GIS

Building a Better World in GeoWeb 2008, Part 1

24 Jul, 2008

Web-based GIS moves from descriptive to predictive modeling.


The geospatial community is hard at work building a new world. It's a world that's eerily familiar to us, because it's a digital replica of the one we live in.

Ron Lake, chairman and CEO of Galdos Systems, uses the term GeoWeb to express the ability to locally and globally integrate and share geospatial information via the Internet. In some ways, the GeoWeb is more manageable and a lot easier to navigate than the physical world. Linked to relational databases, user-created content, and search engines, the digital world lets you go beyond the facade of the superstructures and substructures around you. It gives you neighborhood crime statistics, property values, historical context, nearby bars and restaurants, and Wikipedia entries related to the features.

About 340 people who have a vested interest in the GeoWeb are currently in Vancouver, BC. They've come to the GeoWeb conference (July 21-25). In the next several days, they'll find better ways to merge the Web and the world captured in GIS. According to Lake, "The GeoWeb is not some application of GIS technology, nor is it InternetGIS — it is the Web."

Your World — Only Better
Alex Miller, founder and president of ESRI Canada, believes GeoWeb allows us to not only inventory the world as it currently is, but run experiments on how it might be improved. Citing A New Kind of Science, a book by scientist and business leader Stephan Wolfram, Miller said, "Cells are affected by cells around them. If you make a change to a cell, the perturbation travels to nearby cells. The real power of [GIS] comes in predictive modeling. What would happen if you were to build a freeway somewhere? We know freeways produce certain types of sprawls, developments, and population density. So you can predict the land use five to 10 years down the road in the area."

As an example of such applications, he points to CommunityViz, a community impact visualization tool with the most unlikely roots. In Weston, Vermont, a town with a population of 630, Lyman Orton and his three sons run the Vermont Country Store, a national mail order/Web business with two physical storefronts. Orton and his neighbor Noel Fritzinger founded the Orton Family Foundation as a resource for small cities and towns coping with the dramatic changes brought on the by building boom of the 80s in the region. The Foundation dedicated eight years to developing a 3D GIS visualization and decision-support tool, dubbed CommunityViz.

"What I like about the software," said Miller, "is that it takes all the data feeds from the sewer, water, and other municipal agencies, and brings it into a modeling environment. So if I put several houses in an area, I fill out a form that specifies 2.5 people per unit, there's a formula in the system that calculates how much additional water will be used, how much car and foot traffic it would create, and will show me in bar charts. So this allows you to run what-if scenarios." Comparing it to the popular city-simulation game, he described the program as "SimCity for real."

Equipped with Scenario 360 and SiteBuilder 3D, two ArcGIS extensions, the software allows you to create geographic scenarios, analyze their impacts, and view them in photorealistic 3D scenes. Now, the foundation has just launched the Big Box Evaluator, a Web-based program that will help small communities predict the socioeconomic impact of "big box" stores. Currently, Middlebury, Vermont, a college town of 8,500, is using it to evaluate and prepare for an anticipated Wal-Mart store proposal.

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CommunityViz allows small communities to visualize the impact of different land use scenarios (above). The analysis results can be output as a KML file, ready for viewing in Google Earth (below). (Click either image for a larger version)
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Building BIM Bridges
The GeoWeb is not built from scratch but rather assembled from existing data, some of which aren't authored in geospatial software but in design and drafting programs. In Miller's view, a peaceful coexistence between the two types of data — GIS and CAD — makes more sense than conversion from one to the other.

"The very names [of the two dominant CAD formats] DWG and DGN indicate they're drawings and designs," Miller observed. You're not talking about reality [as is] but about what is to be [a concept]. GIS is about recording reality. A lot of the constructs in CAD have been replicated in GIS, and vice versa, so you now have the ability to move data from CAD to GIS, but what you're talking about is giving a BIM [building information model] georeferences."

Galdos' Lake has frequently advocated the use of the Open Geospatial Consortium's (OGC) Web Feature Service (WFS) to link relational databases, such as those maintained in enterprise resource planning systems, to GIS applications. This makes it possible, for example, to connect specific zones in a map with the birthrates, mortality rates, and census reports relevant to them. The same procedures could be used to link CAD data to GIS.

"Basically, in GML (geography markup language), we already have something called the CityGML schema, a vocabulary to describe things in a city," he pointed out.

According to CityGML's home page, the schema is "an open data model and XML-based format for the storage and exchange of virtual 3D city models." With CityGML, you can automatically populate a map with building models stored in IFC format.

The CAD-BIM-GIS integration discussion from this year is but a prelude to what's coming in 2009. In the next 365 days, Lake and his colleagues at Galdos will be calling for academic papers on digital cityscapes and reviewing them. When GeoWeb returns in 2009, it will be GeoWeb Cityscapes.

For more on Web 2.0's impact on GIS and the culture of sharing, read Part 2 of this report.


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