20260323 11590700 1.0 FALSE Hazard_Inputs 002 20260223 16003600 20260223 16003600 150000000 5000 dataset 20260223 File Geodatabase Table Esri ArcGIS 13.3.0.52636 Hazard_Inputs This table includes the inputs informing the Hazard Index, normalized between 0 and 1. <DIV STYLE="text-align:Left;"><DIV><DIV>FFRA_Grid: This is a foreign key that relates to the Unique_ID field in the FFRA_Grid table. Distance_to_Drainage: Represents proximity to streams or rivers, normalized between 0 and 1, where a value of 1 represents the highest distance to drainage within the study area. A lower normalized distance-to-drainage value indicates closer proximity to a channel and higher flood potential.Slope: Controls runoff velocity and flow direction and a strong predictor of flash flood intensity in steep basins, normalized between 0 and 1, where a value of 1 represents the highest slope within the study area. A higher (steeper) normalized slope value indicates higher flash flood potential.Flashiness: Represents the flashy nature of landscape, normalized between 0 and 1, where a value of 1 represents the highest flashiness index within the study area. A higher flashiness index indicates higher flashiness potential.Hand: Represents local hydraulic position relative to drainage network, normalized between 0 and 1, where a value of 1 represents the highest HAND within the study area. A lower normalized HAND value indicates higher flood potential.Drainage_Density: Represents the local concentration of stream channels per unit area, normalized between 0 and 1, where a value of 1 represents the highest drainage density within the study area. A higher normalized drainage density value indicates higher flashiness potential.Rainfall: Represents 100-yr, 24-hr precipitation depths, normalized between 0 and 1, where a value of 1 represents the highest precipitation depth within the study area. A higher normalized rainfall value indicates higher flash flood potential.Flow Accumulation: Identifies concentrated flow paths and potential channel initiation zones, normalized between 0 and 1, where a value of 1 represents the highest flow accumulation within the study area. A higher normalized flow accumulation value indicates higher flood potential.Plan Curvature: Represents flow convergence and divergence zones by computing curvature perpendicular to slope direction, normalized between 0 and 1, where a value of 1 represents the highest plan curvature within the study area. A lower normalized plan curvature value indicates higher flood potential.TWI: Identifies runoff concentration/saturation zones, normalized between 0 and 1, where a value of 1 represents the highest TWI within the study area. A higher normalized TWI value indicates higher flood potential.Curve_Number: Represents spatial runoff potential, normalized between 0 and 1, where a value of 1 represents the highest curve number within the study area. A higher normalized curve number value indicates higher flash flood potential.TPI: Distinguishes ridge/valley and channel confinement and helps locate flash-flood routing corridors, normalized between 0 and 1, where a value of 1 represents the highest TPI within the study area. A lower normalized TPI value indicates higher flood potential.Profile Curvature: Controls flow acceleration, erosion, and deposition potential by computing curvature along direction of maximum slope, normalized between 0 and 1, where a value of 1 represents the highest profile curvature within the study area. A lower normalized profile curvature value indicates higher flashiness potential.SPI: Indicates erosive energy and peak flow hazard, normalized between 0 and 1, where a value of 1 represents the highest SPI within the study area. A higher normalized SPI value indicates higher flashiness potential.</DIV></DIV></DIV> This data was generated by WERC, using the United States Geological Survey (USGS) LiDAR 30-meter Digital Elevation Model (DEM), USGS National Land Cover Dataset (NLCD) Land Use / Land Cover (LULC), National Oceanic and Atmospheric Administration (NOAA) Atlas 14 100-year, 24-hour Gridded Precipitation Dataset, and the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) Gridded Soil Survey Geographic (gSSURGO) database. Curve Number Distance to Drainage Drainage Density Exposure FFRA Flashiness Flow Accumulation Hazard Height Above Nearest Drainage (HAND) Plan Curvature Profile Curvature Rainfall Slope Stream Power Index (SPI) Topographic Position Index (TPI) Topographic Wetness Index (TWI) <DIV STYLE="text-align:Left;"><DIV><DIV>While the hazard dataset has comprehensive coverage for the 30-county area, the product is tailored specifically to target flash flood-prone areas along rivers, streams, channels, or other waterways that warrant sirens (and may not fully capture localized or pluvial flooding mechanisms).The FFRA is provided for the 30-county area at a spatial resolution of 1-kilometer by 1-kilometer for better computational efficiency as well as to align with input data with the coarsest resolution among those that were used in this study. In addition, the selection of the 1-kilometer by 1-kilometer pixel grid for processing FFRA can avoid confusion about the intent of the product – a finer resolution may give a false impression about the precision or intent of this study. This study is not intended to site sirens as part of outdoor warning siren systems but to identify flash flood-prone areas that warrant sirens. FFRA with a resolution of 1x1 kilometer can adequately serve as foundational information for identifying flash flood-prone areas that warrant sirens given the audible radius for outdoor warning sirens typically ranging from approximately 1 to 2 miles.</DIV></DIV></DIV> Hazard_Inputs Table 83551 OBJECTID OBJECTID OID 4 0 0 Internal feature number. Esri Sequential unique whole numbers that are automatically generated. FFRA_Grid FFRA_Grid String 100 0 0 Curve_Number Curve_Number Single 4 0 0 Distance_to_Drainage Distance_to_Drainage Single 4 0 0 Drainage_Density Drainage_Density Single 4 0 0 Flashiness Flashiness Single 4 0 0 Flow_Accumulation Flow_Accumulation Single 4 0 0 Hand Hand Single 4 0 0 Plan_Curvature Plan_Curvature Single 4 0 0 Profile_Curvature Profile_Curvature Single 4 0 0 Rainfall Rainfall Single 4 0 0 SPI SPI Single 4 0 0 TPI TPI Single 4 0 0 TWI TWI Single 4 0 0 Slope Slope Single 4 0 0