Saturday, September 26, 2015

Notes on Wenatchee Fire

I had some field work in central Washington and got a bit of a glimpse of some of the burned areas from this summer's wildfires.
 
View of Wenatchee from East Wenatchee
Burned area was the Sleep Hollow Fire

At the edge of the city numerous homes were burned. The homes destroyed were in an urban setting adjacent to scrub steppe and grassland. Certainly causes one to rethink the hazard the low growing grasses in eastern Washington pose.

 



1991 aerial showing orchards and new homes on the west edge of Wenatchee

Same view from May 2015 with red circles around destroyed homes
Note that four homes well away from the edge of the city

The ground to the west of Wenatchee is steep and rugged, but there are roads and trails. However, despite the access and the fact the fire was burning downhill, this fire was very fast and due to high heat and wind.

Flying embers ignited fires over one mile from the edge of the city.

Red circle marks where buildings burned

Given the speed and intensity of the fire, one positive take away is that no one was killed. In that regard, emergency responders in central Washington have done an amazing job.

The fire that burned into Wenatchee and a similar fire that burned into Pateros might require some rethinking about fire hazard along the edge of urban communities. It is clear that controlling range fires when wind and heat combine is practically impossible.

Much attention and money has been placed on forest health and management in regards to wildfire. But rangeland and grassland management is clearly an issue. The really big acreage and fast moving fires in central Washington have very often involved a rangeland component and Wenatchee and Pateros are cautionary lessons.  
 

1 comment:

Geoffrey Middaugh said...

What your pictures show is the extent of the urban growth into the wildland urban interface (WUI), and the significant vegetative change resulting from historic management (e.g., overgrazing by cows and wildlife). In this case its the increase of annual grasses, which accelerates the fire cycle from what used to be 15-25 years down to 2-5 years, or so. Simplistically, twenty foot flame lengths in grass are just as damaging as twenty foot flames in trees. The management approach to this complexity at the federal and state levels is summarized in the Cohesive Strategy. The science and the strategies are available, but our governmental institutions are not yet there. See: http://www.forestsandrangelands.gov/strategy/