Gis Tool For Post Fire Hydrology Data

In the past several years, very large wildfires have become increasingly common. These wildfires may result in short-term impairments (1 – 5 years) to watersheds which can create dramatic increased threats from post-fire flooding and debris flows. Because of this, rapid assessments are needed to accurately identify potential threats to life and/or property. Post-fire watershed modeling is a key element in these emergency assessments by providing estimated increase in runoff and data for flood inundation boundaries. Curve Number (CN) based models are frequently used for post-fire hydrology. However, these CN models rely on a significant amount of input data that is processed from GIS. The individual geoprocessing steps can take several hours to develop the required model input data. The USDA Natural Resources Conservation Service in Washington State has developed a GIS tool, utilizing ArcGIS Pro, that automates these geoprocessing steps. This tool includes several of the required input datasets and automates almost all the geoprocessing steps while reducing this portion of the process from several hours to a few minutes. The output is provided in both tabular (Excel spreadsheet) and spatial feature (Esri shapefile) products for use with CN based hydrologic models.