Predicting Areas of Debris Flows in Recently Burned Areas Using Precipitation Forecasts

Abstract

Debris flows are all too common in Southern California, especially in burned areas after a wildfire. This project predicts and informs of potential areas where a debris flow is likely to happen in the 10 counties of Southern California. Using digital elevation model data from the United States Geological Survey (USGS) and water catchment data from the United States Geological Survey’s Elevation Derivatives for National Applications (EDNA) database, the average slope was found in each water catchment, as debris flows follow the flow direction in the catchment. Using the National Interagency Fire Center’s fire perimeter data, recently burned areas were identified, as they are more susceptible to debris flows with the lack of vegetation holding the soil in place. Additionally, the National Weather Service’s National Digital Forecast Database (NDFD) was used to track predicted rainfall accumulation over 72 hours. This live data updates in 6-hour intervals, closely monitoring how much precipitation is expected. A model was created to analyze the data and make predictions on what is considered a no risk, low risk, medium risk, and high-risk area. An ArcGIS Dashboard was created to publicize the data, which provides information about what areas are prone to a debris flow, to help evacuate people and help utility crews with prevention and cleanup measures.