Statewide Probabilistic Flood Hazard Maps for Idaho, USA: Ensemble Mean Water Depth and Flood Probability Datasets Derived from the Torrent Hydraulic Model

This dataset contains a statewide collection of probabilistic flood hazard products for Idaho, USA, generated using the 'Torrent' flood inundation model. The dataset consists of 48 flood scenarios representing combinations of four rainfall return periods (50-, 100-, 500-, and 1000-year), four rainfall durations (60 minutes, 6 hours, 12 hours, and 24 hours), and three rainfall uncertainty conditions (Mean, Upper and Lower 90% Confidence Bounds) derived from NOAA Atlas 14 precipitation frequency estimates. Each scenario was simulated using an ensemble of 100 model realizations, generated from combinations of hydraulic model parameters and stochastic realizations to quantify uncertainty in predicted flood inundation. For each scenario, two raster products are provided: Probability Map – the probability (0–1) that each grid cell is inundated based on the ensemble of model realizations using a threshold value of 0.5m. Ensemble Mean Water Depth Map – the ensemble-average flood water depth (m) computed across all realizations. All rasters have a resolution of 1 arc-second (approx. 30m) and are clipped to the Idaho state boundary and provided as Cloud Optimized GeoTIFF (COG) files with lossless LZW compression to facilitate efficient storage, cloud access, and visualization in web-based GIS applications. The datasets are referenced to WGS 84 (EPSG:4326) and maintain the original model grid resolution. These products are intended for flood hazard assessment, uncertainty analysis, hydraulic model evaluation, risk assessment, emergency management, infrastructure planning, and geospatial visualization.