Towards immersive virtual environments for GIS based hydrologic modeling

The tools of Geographic Information Systems have become increasingly valuable in hydrologic assessments and play an integral role in decision-making processes for flood prediction and mitigation. On the other hand, a quite distinct activity has been the development of GIS-based simulation modeling and visualization systems including realistic landscape visual simulations. Typically GIS, hydrologic simulation models, and virtual reality technology have been utilized as stand alone problem-solving domains. The increasing availability of high performance computation and visualization tools, offers new opportunities to combine sophisticated GIS modeling tools and emerging immersive visualization and decision support environments. This research describes the development of an interactive environment that utilizes the tools of virtual reality and GIS to enhance spatial hydrologic modeling. More specifically this research involves development and application of an interactive virtual modeling environment for spatially explicit hydrologic modeling in support of flood mitigation and flood management decision-making for the Squaw Creek watershed in central Iowa. The environment contains tools to manipulate and display geospatial data, spatial explicit output flow predicted by the Hydrological Engineering Center\u27s Hydrological Modeling System (HEC-HMS) and an immersive virtual environment that uses the Cave Automatic Virtual Environment (CAVE) to increase perception and realism. A component of the study was to develop tools to perform spatial hydrologic modeling in a microcomputer-based three-dimensional virtual environment using a head mounted haptic display. The unique combination of spatially explicit hydrologic models with geospatial and virtual reality visualization tools improves hydrologic analysis of what-if land-use and land management options and their hydrological impacts provides an opportunity for rapid assessment of hydrological conditions for improved collaborative environmental decision-making, and enhance the ability of resources planners to navigate and interact with the synthetic landscape environment

The collaborative risk assessment environment in disaster management

In the past century the occurrence of natural disasters and man-made disasters have steadily increased with a significant loss of life, damage caused to infrastructure and property, and destruction of the environment. There is much evidence that natural disasters are growing on a global level. Dealing with disasters demand the involvement of a range of agencies collaborating and making collaborative decision. This research has identified the need for a collaborative platform to bring together a variety of information to enable multi-agencies to prepare for disasters and to enhance the resilience of cities. Risk assessment is a crucial aspect within the activities of multi-agencies. Risk assessment enhances emergency planning which can then be tested by detailed appraisals and exercises. Whenever risk assessment is updated, plans are revised and additional tests are carried out. Risk assessment helps multi-agency planners decide what resource requirements they need and what multi-agency activities need to be planned collaboratively in order to prepare for disaster. The aim of this research is to investigate the nature of an interactive map that can enhance multi-agency team collaboration in the risk assessment process in disaster management.This research uses the six-step risk assessment process used in Australia and New Zealand which is widely recognized as being good practice. These steps are Contextualization, Hazard Review, Risk Analysis, Risk Evaluation, Risk Treatment and Monitoring and Reviewing (Standards Australia/Standards New Zealand Standard Committee, AS/NZS ISO 31000:2009).In this research, the characteristics of a suitable interactive map for risk assessment was defined in collaboration with the senior practitioners within a multi-agency team in the UK. Semi-structured interviews were conducted with the senior managers of Category 1 responders in The Greater Manchester Local Resilience Forum (GMLRF) to capture the requirements for a multi-agency collaboration platform. The outcome of these interviews were used to capture the characteristics and develop the a prototype of the interactive map that can support risk assessment. Once implemented, the validation of the interactive map prototype was conducted involving senior practitioners of stakeholders in the GMLRF development group. The experiment was held in the THINKpod in ThinkLab, at the University of Salford. A total of 23 senior practitioners took part in the evaluation experiment. After a demonstration of a scenario and using the interactive map, the participants evaluated the prototype as a group and then completed questionnaires thatxvfeatured range of open, closed and rating scale questions. These questionnaires were designed to evaluate the perceived effectiveness and impact of the interactive map on strengthening collaboration among the multi-agency teams during risk assessment. The outcome of the evaluation shows a good level of satisfaction among the practitioners. The overall result suggests that the professionals view the interactive map as a good platform to support collaboration multi-agency teams in risk assessment activity

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

Interoperability Of Gis: A Distributed Object Architecture Based On A Canonical And Functional Models

This paper presents an approach for allowing interoperability among heterogeneous geographic information systems (GIS). It combines techniques from traditional interoperable information systems, spatial data modeling, and distributed object systems. It uses two models, a canonical spatial data model and a functional operator model, for resolving heterogeneity among spatial models and for allowing homogeneous access to various GIS. The canonical data model is used to specify spatial data types while the functional operator model is used to describe system operations or methods, associated with the spatial data types. Finally, it defines a set of database services to allow users to build virtual geographic information systems from the existing systems. Keywords: interoperability, geographical information systems, distributed objects, distributed environments. 1 INTRODUCTION Interoperable information systems consist of geographically distributed information systems with different data ..