Modeling and Visualization for Spatial Decision Support
Suzana Dragićević

Prior research endeavors in the disciplines of spatial modeling and visualization have developed primarily along parallel streams. This is inadequate because geographic problems are too complex to yield reliable solutions from each discipline alone. Innovative theories and new technologies are now providing greater opportunities in Geographic Information Science research to embed spatial modeling and visualization concepts into spatial decision support systems. Improvements in spatial representation formalisms and computational processing capabilities have influenced how geographic problems are described, visualized, and modeled in space and time. One drawback, however, is that existing models and analytical approaches, as well as cutting-edge geo-visual interfaces and tools, are often purely theoretical or are developed for hypothetical or non-real data. Hence, they can be viewed as toys for developing “what if?” scenarios (Couclelis 2005). This critique can be addressed by situating the spatial decision support system in a real-world context and rigorously evaluating its outcome. Consequently, specific implementations of such spatial decision support systems as planning support systems, spatial understanding and decision support systems, and collaborative GIS have emerged (Balram and Dragićević 2006).

Spatial decision support systems can be considered as praxeology component of GIScience because they represent a combination of computer-based tools that use geospatial data in semi-structured frameworks to improve real-world decision-making. When the spatial decision support system is not rooted in the realities of the problem, or when such systems contain tools that represent the problem inadequately, the end-users involved in collaborative and group decision processes are limited in their ability to estimate the risks and consequences of inappropriate management, policies, or planning strategies. Hence, the integration of spatial modeling and visualization approaches is crucial for generating new and intuitive ways of examining real-world problems.

Effective spatial decision support systems should have powerful and easy-to-use interfaces, interactive and recursive problem-solving capabilities, and analytical models with data for the exploration of solution spaces supporting multiple decision-making styles (Densham 1991). However, these characteristics are yet to be fully integrated into the systems. On the modeling front, the integration of land-use models into spatial decision support systems is still in its infancy (White et al. 2004). There is a need for enhanced visual modeling capabilities (Batty et al. 2006) and for improved, realistic, well calibrated, and validated simulation models. On the geovisualization front, more sophisticated visualization approaches capable of dealing with the spatial and temporal dimensions are progressing in the GIScience areas of geo-collaboration (MacEachren and Brewer 2004) and geo-visual analytics (Adrienko et al. 2007). Integrating the spatial modeling and visualization perspectives can provide new ways of effectively dealing with the complex nature of geographic problems.

This special issue of Cartography and Geographic Information Science(CaGIS) focuses on some of the work done to respond to these needs, drawing special attention to current research on integrating geospatial modeling and visualization so as to enrich and support the decision-making process. In the first paper, Jun Chen, Chaoying He, Jie Jiang, and Gang Han present a distributed method that extends speech act theory to the negotiation and reconciliation of inconsistent perspectives of different participants in a spatial decision environment. They implemented a Web prototype that permits visualization and analytical use of geospatial data and speech acts for conflict elimination in spatial decision making process applied to curbing the spread of infectious disease.

Mathieu Petit, Cyril Ray, and Christophe Claramunt outline in their paper a contextual modeling approach based on adaptive interaction in GIS which takes into consideration the relevance of geographical data, geographic context evolution, and levels of management for various user group profiles. The approach is applied to mobile and distributed GIS used in maritime navigation.

In the third paper, Shahram Yassemi and Suzana Dragićević extend a cellular automata model of forest fire propagation to a web-based spatial environment. The model augments the capacity of stand-alone dynamic models and provides a framework for real-time asynchronous decision-making process that can incorporate experts and stakeholders to intervene in disaster management situations.

Zeng Chang and Songnian Li describe the development of a three-dimensional web GIS collaborative environment for group decision-making in the fourth paper. Their prototype system permits shared 3D visualization, place-time interactions, and geospatial data.

In the final paper, Christian Stock, Ian D. Bishop, Alice N. O’Connor, Tao Chen, Christopher J. Pettit, and Jean-Philippe Aurambout present landscape planning tools using virtual reality and GIS technologies. The tools provide a collaborative multi-user decision making environment for real-time, three-dimensional exploration of spatial data and hypothetical scenarios of process models. Collectively, these five papers capture the mainstream of current spatial decision support systems research.

PAPERS

Reconciliation of Inconsistent Perspectives in Collaborative GIS

Jun Chen, Chaoying He, Jie Jiang, and Gang Han

Collaborative GIS provides a spatially referenced negotiation environment for decision makers to put forward their perspectives, discuss their differences, and, ultimately, make decisions. Recent research has focused on enabling the representation of, and selection from among, different opinions, while discussion among people has been ignored. This paper reports on a discussion process aimed at reconciling inconsistent perspectives in distributed workgroups. The Speech Act Theory (SAT) of Austin was extended to define both non-spatial and spatial speech acts in the context of a negotiation. A coordination process was modeled by these speech acts. Then, inconsistent perspectives were reconciled using detection of inconsistency, or initial integration of perspectives, or reconciliation of collaborators. The method we propose makes it possible to effectively describe the speech acts and use them to naturally represent the reconciliation process. A prototype system based on this approach was implemented in experiments. Their results demonstrate that a good abstraction of the negotiation process will facilitate the coordination of discussion among people and provide a criterion for system designers.

KEYWORDS: Collaborative GIS, inconsistent perspectives, speech-act theory (SAT), reconciliation process modeling

An Adaptive Interaction Architecture for Collaborative GIS

Mathieu Petit, Cyril Ray, and Christophe Claramunt

The research presented in this paper explores and models the interactions needed for the development of a collaborative and adaptive geographic information system (GIS). The proposed framework is based on a multidimensional contextual approach that differentiates between the user, the geographical, and the device contexts. The spatial distribution of the GIS functional components allows for the characterization of different geographical context configurations. These configurations act as a support for the derivation of user groups. The interfaces and functionalities offered by the adaptive GIS are modeled at the group level and derived from the interface usages and habits. The spatial behaviours that denote user experiences within a group are shared with other users within that group. Such an approach provides an adaptive and collaborative environment that favors exchanges and enriches the quality of services offered to the users acting in such a GIS environment. The framework was tested in the context of maritime navigation.

Web Cellular Automata: A Forest Fire Modeling Approach and Prototype Tool

S. Yassemi and S. Dragićević

The integration of geographic information systems (GIS) and spatio-temporal modeling procedures with Internet technology can significantly improve the decision-making process for environmental and disaster management. The objective of this study is to develop an approach to integrate a cellular automata (CA) forest fire behavior model with the world wide web. The developed CA model extends the capability of the static raster GIS by incorporating spatial dynamics into the forest fire phenomena. The developed CA model comprises topographic, forest fuel and weather variables as the key drivers of forest fires. The web-based modeling environment used ASP.NET as the server-side platform, and client-side programming with JavaScript extended the functionality of the web client. The web-based CA model and its consistent user-friendly interface will provide fire managers with a decision support and rapid disaster management tool with such advantages as access to real-time geospatial and environmental data, computer platform independence, and enhanced accessibility of spatial modeling tools.

KEYWORDS: Web modeling, cellular automata, Web GIS, forest fires, simulation methods, spatial decision support.

Architecture Design and Prototyping of a Web-based, Synchronous Collaborative 3D GIS

Zheng (Eric) Chang and Songnian Li

Collaborative GIS has emerged as an efficient, spatial decision-making tool, especially when 3D GIS models are integrated. While centralized architecture is still dominating the design and development of such tools and/or systems, alternative architecture, such as peer-to-peer (P2P), and hybrids have been given increasingly more attention in designing more scalable and efficient systems. This paper presents a conceptual hybrid system architecture for the development of integrated, synchronously collaborative environments with 3D GIS tools for group decision-making and 3D information sharing. In this paper, we discuss the major design issues related to such an architectural design and identify the spatial requirements of synchronous collaborative 3D GIS. A hybrid architectural model integrating centralized and replicated computing architecture is then designed to address the identified requirements. The proposed architecture was tested using data/message flow models developed to facilitate component-based collaborative 3D GIS systems. The results show that collaborative 3D GIS require collaboration computing different from that applied in generic GIS systems, and that a component-based development approach can lead to more light-weight systems.

KEYWORDS: 3D GIS, synchronous collaboration, distributed environment

SIEVE: Collaborative Decision-making in an Immersive Online Environment

Christian Stock, Ian D. Bishop, Alice N. O’Connor, Tao Chen, Christopher J. Pettit, and Jean-Philippe Aurambout

Over the recent years, spatial data have become more accessible to members of the public, and there is an increased awareness that spatial data are an essential ingredient in the development of governance policies. In parallel, computing devices that can render real-time 3D environments in nearly photo-realistic quality have become a common household item. Integrating spatial data and virtual environments opens the possibility of presenting spatial data in a highly visual way—the same way we experience our everyday world. We have developed a landscape planning tool called SIEVE (Spatial Information and Visualization Environment), which allows users to explore existing spatial data and hypothetical future scenarios in a real-time 3D environment, links to environmental process models outcomes, and also provides a collaborative decision-making environment. SIEVE has an automatic model-building component that allows users to select a region on a 2D map using a web portal and to download automatically generated 3D landscape environments. SIEVE not only models above-ground features but also incorporates underground features. This allows users to see the connection between below- and above-ground processes. Lastly, SIEVE incorporates a multi-user environment that allows users from different locations to gather in the virtual landscapes for exploring and decision-making purposes.

Books for Review

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