Shapefile of Areal Reduction Factor (ARF) regions for the state of Florida (ARF_regions.shp)

The South Florida Water Management District (SFWMD) and the U.S. Geological Survey have developed projected future change factors for precipitation depth-duration-frequency (DDF) curves at 174 NOAA Atlas 14 stations in central and south Florida. The change factors were computed as the ratio of projected future to historical extreme precipitation depths fitted to extreme precipitation data from various downscaled climate datasets using a constrained maximum likelihood (CML) approach. The change factors correspond to the period 2050-2089 (centered in the year 2070) as compared to the 1966-2005 historical period. An areal reduction factor (ARF) is computed to convert rainfall statistics of a point, such as at a weather station, to an area, such as a watershed or model grid cell. Regions considered for the development of change factors as part of this study study are taken from NOAA National Center for Environmental Information (NCEI) U.S. Climate Divisions for the state of Florida with some modifications in south Florida. Geospatial data provided in an ArcGIS shapefile are described herein. Areal reduction factors (ARF) and their standard deviation have been calculated for each region. For each model grid cell closest to each NOAA Atlas 14 station, return levels for extreme precipitation depth are adjusted from the area-scale to the station-scale by dividing by the areal reduction factor (ARF) for the ARF region where the station is located. See Areal_reduction_factors.xlsx and Table 1 of Datasets_station_information.xlsx for the ARF data by ARF region, event duration, and model grid-cell area.

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  "010:12"
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  "geospatial"
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