVR, has been implemented by extending ArcView Internet Map Server on its client side by the Java language and correspondingly, on its server-side by the Avenue language. The GeoVR server is responsible for generating 3D scenes in terms of parameter values sent from the Java client. The 3D scenes are then transformed to VRML models, and delivered to the WWW browser for display and navigation. This toolkit, allowing users to interact with 2D GIS data on the Internet and create perspective views from these data on the fly, illustrates how to extend an existing Internet GIS into a more powerful virtual GIS.