Posts tagged plume
Depiction & DepictionPrep both make use of Depiction’s simulation technology, letting you do rapid, basic simulations of various scenarios. The two programs do have some differences–DepictionPrep only includes disaster simulation elements, and the variables for many of those elements have been simplified. Both of them, though, provide the ability to quickly consider “what if” scenarios in your own neighborhood–or pretty much anywhere else.
Let’s go through the elements available. Several of these elements make use of elevation data, whether brought in directly from Depiction’s Quickstart sources, or loaded from other sources. The higher resolution the elevation data is, the more precise these simulations will be.
Flood: The ‘classic’ Depiction simulation element, the flood very simply calculates what the water level would look like if it were set to a certain height above the ground level at a particular point. This works basically the same way in both Depiction and DepictionPrep.
Runoff: This does a basic ‘path of least resistance’ simulation of water flowing downhill, and works best in sloped areas–if you’re simulating a flood in an area like this, the runoff tool is likely to provide better results than the flood simulation itself. The full version of Depiction provides several variables that can be tweaked to customize the simulation result. The flood also disables people, buildings and elements that it comes into contact with.
Antenna and Line of Sight: Both of these elements, only included in the full version of Depiction, use a line-of-sight simulation behavior, determining what areas can be seen from a certain point, based on the elevation data present. The elements use the same behavior, but have different default variables–height, field of view, direction, ‘horizontal sampling’ (which determines the precision of the simulation) and maximum distance–set to approximate different things. The antenna element also has additional fields that, while they don’t affect the simulation, are of interest to anyone dealing with antennas, such as frequency, power, etc.
Other simulation elements make use of the road network data obtained from OpenStreetMap.
Route – road network (called simply Route in DepictionPrep): This is a basic, ’shortest distance’ route to which you can add waypoints, which also provides turn-by-turn directions if the street names are listed in OpenStreetMap. Additional route types are available in the new Logistics Add-on. Where the road network simulations really shine, though, is in the way they work if the roads do not.
Road barrier and Water over roadway: These elements both disable any road network they touch, causing routes to recalculate and find the next shortest path between waypoints. You can change both the shape and size of these elements to set any region you want as off-limits. This is an enormously useful tool for determining evacuation routes, or just general routing that avoids a certain area.
Explosion: This element does the same basic thing–set a blast radius, and the explosion disables the road network in the area–but in addition, the explosion also disables various other elements unfortunate to be caught in it.
Fire perimeter: This freeform polygon basically enables you to create your own shape that disables elements within it. In DepictionPrep, it also disables road networks as explosions and road barriers do–in the full version, this ability is easily added from the interactions menu.
Plume: Finally, this element does a very basic simulation of a chemical plume, using variables like amount, wind speed, wind direction and amount of time. This generic plume element isn’t nearly so accurate as something like ALOHA modelling, but for the purpose of quick simulation or scenario building for family preparedness, the plume element is a great option.
For more on simulation elements watch this Depiction 101 video.
The Depiction platform was created with the intention of allowing domain experts to integrate simulation models into custom elements to enable access of state-of-the-art simulations to the everyday user. The models in our initial retail version – such as flooding, runoff, plume distribution, evacuation routing, and signal propagation – demonstrate the power of simulations in visualizing ‘what if’ scenarios in the geographic domain.
The integration of an industry-standard simulation models, we believe, will enhance the usefulness of our modest tool. To that end, we have been eyeing programs such as ALOHA. An industry standard for modeling dispersion of hazardous chemicals, the ALOHA program was developed jointly by the National Oceanic and Atmospheric Administration (NOAA) and the Environmental Protection Agency (EPA). Available freely, this program has over 50,000 users in government and industry, and the accompanying CAMEO suite of software has had over 250,000 downloads since 2001.
A growing number of Depiction users have been requesting integration of ALOHA plume outputs with Depiction. We listened and now are working toward that… More >