Free Geography Tools

Yesterday, I posted about ZeeMaps, an online application that comes close to GIS functionality. Today’s post deals with another online application that offers capabilities that you would normally find in a GIS stand-alone application, albeit in a somewhat simplified form. CleerImpact provides simple modeling of the results of a number of different disaster scenarios:

• Train Derailment
• Tanker Truck Accident
• Tire Fire (smoke)
• Oil Fire (smoke)
• Nuclear Steam Release
• Chemical Spill (ammonia, chlorine, propane)

CleerImpact uses a Google Maps interface to define the location of the accident, and plot the results. Enter the location using Google Maps, or enter a location in the search box and have it plotted. If the plotted location is not where you want it, you can drag the marker on the map to the right spot. CleerImpact also lets you use the scroll wheel on your mouse to zoom in and out, a nice touch that I wish other Google Maps sites would use as well. Once the position is selected, choose the scenario from the drop-down menu at left, and click on the Start button. CleerImpact will retrieve the current weather conditions at that location, run the scenario, and then plot the results in Google Maps. Here’s the screenshot of a simulated radioactive steam release from the Palo Verde nuclear power plant in Arizona (click on the image for a larger view):

It’s a calm day there today, so there’s no significant spread beyond the immediate vicinity of the plant; results would certainly be different on a windy day. The legend at upper right tells you the significance of the individual colors, and you can turn the plotted impact zones off and on with the check boxes. The plotted colors are actually partially transparent, but you have to zoom in a ways to see that. In the lower left of the screen, you’ll have the option of entering your location to see if you’re impacted by this event, and exporting the data plot to Google Earth.

The models used in CleerImpact are very simple, and have limitations:

• No terrain effects
• Ignore buildings, trees, or other obstacles
• Uses observed weather from the closest weather station, which may be several kilometers or more away.
• Use pre-set scenarios, so you can’t modify the amount of the spill or intensity of the fire
• Only simulate events using current weather data, can’t run simulations of past events

But Keigan Systems, the developer of the CleerImpact site, offers paid software and services that can take those factors into account.