Remember the computer game Sims City? Unless you are a young person I bet you do and you spent a few hours on a computer building your own little city. Sims City would let us all become city planners and the mayor to build skyscrapers, office buildings and fast food restaurants in the middle of a residential development. There were no zoning codes, no health inspections or other safely regulations to follow. All we need to do was build the buildings, roads, utilities and the infrastructures as we saw fit and play the game. Of course the objective of the game was to know where, when and how to build those building and the infrastructures. A public pool next to a waste disposal site may cause a major typhoid outbreak or a luxury hotel overlooking a landfill may not be the best use of investment money and setting the tax rate higher may cause a hardship to the residents of your city if there are no businesses or places of employment for them.
So is your city build like Sims City being played by some video game player or does it have more forethought in the planning and being managed by a Geospatial system? The one nice feature of Sims City was it was 3D and allowed fly-overs and walk-thoughs, taking you from one view to the next in a matter of minutes. You could see into the office building models, watch traffic drive by and even change the exterior of an office by adding landscaping. If a shopping center did not look right in one area you could pick it up and move it around until it did fit.
Well now you can do the same with your city and GIS data. Digital Cities are the new GIS systems. Systems that are 3 dimensional, systems that allow planners and other city officials to move proposed buildings or developments around the city or in and out of industrial parks. For the last decade GIS have been used to analyze our cities to find the right location for schools, shopping centers and where traffic lights or fire hydrants where needed. Those analyzed results where only two dimensional and only shown possible sites to construct the new features, they failed to provide a good visual representation of the location. This is where the digital cities come into play, not only can you select a site to place a new building on but also visualize the buildings on the sites before approval is obtained. There is even more you can do depending on the level of detail (LOD) that the digital city uses and the LOD used in those building models. What effect will that new office building have on the surrounding landscape? Will the exterior finish reflect sun light and maybe more importance heat onto the flowering landscape along the street or what effect will it have on the surrounding building if the existing building depends on solar energy for some of it energy sources.
Architects and developers are become more environmental conscious today and designing their structures as building information models (BIM). They are not just 2D drawings any longer. They are models with information attached to them. Just as a GIS system has been providing data on a water system such as pipe diameter, material, and water pressure these building models have thickness of the walls, material used in the wall construction, insulation values, fire rating and even more data than we in GIS know what to do with at this time.
So how can this information be of use in a GIS environment? We take it beyond the typical GIS and use that information a step farther, in a digital city model. With the information available to all city planners, department managers will be able to make better decision thought out their everyday leadership duties. In the typical GIS system of today a fire department responding to a fire alarm to a burning building has locations to the nearest fire hydrants and even water pressure available as they arrive at the scene. With a digital city model they could also have information on what materials the building houses, a floor plan showing where the hazard materials are stored and what are in the surrounding area. How about when a disgusted employee walks into an office building taking hostages? With a digital city model the police department can identify safe zones in the buildings, knowing where the occupants may be safe.
In the years of the cold war we had civil defense shelters for people to go to if the city came under attack. We may not need to worry about that today but what about a natural disaster? Do the people today know what buildings will protect them from a tornado? With a model of the city it would be easy to locate basements in buildings or underground parking areas. With these models it would be easy to locate the entrance and exits to those shelters.
When a high pressure water main breaks it not only leaves some areas without fresh water but also floods other areas. Today’s GIS system can show what areas will be without fresh water when that water line breaks but with a digital model with a terrain you can also show what areas will be flooded and how quick the flood waters may reach certain areas. It can show what other utilities (gas lines or underground electrical lines) may also be affected by the erosion from the rushing water or how the storm water system will handle the quick flooding.
There is an advantage to a digital model over the standard GIS system. Not only as a public safely tool but it can also serve as one of the main tool for city planners and zoning. Creating that model requires an investment but the return of that investment will outweigh the cost and time quickly. Not only will it be a more powerful GIS system but also can be used to promote your city. Just think of how many You-Tube videos you can post show casing your city as your fly over in a digital format. So leave the Sims City to the gamers and go Digital City Model.