permaculture

[jedd <jedd@progsoc.org>]

 Forwarded article for anyone who has both mulch and a fire risk.

 -------------- Forwarded -------------------------------------------

International Journal of Wildland Fire 15(3) 427-431 

*Ignition of mulch and grasses by firebrands in wildland-urban
interface fires*

Samuel L. Manzello A , B , Thomas G. Cleary A , John R. Shields A and
Jiann C. Yang A 

A) Building and Fire Research Laboratory, National Institute of
Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899-8662,
USA. 

B) Corresponding author. Email: samuel.manzello@nist.gov 


Abstract 
Firebrands or embers are produced as trees and structures burn in
wildland-urban interface (WUI) fires. It is believed that firebrand
showers created in WUI fires may ignite vegetation and mulch located
near homes and structures. This, in turn, may lead to ignition of homes
and structures due to burning vegetation and mulch. Understanding the
ignition events that are due to firebrands is important to mitigate fire
spread in communities. To assess the ignition propensity of such
materials, simulated firebrands of uniform geometry, but in two
different sizes, were allowed to impinge on fuel beds of shredded
hardwood mulch, pine straw mulch, and cut grass. The moisture content of
these materials was varied. Firebrands were suspended and ignited within
the test cell of the Fire Emulator/Detector Evaluator (FE/DE) apparatus.
The FE/DE was used to investigate the influence of an air flow on the
ignition propensity of a fuel bed. Ignition regime maps were generated
for each material tested as a function of impacting firebrand size,
number of deposited firebrands, air flow, and material moisture
content.



http://www.publish.csiro.au/view/journals/dsp_journal_fulltext.cfm?nid=114&f=WF06031