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Creating a Landscape Editor Rule
The landscape editor is a powerful yet easy-to-use tool for modifying a landscape. Fire Behavior Specialists can either add or import rules for the landscape file.
Note: Create the rules before creating the landscape file. If you add or edit rules after creating the landscape file, you will have to re-create the landscape file.
Adding rules allows you to edit the following attributes for the landscape fuels layers (canopy base height, canopy bulk density, canopy cover, fuel model or stand height) within the defined landscape extent:
- Globally change any of the landscape fuels layers to a new value or apply a conversion factor. EXAMPLE: Apply a conversion factor of 0.67 to the canopy cover layer.
- Globally change any of the landscape fuels layers to a new value or apply a conversion factor based on fuel model(s). EXAMPLE: Change the canopy base height to 0.5 for fuel model 165.
- Globally change any of the landscape fuels layers to a new value or apply a conversion factor based on rule conditions. EXAMPLE: Change the canopy cover to 15% if the aspect is between 135 and 225 degrees.
- Change any of the landscape fuels layers to a new value or apply a conversion factor based on rule conditions by fuel model(s). EXAMPLE: Change fuel model 102 to fuel model 101 if elevation is greater than 3300 meters.
- Change any landscape fuels layers based on an uploaded Landscape Mask. EXAMPLE: Change fuel models to 181 within the 2008ElkFire perimeter (loaded in as a landscape mask).
CAUTION: After creating a Landscape File that contains landscape edits, view the landscape to ensure that the edits you made in the Landscape Editor appear as you expected. A landscape critique will help with this task. Landscape editor rules are applied using Boolean logic and, if edits to your landscape do not appear as they should, read Landscape Editor Tips and make appropriate rule edits.
Landscape Editor Tips:
Consider the following when using the Landscape Editor in WFDSS to make landscape edits for fire behavior analysis.
- Once you import rules that have been used on another analysis, you can modify them as needed. However, rules using landscape masks are not imported, unless those masks are associated with the incident for which you are doing your current analysis.
- If a particular attribute (such as Fuel Model) is used in multiple rules, the order in which those rules appear makes a difference. The rules are executed in the order that they appear, from top to bottom. You can move them up, down, edit, or delete as needed.
- The rule highest on the list within each landscape fuels layer category takes precedence over any changes below it. Therefore, once an attribute (fuel model or canopy characteristic) is changed, it is not available for subsequent change in a rule later down on the list. For example, suppose you change FM 146 to 148 across the landscape, and further down the list, you apply a landscape mask and assign it FM 181. If the area contained by the landscape mask originally contained cells assigned FM 146, those cells have already been 'used' by the first rule, and they can't be changed to 181 in a subsequent rule. As a result, Your updated LCP will contain cells assigned FMs 148 and 181. This can easily be remedied by changing the order of the editor rules and applying the landscape mask fuel model change first.
- You can rearrange rules within a landscape fuels layer category, but you cannot rearrange the order of the catagories; rules within a category are executed independently of other categories, so rearranging the category order has no effect. For example, fuel model changes always appear at the top of the editor rule list.
- All changes made to an LCP (fuel model and canopy changes) query the original landscape to make the change. For example, if you change FM 164 to 145 in one rule and then create another rule to set the canopy cover for 145 to 0, the LCP editor only changes the canopy cover to 0 for the original 145, not for the 164 that was changed to 145 in an earlier rule. The system always queries the original landscape and applies edits to that landscape. Be sure the rules you add to the LCP editor are written to reflect changes to the original LCP and not subsequent fuel model adjustments. It might be handy to download the LCP critique before making any adjustments to landscapes, so that you can refer back to the critique when needing to make changes.
To change fuel models or canopy characteristics only outside of masked areas (in other words, retain values in masked areas and make adjustments outside of them), use the logic method that WFDSS applies to the landscape rules. To retain values inside of a mask while making changes outside of a mask, create two rules. The first rule retain the masked area's values and the second rule changes everything outside of the masked area. To retain canopy characteristic values inside of masked areas, multiply those by a value of 1 and then the subsequent rule is not applied to those areas because the first rule takes precedence.
To add a LCP editor rule:
Note: Landscape editor rules within each attribute category are applied from the top to the bottom of the list, so move the rules up or down the list as needed.
- From the Analysis List, select or create the analysis that you want to add rules for.
- Click View Information. The General Information page appears for the analysis.
- From the left menu, select Landscape Editor. The Landscape File Editor page appears.
- Click Add. The Add Landscape Editor Rule page appears.
- Select the attribute you want to change.
- Enter the new attribute value.
- Enter the rule conditions that apply to the attribute.
- Select the fuel model that applies to the attribute.
- If you want to limit the rule by a shape mask, add the mask that applies to the attribute. (The mask must exist in WFDSS for the incident before it will appear in the list.)
- Click Save. The Landscape Editor Rule page appears displaying the new rule in the list.
You can add or import more rules, or create your landscape file. Be sure to review your landscape rules before creating the landscape file.
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Last updated on 11/21/2017 2:22:52 PM.
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