Solve Real-World Problems (Solutions from Synergis Tutorial)1 Dec, 2007 By: Steve Skarbowski
A real-world example of how AutoCAD Map 3D can help protect communities.
Imagine that there's a tank farm located in a highly populated area, and it includes 12 tanks of various liquids. A severe thunderstorm moves in, a lightning bolt strikes one of the tanks, and it catches on fire. The tank contains hazardous gasoline materials, which start leaking, and local officials order an evacuation. The smoke is very dense and is starting to affect a major highway. At this point, firefighters don't really know what chemicals they can use to extinguish the flames.
This is a real-world scenario that many of our first responders face in emergency situations.
Luckily, the owners of this tank farm facility use AutoCAD Map 3D. The ability to store and disseminate information quickly and accurately is crucial to the safety of citizens in the surrounding vicinity, and AutoCAD Map 3D can help.
Location of tanks.
Our area of interest has 12 tanks, a gas line with valves, an interstate highway and adjoining parcel information, and a photo of a tank. Note that photo can be added to AutoCAD Map 3D through a process called Hyperlinks, which can give a visual representation of the features. Hyperlinks can include PDFs, DWFs, or TIFF images.
All the above features have data associated with them. This data is stored in tables and contains attributes that are related to each data item. The tables can come from various sources, such as Oracle, SQL, DBF, and Access databases. The following is an example of the data table for the storage tanks. In the table, we can see the following information: tank identification number, type of material, and potential quantity (in gallons) of material stored within each tank.
The information provided can be invaluable for the emergency response personnel who respond to this incident. By knowing the potential quantity and contents of each tank, they can respond faster and be equipped with the correct type of chemical retardant to extinguish the fire.
An additional data table is available for the gas line and valves, and it can be useful for the gas company to locate the shut-off valve. The table can include information such as gas line size and type, along with valve information such as left- or right-turn valve type.
Table showing type and size of tanks.
In addition, a digital elevation model (DEM) can be used to generate contours and represent the topography of the site. Contours are equal lines of elevations. These contours can help hazardous waste teams determine the probable flow of the chemicals. By knowing the likely flow direction in advance, emergency crews can contain the flow of materials before it reaches any environmentally sensitive areas. The yellow path in the image below has been extracted from a DEM file to graphically show the potential flow of the chemicals. This information is useful for protecting the stream that is bordering the site.
Table showing type and size of tanks.
Let's take the scenario one step further.
The tank is leaking toxic fumes, and an evacuation is needed. AutoCAD Map 3D provides a tool called Buffer, which can calculate a distance from a point or lines to find information contained in this area. In this example, parcel owners and/or emergency response personnel can be notified quickly to evacuate, thus saving time and potentially lives. In this example, we construct a 1,000' buffer, represented by the circle, from the feature source, which is our red tank. The result shows which parcels must be notified.
Buffer showing affected area.
To make things a little more clear, we can query from a feature source and filter the data to show which parcels are affected by the emergency.
Feature Source Query Tools
AutoCAD Map 3D 2008 can perform a query based on different properties. In this example, let's use the location definition and a crossing polygon as the boundary to select the affected areas. This is known as a spatial filter.
Spatial query to show parcels affected.
The query generated a circular polygon and shaded only the parcels that fall within the buffer boundary. The ability to sort through large amounts of data quickly and accurately is essential to the response team's efforts.
The other feature that is contained within the buffer zone is a major highway. The buffer tool can also identify what portions of the road need to be closed. By having the ability to print out maps, police departments are able to see the best routes for detouring traffic around the emergency.
Buffer showing area affected.
From this query. we can get a tabular list for the parcels affected. The information stored in this table can include owner name, address, and parcel number.
Table showing affected addresses.
Join is a command used to link two tables with a common field. For example, we may have a parcel table that includes only owner name and parcel number. We may have another table that contains other information such as parcel number, owner name, and phone number. Because there's a common field between tables -- the parcel number -- we can join the tables to see the phone number and call the affected home owners.
Another useful tool is Autodesk Design Review. Design Review lets you take a snapshot (DWF). A DWF can contain areas of the map that must be changed. Crews can use design review to mark up maps in the field and then bring them back to the office and fix existing maps or create exhibits to explain the emergency and the effect it has.
Map showing spillage area of materials in the tank.
Helping to Avoid Major Disasters
In conclusion, we've seen some of the power of AutoCAD Map 3D and Design Review. By identifying the attributes associated with each feature and using spatial tools such as Buffer, Query, and Join, users can work to avoid a major disaster.
In this scenario, we had the ability to show the locations of our storage tanks and features affected. We were able to perform multiple queries about the data to help find solutions for the many possible scenarios of this type of emergency.
About the Author: Steve Skarbowski
In her easy-to-follow, friendly style, long-time Cadalyst contributing editor Lynn Allen guides you through a new feature or time-saving trick in every episode of her popular AutoCAD Video Tips. Subscribe to the free Cadalyst Video Picks newsletter, and we'll notify you every time a new video tip is published. All exclusively from Cadalyst!