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Flood visualization is an effective and intuitive tool for representing flood information from abstract spatiotemporal data. With the growing demand for flood disaster visualizations and mitigation...

Collaborative geoprocessing models have become one of the major solutions to significantly enhance the capacity to derive knowledge over a network, which are critical for the support of comprehensive analyses in a virtual geographic environment (VGE). With the emergence and growing maturity of the cloud computing infrastructure, a cloud-based platform for collaborative geoprocessing models promises to provide a pattern for the next generation of geoprocessing collaboration in the GIS realm. However, the problems with the existing collaborative geoprocessing models remain numerous, including the following: heterogeneity in description specifications hinders different geoprocessing services in collaborative work; the heterogeneity in messages mechanisms makes the cooperation among the geoprocessing services difficult and an integrated geoprocessing model framework centring on the collaborative model’s lifecycle is absent. To address these problems, this article proposes a cloud-based framework for building,...

With the two cores of database and model-base, Virtual Geographic Environment (VGE) breaks the limitations of the traditional Geographic Information System (GIS), which provides new support to the study and understanding of our world. [...]

Emergency risk assessment of debris flows in residential areas is of great significance for disaster prevention and reduction, but the assessment has disadvantages, such as a low numerical simulation efficiency and poor capabilities of risk assessment and geographic knowledge sharing. Thus, this paper focuses on the construction of a VGE (virtual geographic environment) system that provides an efficient tool to support the rapid risk analysis of debris flow disasters. The numerical simulation, risk analysis, and 3D (three-dimensional) dynamic visualization of debris flow disasters were tightly integrated into the VGE system. Key technologies, including quantitative risk assessment, multiscale parallel optimization, and visual representation of disaster information, were discussed in detail. The Qipan gully in Wenchuan County, Sichuan Province, China, was selected as the case area, and a prototype system was developed. According to the multiscale parallel optimization experiments, a suitable scale was chosen for the numerical simulation of debris flow disasters. The computational efficiency of one simulation step was 5 ms (milliseconds), and the rendering efficiency was approximately 40 fps (frames per second). Information about the risk area, risk population, and risk roads under different conditions can be quickly obtained. The experimental results show that our approach can support real-time interactive analyses and can be used to share and publish geographic knowledge.

In traditional geological field practice (GFP), there are many problems, such as waste of human and material resources, dispersion of geological phenomenon and failure to reproduce geological processes, which lead to the inefficiency of traditional education. Recently, virtual geographic environment (VGE) has become increasingly popular. It can provide us an immersive, interactive and collaborative three-dimensional (3D) multi-user virtual environment which can help us to solve the above problems. In this paper, we present a Virtual Geological Field Practice System (VGFPS) for Huyu Region based on OpenSimulator, an open source virtual world server which can be used to create VGEs. VGFPS integrates texts, images, videos and other multimedia with digital elevation models (DEMs), remote sensing (RS) images, buildings and landscapes, geological process simulation models and in-world scripts to enable teachers and students to explore, navigate, interact in virtual environment and communicate, collaborate with each other. Practices show it’s feasible to use VGEs to make GFP education more effective and it can be applied to the domain of virtual education.

It takes cooperation among multi-user in virtual geographic environment (VGE) based on Multi-Agent System (MAS) in the centralized system as researched object. Then we detailed analyze and research arithmetic of collectivistic operating behaviour learning of Multi-Agent based on Genetic Algorithm (GA). Finally we design an example which shows how 3 evolutional Agents cooperate to complete the task of colony pushing cylinder box.

We propose a novel method for the automated generation of virtual geographic environments that allows using geographic information system data to build what we call informed virtual geographic environment (IVGE). The description of an IVGE integrates semantic information expressed using conceptual graphs, a standard knowledge representation technique. In addition, we propose an abstraction process that uses geometric, topologic, and semantic characteristics of geographic features to build a hierarchical graph-based structure describing this IVGE. Our IVGE model enables the support of large-scale and complex geographic environment modeling for multiagent geo-simulations in which the agents are situated and with which they interact.

Dam-break flood affected by highly changing and complex environment, has some characteristics including the sudden of occurrence, the rapid of expansion and the urgency of respond. This paper focuses on how to develop a virtual geographic environment (VGE) system to study the dam-break flood routing and its impact. Unlike existing work, our methods pay attention to the multidimensional and dynamic analysis methods in virtual geographic environment, which make flood routing easily understood to public and officers. Moreover, some GIS spatial analysis and real-time interactive operation with the VGE will also be implemented to support the risk assessment of the dam-break. Finally, a prototype system is developed to construct a virtual geographic environment for impact analysis of dam-break flood routing and dynamic interaction. Experimental results prove that the scheme addressed in the paper is effective and feasible.

Previous research on the Virtual Geographic Environment (VGE) has focused mainly on representation rather than geographic analysis. However, geographic analysis plays a significant role in modern geography. To address this issue, this paper systematically examines theories and implementing VGE techniques that support geographical analysis and simulation. Based on its framework, VGE can be divided into four subtypes. These are the data environment, modeling environment, expression environment, and collaborative environment. The functions and key techniques of each are examined, and some case studies are discussed. This study provides direction for necessary new developments of advanced VGE platforms.

We propose a framework to reason qualitatively about courses of action (COAs) which need to be executed in a realistic geographic space that may change. Particularly, the framework aims to support human mental 'What-If' analysis by simulating the execution of COAs in a virtual geographic environment, which can change during the simulation, and by allowing the user to explore various scenarios (different COAs) and to analyse their outcomes using causal reasoning techniques. In this article, we first present a framework which is based on a conceptual model of spatio-temporal situations, a multi-agent geosimulation platform and qualitative spatio-temporal causal reasoning techniques. Then, we illustrate the framework using a case study.

The geographical environment with low-altitude is complex. Ground mountain, tall buildings, communications tower, bridge across the river, the tall vegetation has a significant effect on low altitude fly. The technology of virtual navigation and collision warning system which based on satellite navigation and virtual geographic environment is an important technical guarantee for safety fly in low-altitude space. This paper analysed the characteristic of low-flying environment and its impact on safe flight. And designed a global virtual geographic environment data organization model based on global discrete three dimensional grid model combining with object-oriented data organization model. The way of subdivision, coding and object organization has been discussed, then designed the structure of the object in the model in low attitude environment. At last an algorithm for low-flying anti-collision warning was designed to prove use of this model.

On the basis of previous work, this paper designs an intelligent agent based on virtual geographic environment (VGE) system that is characterized by huge data, rapid computation, multi-user, multi-thread and intelligence and issues challenges to traditional GIS models and algorithms. The new advances in software and hardware technology lay a reliable basis for system design, development and application.

Public health decision makers need to better understand the propagation of zoonoses. The currently available zoonosis simulations are based on compartment models which do not integrate the influence of geographic features on the species’ biological processes. In this context, we propose an approach that can generate an informed virtual geographic environment (IVGE) composed of a set of cells in which the evolution and interaction of the involved populations can be simulated plausibly. Since the number of these cells is huge, we propose a threshold-based merging algorithm that creates spatial subdivisions with the maximal size and suitability for a given biological phenomenon. Our approach also enhances each cell with qualitative and quantitative information such as the relative geographic orientation of the neighbors and the information about the distribution of individuals through trajectories. We used our IVGE to develop decision support tools that can simulate the spread of the West Nile Virus and Lyme disease.

The model environment is a key component that enables a virtual geographic environment (VGE) to meet the scientific requirements for simulating dynamic phenomena and performing analyses. Considering the comprehensiveness of geographic processes and the requirements for the replication of model-based research, this paper proposes a model base framework for a model environment of a VGE that supports both model construction and modelling management, resulting in improved reproducibility. In this framework, model management includes model metadata, creation, deposition, encapsulation, integration, and adaptation; while modelling management focuses on invoking the model, model computation, and runtime control of the model. Based on this framework, to consider the problem of ever-worsening air quality, we applied the Linux-Apache-MySQL-Perl stack plus Supervisor to implement the model base to support a VGE prototype using professional meteorological and air quality models. Using this VGE prototype, we simulated a typical air pollution case for January 2010. The prototype not only illustrates how a VGE application can be built on the proposed model base, but also facilitates air quality simulations and emergency management.

Large volumes of uraniferous gold tailings deposited over more than a century in densely populated metropolitan areas of South Africa (SA) pose potential health hazards to millions of residents of nearby settlements, including many vulnerable, impoverished populations. In order to inform the selection of suitable sampling populations for epidemiological studies a mapping methodology based on a Virtual Geographic Environment (VGE) combined with a Geographical Information System (GIS) was developed. The structure, architecture and database of the system are presented.

Multi-Agent Geo-Simulation (MAGS) is a modelling and simulation paradigm which involves a large number of autonomous situated agents of various extents evolving in, and interacting with, an explicit description of a geographic environment called a Virtual Geographic Environment (VGE). One of the most important skills of autonomous situated agents is their ability to navigate and plan a path inside a VGE. Path planning in MAGS has to be solved in real time, often under constraints of limited memory and CPU resources. Moreover, the computational cost of path planing increases in complex and large-scale VGEs. In addition, most current planners only provide agents with obstaclefree paths and do not take into account the environments' topologic and semantic characteristics nor the agents' capabilities. In this paper, we extend the automated approach to build a semantically-enhanced and geometrically-accurate VGE called an Informed VGE (IVGE) that we proposed in [21]. Then, we propose our Hierarchical Path Planning (HPP) algorithm which relies on the topologic graph of the IVGE, and takes advantage of this IVGE's semantically-enriched description in order to provide autonomous situated agents with optimised paths with respect to both the environment's and the agents' characteristics.

Virtual Geographic Environment (VGE) technique derives from Geographic Information Systems (GIS) and Virtual Reality (VR). A VGE represents three dimensional geographic data, to target visualisation as well as simulation applications. It is generally built upon a grid-based representation which raises the well-known problems of localised data accuracy and multiple data merging. In this paper we propose a novel approach of VGE using a topological model. This approach provides an exact representation of GIS data, allowing an accurate geometrical exploitation. Moreover, our model can merge and represent several semantic information, even if spatially overlapping. Finally, we illustrate this model with a VGE application which is able to automatically extract the required data from standard GIS files, and which then allows to navigate and retrieve information from the computed VGE.

The rapid economic development of the PRD (Pearl River delta) has led to severe air pollution. Air pollution control is critical for sustainable development. From a geographic viewpoint, this paper will focus on how to develop a virtual geographic environment (VGE) to study environmental issues. Unlike existing work, our methods pay attention to dynamic 3D volume representation in virtual PRD terrain environment, which make air pollution transportation and dispersion easily understood to public and officers. Moreover, some GIS spatial analysis and real-time interactive operation with VGE will also be implemented to support the management and control of atmospheric pollution. A prototype system is developed to construct a virtual geographic environment for simulating the PRD region air pollution and dynamic interaction. Experimental results prove that the scheme addressed in the paper is effective and feasible.

In this paper we propose an approach to support "what-if" analysis in the context of COA evaluation. Our approach consists in using multiagent geosimulation to simulate the execution of COAs in a Virtual Geographic Environment (VGE) which can change during the simulation, and then allowing the user to explore various assumptions and to analyse their outcomes. We identify the requirements to support this approach and we present how we implement them in the MAGS-COA software. We also illustrate our approach on an example and we present future works.

Evaluation is an important content in the study of VGE (Virtual Geographic Environment) and through all the study process. This paper constructs an evaluation framework for VGE, and discusses the reality, immersion and usability. We propose 3 balances as the evaluation degrees and 2 comparisons as the content of evaluation. Then we categorize the immersion into 4 levels and give 4 components of the influence on immersion. At last we evaluate the advantages and disadvantages of VGE and conclude the tasks unfit for VGE. The 3D images in the simulation of VGE can offer users a strong visual shock as they are personally on the scene. People always regard it as a mark of new technique and fashion and strive to make all images into 3D ones [1]. In order to clarify such notion, it is necessary to confine its application scientifically and objectively and research its evaluation standard. So, evaluation is an important content in the study of VGE and should be through all the study process. In our opinion, all the good techniques and methods will be useless without regarding evaluation framework and repeatedly tested principles of application. The evaluation framework for VGE (as shown in Figure 1) constructed in this paper attempts to research into it from 3 aspects.