3D Visualization of the Lower Quinnipiac River                              
Redevelopment Corridor

by

Natalia Hoyos and Ned Kalapasev

Introduction

3D visualization techniques for the display of geographical data is a useful tool to help the viewer understand and interpret spatial relations of multidimensional on the surface, atmosphere and underground. This technique has been used extensively in studies relating to atmospheric pollution, landform analysis, urban planning, mineral deposits and groundwater. Modeling in 3D is still limited, mainly because of the large amount of data and calculations needed. In this study, we used 3D GIS for the visualization of information related to brownfield sites located along the lower Quinnipiac River, Connecticut.

3D visualization of the Lower Quinnipiac River Redevelopment Corridor (LQRRC) was done in ESRI's ArcView 3.1 utilizing the 3D Analyst 1.0 extension. This extension enables users to create, analyze, and display surface data in a 3D viewer. The data used in this project was compiled by EN 643 and includes elevation, hydrology, town boundaries, infrastructure (streets, highways, railroads) and brownfield locations (Figures 1 and 2). We also built detailed views for the brownfields located in the town of Hamden, with site data on buildings and parcels (Figures  3 ,  4 ,  5 , &  6 ). Finally, we created a hypothetical groundwater contaminant plume to show how 3D can be used to display such data (Figures 7 and 8 ).

Some observations that can be drawn from the general views (Figures 1 &  2 ) are:

• The area presents a flat topography ranging mainly between 0 and 90 meters. Maximum elevations of 240 m are found to the northwest.
• The brownfield sites are evenly divided among the three towns and are located near roads, railroads and the Quinnipiac River.

• The majority of sites have existing buildings, and around 50% are being used in some way.
• The use of aerial photos as a background makes the 3D view more real, although 3D display produces some distortion, reducing the level of detail (Figure 6 ).

Some problems that we found when working with the 3D ArcView extension were related with the computer capability of dealing with large amounts of calculations and data. In addition, the extension doesn’t still allow the user to modify the graphical user interface (GUI). For this reason, it was not possible to create hotlinks and dialogs within the 3D views.

Conclusion

We found that 3D visualization, as a way of displaying data, is useful in providing information on general aspects and spatial relation of landforms, hydrology, populated areas, infrastructure and for this case, brownfield sites. Its major advantage, is that it makes it easier to visualize how objects are related to one another in space, and it allows the enhancement of certain characteristics by either exaggeration (vertical exaggeration of relief, contaminant concentration) or extrusion (buildings). The hypothetical scenario is just one example on how this tool can be used to display other relevant information, as it is produced. We believe that this will be very useful in future stages of the project. Finally, we consider that improvements in hardware and software are still needed to fully take advantage of the capabilities of the 3D analyst.

Relevant Links and References

Bell, M., Dean, C. and Blake, M. 1998. Forecasting the pattern of suburban growth: decision-support in a GIS framework. Ninth Biennial Conference of the
    Australia Population Association. University of Queensland, Brisbane.  Web Site
EPA 1998. Brownfields showcase community, Stamford CT. Fact sheet EPA 500-f-98-266.
Fisher, T.R. 1993. Use of 3D Geographic Information Systems in Hazardous Waste Site Investigations. Pages 238-247 in Goodchild, M.F., Parks, B.O. &
    Steyaert, L.T. (eds). Environmental Modeling with GIS. Oxford University Press, New York, New York.
McLaren, R.A. and Kennie, T.J. 1989. Visualization of digital terrain models: techniques and applications. Pages 79-98 in Raper, J (ed). GIS Three dimensional
    applications in Geographic Information Systems. Taylor & Francis, Bristol, Pennsylvania.
Swanson, J. 1999. The three dimensional visualization and analysis of Geographic Data. Web Site