Fire Risks to Aquatic Habitats

Step Wise Guide

Pre Wildfire Planning

Where does the highest fire risk overlap with the highest fire severity, and where do they overlap the best aquatic habitats?

It is important to identify the locations across a watershed or landscape where the highest fire severity overlaps the highest quality and most sensitive aquatic habitat and species.

Step 1: Habitats may have already been mapped for three anadromous species (coho salmon, Chinook salmon, steelhead).

Go to NetMap Basic Tools > Maps > Aquatic Habitats > In drop down list, find coho, Chinook and steelhead. Values range from 0 to 1, poor to high quality habitat.

Step 2: To create the habitat values yourself, or to modify the habitat model (preference curves), Go To NetMap Aquatic Habitat Tools > Create Aquatic Habitats. Select either “Anadromous (Intrinsic Potential), Cutthroat trout (Bayesian) or Bull Trout (empirical). Follow Tech Help to create new habitat indices or to modify existing published models. Or create your own model.

OPTION 1 (easiest):

Step 3: Go To NetMap's Wildfire Cascade Tool. This tool allows display of predicted wildfire probability and severity (flame length) using data available from Western Wildland Environmental Threat Assessment Center (WWETAC). Post fire erosion prediction (surface erosion using the WEPP model) is also available in the tool based on results from Miller et al. (2011). An analyst can use this tool to quickly search for spatial overlaps of where predicted high fire probability and or severity overlaps various types of erosion potential and where those overlap with sensitive aquatic habitats.

OPTION 2: Wildfire - Erosion Tool

Step 1: Go to NetMap's Surface Erosion-Veg/Fire tool. The tool applies a spatially explicit version of the WEPP_Disturbed model for four difference scenarios: (1) no fire (surface erosion potential for unburned conditions using mapped vegetation classe), (2) Pre Wildfire (severity only) (surface erosion potential based on the most probable fire severity as predicted by WWETAC FireSim; FireSim predicted flame lengths (fire intensity) are grouped into three severity classes of High, Moderate and Low), (3) Pre Wildfire (burn probability combined with fire severity) (long term erosion regimes (frequency - magnitude distributions) that include both unburned and burned conditions (natural climate) over periods of a couple of hundred years (e.g., long term stochastic sediment budget) and (4) Post Fire ( post-fire erosion (severity) with a user-provided land cover layer that includes actual fire severity values (e.g., as contained within a Burned Area Reflectance Classification [BARC] map)).

For this application, a user would select either scenario #2 or #3; #2 may be most effective since it focuses solely on fire severity. Running the tool can be time consuming and thus the tool should be applied strategically to local areas. Running the tool at the scale of an entire NetMap dataset may take > 24hrs.

To search for the combination of highest fire severity, such as the highest 10% or highest 1% (etc) of fire probability, with the highest 10% or highest 1% (etc) predicted post fire surface erosion, Go To NetMap's Overlap Tool.