Does Increased Santa Ana Wind Intensity Change Simulated Spatial Burn Probability In Southern California?
Abstract
In Southern California, seasonal downslope winds, called Santa Anas, are responsible for driving spread of some of the largest wildfires in the region. Santa Ana wildfires are of particular concern to the safety of people living in the highly populated wildland-urban interfaces of Southern California, because of their fast rate of spread. However, relatively little work has investigated the impact that these winds will have on spatial fire risk in the future.
Recently, we created a 120m x 120m resolution burn probability raster for Southern California using the stochastic large-fire simulation model FSim. FSim incorporates historical spatial ignition location, weather, topography, vegetation, and winds to conduct probabilistic fire spread modeling over 10,000 synthetic "fire years". Our burn probability raster is a spatial summary of fire risk across Southern California for the period 1992-2015, and incorporates wind speeds and directions that were recorded during this time period; for our simulations, historical daily winds were drawn from the Chilao Remote Access Weather Station (RAWS). But, how would our burn probability map change if the intensity of Santa Ana winds increased/decreased in the future? To begin to answer this question, we conduct a simple yet informative sensitivity experiment. First, we merge the historical record of daily winds at Chilao with a published reconstruction of days in which Santa Ana winds are known to have occurred during this period. Next, on each of these days, we: a) uniformly increase; and b) uniformly decrease the recorded wind speeds at Chilao. We use each altered wind stream as inputs to a series of FSim simulations to create burn probability rasters representing spatial burn patterns under scenarios of either a projected increase or decrease of Santa Ana intensity.- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMNH23C1042D
- Keywords:
-
- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 3322 Land/atmosphere interactions;
- ATMOSPHERIC PROCESSES;
- 0468 Natural hazards;
- BIOGEOSCIENCES;
- 0485 Science policy;
- BIOGEOSCIENCES;
- 1630 Impacts of global change;
- GLOBAL CHANGE;
- 4337 Remote sensing and disasters;
- NATURAL HAZARDS