I just finished my second experience doing GIS for burned area emergency response (BAER). The BAER team produces a 2500-8 burned area report, which has to be done in a short time frame after a wildfire is brought under control (usually two weeks or less). The report recommends erosion control measures to mitigate runoff from burned areas. A lot of remote sensing and GIS pieces have to come together quickly to meet the deadline.
The USDA Forest Service Remote Sensing Applications Center produces a Burned Area Reflectance Classification (BARC) for every major wildfire. For the Levan Fire, the post-fire Landsat 8 acquisition was a bust due to clouds but we got an excellent EO-1 image two days later. Then we added a few polygons from field observations using the ArcGIS “Update” tool.
The BARC map is just the start. We also have to map and measure the affected roads and trails, and all streams within the fire perimeter. Our hydrologist and soil scientist need statistical breakdowns of burn severity classes by soil type, veg type, and land ownership. They create micro-watershed boundaries for the fire area, and these have to be analyzed in GIS to get the acreage, min/max elevation (feet), stream channel length, and mean slope (%).
Our BAER team used the Erosion Risk Management Tool (ERMiT) model to generate predicted erosion with and without treatment. To provide inputs for the model, I had to break down vegetation polygons by burn severity and calculate the mean slope and slope length. This was difficult for the Levan Fire because of the diverse and fragmented pre-fire vegetation.
Long story, but I came out of this recent experience with the realization that I am still not well enough prepared to do GIS for BAER. I’d like to hear from more experienced folks about how they do it. Time-saving shortcuts are needed. There may be tools I don’t know about.