A coastal hazards data base for the US Gulf Coast

Abstract

This document describes the contents of a digital data base that may be used to identify coastlines along the US Gulf Coast at risk to sea-level rise. The data base integrates point, line, and polygon data for the US Gulf Coast into 0.25{degree} latitude by 0.25{degree} longitude grid cells and into 1:2,000,000 digitized line segments that can be used by raster or vector geographic information systems (GIS) as well as by non-GIS data base systems. Each coastal grid cell and line segment contains data on elevation, geology, geomorphology, sea-level trends, shoreline displacement (erosion/accretion), tidal ranges, and wave heights. To allow for the identification of coastlines at risk from sea-level rise, 7 of the 22 original data variables in this data base were classified by vulnerability and used to create 7 relative risk variables. These relative risk variables range in value from 1 to 5 and may be used to calculate a coastal vulnerability index for each grid cell and/or line segment. The data for these 29 variables (i.e., the 22 original variables and 7 risk variables) have been placed into the following data formats: (1) Gridded polygon data for the 22 original data variables. Data include elevation, geology, geomorphology, sea-level trends, shoreline displacement (erosion/accretion), tidal ranges, and wave heights. (2) Gridded polygon data for the seven classified risk variables. The risk variables are classified versions of: mean coastal elevation, geology, geomorphology, local subsidence trend, mean shoreline displacement, maximum tidal range, and maximum significant wave height. (3) 1:2,000,000 line segment data containing the 29 data variables (the 22 original data variables and the seven classified risk variables). (4) Supplemental point data for the stations used in calculating the sea-level trend and tidal range data sets. (5) Supplemental line segment data containing a 1:2,000,000 digitized coastline of the US Gulf Coast as defined by this document.