public safety in the wildland-urban interface · decision/lead time (ics) warning time...
TRANSCRIPT
Public Safety in the Wildland-Urban Interface
Thomas J. Cova Center for Natural & Technological Hazards (Cnth)
Professor, Department of Geography University of Utah, Salt Lake City
Living with Fire in California’s Coast Ranges
Sonoma State
May 8, 2018
October 20, 1995
V = population / # of exits
Mission Canyon, Santa Barbara
1938
Mission Canyon, Santa Barbara
6 homes 2 exits
420+ home 2 exits
1990
Leisure World Golf Course (1862 households, 2 exits)
748 households (1 exit?)
One-way-in One-way-out Communities
Rank Nodes FireHaz Housing Exits HUs to exits Lat Long State
1 57 0.75 806.4 1 806.4 33.167 -117.134 SoCal
2 59 0.70 803.6 1 803.6 33.192 -117.319 SoCal
3 64 0.90 776.7 1 776.7 34.152 -118.211 SoCal
4 79 0.95 755.9 1 755.9 39.627 -106.417 CO
5 51 0.84 748.3 1 748.3 39.619 -106.100 CO
6 75 0.88 630.7 1 630.7 39.593 -106.010 CO
7 47 0.81 597.1 1 597.1 39.474 -106.058 CO
8 66 0.86 571.7 1 571.7 32.941 -117.158 SoCal
9 13 0.74 560.2 1 560.2 34.169 -118.530 SoCal
10 44 0.83 552.7 1 552.7 33.150 -117.291 SoCal
124 as of Nov. 13 …
Evacuation Time Phases
Incident detection time
Decision/Lead time (ICs)
Warning time (notification)
Preparation time (households)
Network clearing time (traffic)
Evacuation Time
Problems can occur in any number of phases
T1 T2
Los Alamos Evacuation Plan: 2000 Cerro Grande Fire (approximately 2 to 2.5 hours)
Dirt road
Fire
1
1
1 3:00 pm
2
3:30
3
3
4:00
4
4 5:30
Varying intersection conflicts
a) no action
d) no conflicts
b) blocked entrances
c) induced merge
crossing conflict
merging conflict
upstream road block
traffic pylon
2012 Waldo Canyon Fire, CO
2000 Cerro Grande Fire warning time ~ 1 week
Evacuation warning?
Warning Triggers
Hazard
Trigger Point
Community
Evacuate!
Recreating the 2013 Yarnell Hill Fire, AZ
Lightning ignition: 5:38 pm, June 28th, 2013 8400 acres 129 buildings 19 firefighter fatalities, 23 civilian injuries
Yarnell Hill Fire
10:00 am,
Sunday, June 30
11:19 am Evacuation notice for Model
Creek and Double Bar A Ranch.
9:27 am
First pre-evacuation
notice issued.
1:00 pm
2:02 pm NWS issues first gusts and
thunderstorm alert.
2:26 pm Alert:
“Yarnell is on four-
hour stand-by.” 1:40 Fire fighters report:
“Pre-evacuation trigger point
is reached for Yarnell.”
3:00 pm
3:26 pm NWS issues second gusts and
thunderstorm alert (40+ mph, North).
3:33 pm “Mandatory
evacuation for Peeples
Valley.”
4:08 pm “Mandatory
evacuation for Peeples
Valley and Yarnell.”
4:00 pm
4:15 pm
4:28 pm “Shrine” trigger
point reached, fire
fighters pull back.
4:30 pm
Fire reaches
Glen Illah.
4:40 pm
4:50 pm
4:49 pm 911 caller, “All
of Glen Ilah is on fire!” Granite Mountain Hot
Shot deployment
and burnover.
5:00 pm
In-place Shelter
Barona Casino, SD, CA
May 6, 2018
A resilient fire-prone community …
Has a well-designed evacuation plan that considers
likely scenarios/contingencies (and conducts drills).
Has a reliable alert/warning system that’s tested.
Has viable protective back-up plans when lead
times are short (in-place shelter/refuge options).