TITLE OF THE DATA BASE                                                         
                                                                               
A Coastal Hazards Data Base for the U.S. East Coast                            
                                                                               
                                                                               
CONTRIBUTORS                                                                   
                                                                               
Vivien M. Gornitz                                                              
National Aeronautics and Space Administration                                  
Goddard Institute for Space Studies                                            
2880 Broadway                                                                  
New York, NY 10025                                                             
                                                                               
Tammy W. White                                                                 
Oak Ridge National Laboratory                                                  
Environmental Sciences Division                                                
Oak Ridge, TN 37831-6335                                                       
                                                                               
                                                                               
SCOPE OF THE DATA                                                              
                                                                               
          The 29 data variables within A Coastal Hazards Data Base for         
the U.S. East Coast are designed for use by coastal planning,                  
research, and management agencies in combination with appropriate              
climatological data (e.g., Birdwell and Daniels, 1991). The data               
base may be used to identify coastal zones that are vulnerable to              
coastal erosion and inundation from sea level rise or storm surge.             
          This data base is comprised of the following data sets:              
elevation, bedrock geology, geomorphology, sea level trends,                   
horizontal shoreline movements (erosion/accretion), tidal ranges,              
and wave heights. For several of these data sets minimum, mean, and            
maximum data values are available. These data variables may be                 
divided into two basic classes, one that measures erosion potential            
and one that is related to inundation risk. The inundation risk of             
a given coastal grid cell may be estimated based on sea level                  
trends and elevations; whereas the erosion risk may be determined              
based on geology, geomorphology, shoreline displacement, tidal                 
ranges, and wave heights.                                                      
          Seven of the 29 data variables in this data base are                 
classified versions of other variables within this data base. The              
seven classified risk variables contain "risk values" of one to                
five for each coastal grid cell in the data base. These risk                   
variables may be used to calculate a Coastal Vulnerability Index               
(CVI) that may be used to identify areas on the East Coast that are            
vulnerable to sea level rise or coastal erosion.                               
                                                                               
                                                                               
DATA FORMATS                                                                   
                                                                               
          For ease of use, this data base has been divided into four           
data groups or coverages. The 22 original data variables have been             
provided in data group ECGRID (files ECGRID.E00 & ECGRID.ASC), the
7 relative risk variables have been provided in data group ECRISK
(files ECRISK.E00 & ECRISK.ASC), and the source information for the
tide and sea-level-trend data variables have been provided in the
supplemental data group ECPOINT (files ECPOINT.E00 & ECPOINT.ASC).             
In addition, an auxiliary file with a 1:2,000,000 digitized
coastline of the U.S. East Coast has been provided in ECOAST
(files ECOAST.E00 & ECOAST.ASC).                 
          For the data groups identified above, two different data             
formats were used. Each format provides the data registered to a               
0.25 degree latitude by 0.25 degree longitude grid [or in                
longitude/latitude coordinates in the case of ECPOINT (files
ECPOINT.E00 & ECPOINT.ASC) and ECOAST (files ECOAST.E00 & ECOAST.ASC).           
The first format is designed for use by the ARC/INFO Geographic               
Information System (GIS). This format stores the data as points,             
arcs, or polygons (based on the coverage in question).  The                
second format contains comparable data that has been converted            
into flat ASCII data files for use by raster GISs or non-GIS            
data base systems.                                                         
          For the data sets that were originally obtained as point data        
(i.e., sea level trends and tide ranges) the actual data variables,            
station names/numbers, record lengths, and latitude/longitude                  
locations have been provided in data group ECPOINT. Within data group          
ECPOINT, data are provided on the basis of the data point, thus allowing       
the precise location of each station used in calculating the data for the      
0.25 degree grid cells contained in ECGRID to be determined.  A         
description of the contents of each of the data groups and files                 
included with this data base follows:                                                        
                                                                               
                                                                               
(1)       ECGRID: Gridded polygon data for the 22 original data                
          variables. Data sets contained in this file include                  
          elevation, geology, geomorphology, sea level trend,                  
          shoreline displacement, tide range, and wave heights.                
                                                                               
(2)       ECPOINT: Point data for the stations used in calculating             
          the sea-level-trend and tide-range data sets. Data                   
          include station names/numbers, record length,                        
          latitude/longitude location, and mean and maximum data               
          values (when available).                                             
                                                                               
(3)       ECRISK: Gridded polygon data for the seven classified                
          risk variables. The risk variables are classified                    
          versions of the following original variables: mean                   
          coastal elevation, geology, geomorphology, local                     
          subsidence factor, mean shoreline displacement, mean                 
          tidal range, and the maximum significant wave height.                
                                                                               
(4)       ECOAST: 1:2,000,000 digitized coastline of the U.S. East             
          Coast. The coastline was extracted from a digitized map              
          of the United States compiled by the U.S. Geological                 
          Survey.                                                              
                                                                               
                                                                               
          To improve the portability of the information in the data            
files, FORTRAN 77 input/output routines (*.FOR) and SAS input/output          
routines (*.SAS) have been included with this data base for each of the         
flat ASCII data files. These input/output routines are intended to             
be used to read/write the data values contained in the flat ASCII              
data files [containing the gridded data base, the original point               
data (for sea level trends and tide range), and the digitized                  
coastline].  The FORTRAN 77 input/output routines were written to
run on a SUN SPARC workstation under UNIX using SUN FORTRAN
Version 1.3.  Slight modifications to the routines may be
necessary if running these codes on different platforms or under
different operating systems.
          The data groups in this data base are available as exported          
ARC/INFO coverages (Version 6.0.1). The export files must be read            
into an ARC/INFO GIS using the IMPORT command with the COVER                 
option after uploading the files onto a computer. These files are              
in a GEOGRAPHIC projection, which means the coverages are projected            
in a spherical reference grid using latitude and longitude                     
coordinates that are stored in decimal degrees (DD). The flat ASCII            
files contain an identical version of this data base. The gridding             
method used in this data base consists of 7,040 0.25 degree latitude             
by 0.25 degree (o) longitude grid cells. These cells cover the area              
defined by the following coordinates: 85W, 24N; 85W, 46N; 65W, 46N;             
and 65W, 24N. The origin of the grid is at 85W, 24N, and grid                  
identifiers increase from left to right, bottom to top. The data               
contained within each grid cell is valid for the entire grid cell.             
The data for a grid cell should not be construed as being                      
representative of a "point" in the cell -be it the lower-left                  
corner, upper-left corner, center, etc.                                        
          The flat ASCII versions of the files have been provided to           
allow use of these data by users who do not have access to                     
ARC/INFO. The format and contents of each of the flat ASCII files            
are described in the following section (the ARC/INFO coverages               
have the same variables and general format as described herein for             
the ASCII files).                                                              
          A line/arc version of the data in ECGRID and ECRISK is
also provided here as an ARC/INFO coverage (i.e., ECLINE.E00).
Coverage ECLINE contains 29 variables for each line segment in the
coverage; these line segments average 4.5 km length, and when
plotted, are equivalent to those found within the auxiliary file
ECOAST.                                                                               
                                                                               
DATA GROUP ECGRID:                                                             
                                                                               
          This data group contains gridded polygon data for the 22             
original data variables. These data variables are from the seven               
data sets and area as follows: minimum, mean, and maximum                      
elevation, and the number of 5' grid cells used in deriving the                
data values; geology; geomorphology; relative sea level trend,                 
long-term geologic-trend, corrected sea level trend, local                     
subsidence trend, and the years of record of the gauge stations                
used in calculating these values; mean, minimum, and maximum                   
shoreline displacement, and the number of 3', 7.5', or 15' grid                
cells used in deriving the data values; mean tide level, mean and              
maximum tidal range, and the number of tidal stations used in                  
calculating these values; maximum significant wave height and the              
20 year mean wave height and its standard deviation.                           
          The names of the ARC/INFO coverage and flat ASCII file in          
which these data variables reside are ECGRID.E00 and ECGRID.ASC,                
respectively. The file ECGRID.ASC is formatted as follows:             
                                                                               
                                                                               
 10       READ (5,100,END=999) ID, WHAVG, WHMAX, WHSD, ERAVG,                  
    1     ERMAX, ERMIN, ERNUM, ELAVG, ELMAX, ELMIN, ELNUM                      
          READ (5,110) GM, GL, TRMAX, TRAVG, TRLVL, TRNUM,                     
    1     SLR, SLG, SLC, SLS, SLYR                                             
                                                                               
 100      FORMAT(I5,6F8.2,I4,3F8.2,I4)                                         
 110      FORMAT(2I5,3F8.2,I4,4F8.2,I4)                                        
                                                                               
                                                                               
                                                                               
The variables in data group ECGRID (file ECGRID.ASC) are shown in  
Table 9 and are listed as they appear in the file.                                             
                                                                               
                                                                               
Table 9.           Variable formats for ECGRID.ASC.                   
                                                                               
Variable    Column     Variable            Variable                            
name     start   end    type             description                           
------------------------------------------------------------------------------ 
                                                                               
ID        1       5    Integer        System variable - grid cell identifier   
                                                                               
WHAVG     6      13    Real           Data variable - 20-year mean wave height 
                                      experienced within each 0.25o grid cell; 
                                      values in meters                         
                                                                               
WHMAX    14      21    Real           Data variable - maximum significant wave 
                                      height for each 0.25o grid cell; values  
                                      in meters                                
                                                                               
WHSD     22     29     Real           Data variable - standard deviation of    
                                      the 20-year mean wave height experienced 
                                      within each 0.25o grid cell; values in   
                                      meters                                   
                                                                               
ERAVG    30     37     Real           Data variable - mean long-term erosion   
                                      trend for given 0.25o grid cell; values  
                                      in meters                                
                                                                               
ERMAX    38     45     Real           Data variable - maximum long-term        
                                      erosion trend for a given 0.25o grid     
                                      grid; values in meters                   
                                                                               
ERMIN    46     53     Real           Data variable - minimum long-term erosion
                                      trend for a given 0.25o grid cell; values
                                      in meters                                
                                                                               
ERNUM    54     57     Integer        Data variable - number of 3', 7.5', or   
                                      15' grid cells used in calculating ERAVG,
                                      ERMIN, and ERMAX for a given 0.25o       
                                      grid cell                                
                                                                               
ELAVG    58     65     Real           Data variable - mean elevation of all    
                                      nonnegative 5' by 5' grid cells within a 
                                      given 0.25o grid cell; values in meters  
                                                                               
ELMAX    66     73     Real           Data variable - maximum elevation of all 
                                      nonnegative 5' by 5' grid cells within a 
                                      given 0.25o grid cell; values in meters  
                                                                               
ELMIN    74     81     Real           Data variable - minimum elevation of all 
                                      nonnegative 5' by 5' grid cells within a 
                                      given 0.25o grid cell; values in meters  
                                                                               
ELNUM    82     85     Integer        Data variable - number of 5' by 5' grid  
                                      cells used in calculating ELAVG, ELMIN,  
                                      and ELMAX for a given 0.25o grid cell    
                                                                               
--------------- SECOND LINE READS AS FOLLOWS -----------------                 
                                                                               
GM        1      5     Integer        Data variable - ordinal value indicative 
                                      of the type and susceptibility of the    
                                      landforms within a given 0.25o grid cell 
                                      to inundation and erosion                
                                                                               
GL        6     10     Integer        Data variable - ordinal value indicative 
                                      of the type and resistance of the rocks  
                                      within a given 0.25o grid cell to erosion
                                                                               
TRMAX    11     18     Real           Data variable - maximum tide range       
                                      measured for all gauge stations that     
                                      occurred within a given 0.25o grid cell  
                                      in 1988 (this value may be the "spring"  
                                      or "diurnal" tide range, depending on    
                                      geographic location); values in meters   
                                                                               
TRAVG    19     26     Real           Data variable - average of the mean tide 
                                      range for all the gauge stations that    
                                      occur within a given 0.25o grid cell     
                                      (mean tide range is the difference in    
                                      height between mean high water and mean  
                                      low water in 1988); values in meters     
                                                                               
TRLVL    27     34     Real           Data variable - the average of the mean  
                                      tide levels of all the gauge stations    
                                      that occur within a given 0.25o grid cell
                                      (mean tide level is a plane midway       
                                      between mean low water and mean high     
                                      water in 1988). Values were reckoned from
                                      chart datums (i.e., Gulf Coast Mean Low  
                                      Water Datum was used for the Florida     
                                      Keys; the Atlantic Coast Mean Low Water  
                                      Datum was used for the rest of the East  
                                      Coast)                                   
                                                                               
TRNUM    35     38     Integer        Data variable - number of tide gauge     
                                      stations used in calculating TRAVG,      
                                      TRMAX, and TRLVL for a given 0.25o       
                                      grid cell                                
                                                                               
SLR      39     46     Real           Data variable - relative sea level trend 
                                      within a given 0.25o grid cell; values in
                                      mm/year                                  
                                                                               
SLG      47     54     Real           Data variable - long-term geologic-trend 
                                      derived from 14C data for each 0.25o grid
                                      cell; values in mm/year                  
                                                                               
SLC      55     62     Real           Data variable - corrected sea level      
                                      trend. Tide-gauge data (i.e., SLR)       
                                      corrected for geologic trends (i.e.,     
                                      SLG) for each 0.25o grid cell            
                                                                               
SLS      63     70     Real           Data variable - the local subsidence     
                                      trend. Tide-gauge data (i.e., SLR)       
                                      corrected for the regional eustatic rate 
                                      of sea level rise (i.e., 1.25 mm/year)   
                                                                               
SLYR     71     74     Integer        Data variable - years of record used in  
                                      estimating the sea level trend for each  
                                      0.25o grid cell                          
------------------------------------------------------------------------------ 
                                                                               
                                                                               
Within ECGRID missing data values are indicated as follows:                    
                                                                               
                                                                               
9999.99 -  A grid cell with real data values that is missing data for a given  
data variable.                                                                 
                                                                               
9999 -  A grid cell with integer data values that is missing data for a given  
data variable.                                                                 
                                                                               
                                                                               
          A value of 0.0 is a valid value for all variables. For the elevation 
variables 0.0 m indicates that land occurs within the given grid cell, but the 
maximum elevation of this land is < 1.0 m. If the data variables in a given    
data set, such as elevation, contain data and the "number" variable is set to  
zero (i.e., ELNUM, ERNUM, TRNUM, or SLYR), then the data variables for the     
given 0.25o grid cell have been estimated on the basis of the methods          
discussed in Part 1 of this document.                                          
                                                                               
                                                                               
DATA GROUP ECPOINT:                                                            
                                                                               
          This data group contains the point data for the stations used in     
calculating the relative sea level trend, long-term geologic-trend, corrected  
sea level trend, local subsidence factor, mean tide range, maximum tide range, 
and mean tide level variables contained within data group ECGRID. Data include 
station names, station number, record length, latitude/longitude location, and 
data variable values.                                                          
          The names of the ARC/INFO coverage and flat ASCII file are         
ECPOINT.E00 and ECPOINT.ASC, respectively. A summary of the format used 
for file ECPOINT.ASC follows:                                                
                                                                               
                                                                               
 10       READ (5,100,END=999) ID, SLLONG, SLLAT, SLR, SLG,                    
    1     SLC, SLS, SLYR, SLNAME                                               
          READ (5,110) TRLONG, TRLAT, TRAVG, TRMAX, TRLVL,                     
    1     TRID, TRNAME                                                         
                                                                               
 100      FORMAT(I5,6F8.2,I4,A38)                                              
 110      FORMAT(5F8.2,I5,A45)                                                 
                                                                               
                                                                               
The variables listed in Table 10 are listed as they appear in data group       
ECPOINT (file ECPOINT.ASC).                                                              
                                                                               
                                                                               
Table 10.          Variable formats for ECPOINT.ASC.                  
                                                                               
Variable    Column     Variable            Variable                            
name     start  end     type             description                           
------------------------------------------------------------------------------ 
                                                                               
ID        1      5     Integer        System variable - Point identification   
                                      number                                   
                                                                               
SLLONG    6     13     Real           Data variable - longitude of the tide-   
                                      gauge station used in determining the    
                                      sea level trends                         
                                                                               
SLLAT    14     21     Real           Data variable - latitude of the tide-    
                                      gauge station used in determining the    
                                      sea level trends                         
                                                                               
SLR      22     29     Real           Data variable - relative sea level trend 
                                      measured for each tide-gauge station;    
                                      values are expressed in mm/year          
                                                                               
SLG      30     37     Real           Data variable - long-term geologic-trend 
                                      derived from C14 data; values are        
                                      expressed in mm/year                     
                                                                               
SLC      38     45     Real           Data variable - corrected sea level      
                                      trend. Tide-gauge data (i.e., SLR)       
                                      corrected for long-term geologic-trends  
                                      (i.e., SLG); values are expressed in     
                                      mm/year                                  
                                                                               
SLS      46     53     Real           Data variable - local subsidence trend.  
                                      Relative sea level trend corrected for   
                                      the regional eustatic rate of sea level  
                                      rise (i.e., 1.25 mm/year)                
                                                                               
SLYR     54     57     Integer        Data variable - years of record of the   
                                      tide-gauge station used in determining   
                                      the sea level trends                     
                                                                               
SLNAME   58     95     Char           Data variable - name of the tide gauge   
                                      used for determining the sea level trends
                                                                               
----------------- SECOND LINE READS AS FOLLOWS --------------------            
                                                                               
TRLONG    1      8     Real           Data variable - longitude of a tide-gauge
                                      station used for determining the tide    
                                      range variables                          
                                                                               
TRLAT     9     16     Real           Data variable - latitude of a tide-gauge 
                                      station used for determining the tide    
                                      range variables                          
                                                                               
TRAVG    17     24     Real           Data variable - difference between mean  
                                      high water and mean low water for 1988;  
                                      values in meters                         
                                                                               
TRMAX    25     32     Real           Data variable - maximum tide range,      
                                      maximum measured range for the gauge     
                                      station in 1988 (this value may be the   
                                      "spring" or "diurnal" tide range,        
                                      depending on geographic location);       
                                      values in meters                         
                                                                               
TRLVL    33     40     Real           Data variable - mean tide level, a plane 
                                      midway between mean low water and mean   
                                      high water in 1988. Values are reckoned  
                                      from chart datums (i.e., Gulf Coast Mean 
                                      Low Water Datum is used for the Florida  
                                      Keys; the Atlantic Coast Mean Low Water  
                                      Datum is used for the rest of the East   
                                      Coast)                                   
                                                                               
TRID     41     45     Integer        Data variable - station number (used in  
                                      the  988 Tide Tables) of a tide-gauge    
                                      station                                  
                                                                               
TRNAME   46     90     Char           Data variable - name of a tide-gauge     
                                      station (from the 1988 Tide Tables)      
------------------------------------------------------------------------------ 
                                                                               
                                                                               
Within this data file, missing data values are indicated with one of the       
following values:                                                              
                                                                               
                                                                               
0.0 or 0 -  A tide range or sea-level station that has not been assigned       
data for the variable in question.                                             
                                                                               
In this data group the sea level variables and tide range variables are        
mutually exclusive (i.e., if tide-range data are present, then the sea-level   
data are missing or vice versa).                                               
                                                                               
                                                                               
DATA GROUP ECRISK:                                                             
                                                                               
          This data group contains gridded polygon data for the seven          
classified risk variables. The risk variables are classified versions of the   
following original variables: mean coastal elevation, geology, geomorphology,  
local subsidence trend, mean shoreline displacement, mean tidal range, and     
maximum significant wave height.                                               
          The names of the ARC/INFO coverage and flat ASCII file are         
ECRISK.E00 and ECRISK.ASC, respectively. A summary of the format used  
in file ECRISK.ASC follows:                                                
                                                                               
                                                                               
10   READ(5,100,END=999) ID,                                                   
   1   ERR, LSR, WHR, ELR, GMR, GLR, TRR                                       
                                                                               
100  FORMAT(I5,7I4)                                                            
                                                                               
                                                                               
The variables in data group ECRISK, listed in Table 11, are shown as they      
appear in file ECRISK.ASC.                                                             
                                                                               
                                                                               
Table 11.          Variable formats for ECRISK.ASC.                  
                                                                               
Variable    Column     Variable            Variable                            
name     start  end     type             description                           
------------------------------------------------------------------------------ 
                                                                               
ID        1      5     Integer        System variable - grid cell identifier   
                                                                               
ERR       6      9     Integer        Data variable - classified version of    
                                      the mean erosion/accretion variable      
                                      (i.e., ERAVG)                            
                                                                               
LSR      10     13     Integer        Data variable - classified version of    
                                      the local subsidence trend variable      
                                      (i.e., SLS)                              
                                                                               
WHR      14     17     Integer        Data variable - classified version of    
                                      the maximum significant wave-height      
                                      variable (i.e., WHMAX)                   
                                                                               
ELR      18     21     Integer        Data variable - classified version of    
                                      the mean elevation variable              
                                      (i.e., ELAVG)                            
                                                                               
GMR      22     25     Integer        Data variable - classified version of    
                                      the geomorphology variable (i.e., GM)    
                                                                               
GLR      26     29     Integer        Data variable - classified version of    
                                      the geology variable (i.e., GL)          
                                                                               
TRR      30     33     Integer        Data variable - classified version of    
                                      the mean tide range variable             
                                      (i.e., TRAVG)                            
------------------------------------------------------------------------------ 
                                                                               
                                                                               
          Values of Zero are used in risk variables to identify grid cells     
that are missing data for a given data variable. If several "no data" values   
occur within the same grid cell, then any calculated coastal vulnerability     
index that uses these relative risk factors may not accurately represent       
the risk of the given coastal area to sea level rise or coastal erosion        
(unless some type of corrective action is taken). Grid cells that are not in   
the coastal zone, or are totally ocean bound, have values of zero for all      
seven derived risk variables.                                                  
                                                                               
                                                                               
                                                                               
AUXILIARY DATA GROUP, ECOAST:                                                  
                                                                               
          Auxiliary data group ECOAST (files ECOAST.E00 & ECOAST.ASC) 
contains a 1:2,000,000 digitized coastline of the U.S. East Coast. Data 
in this coverage were extracted from a digitized map of the United States       
(originally compiled by the U.S. Geological Survey).  This coastline may    
be overlaid onto any of the three data groups previously discussed to    
provide locational information when plotting any or all of the data
variables.                                     
          Unlike the other data groups within this data base, this coverage    
contains line segments (or arcs) that describe the U.S. East Coast. The        
coastline provided has no attribute values associated with the line segments.  
However, such overlay commands as UNION, INTERSECT, and IDENTITY in ARC/INFO 
(or other GISs) may be used to transfer the gridded data values to the coastal 
segments, thus simplifying the interpretation of any derived indices.          
          The name of the ARC/INFO coverage where the coastline resides is   
ECOAST.E00, and the flat ASCII data file with this same information is in 
ECOAST.ASC. Since this file is line based, the data values in ECOAST.ASC  
contain the line segment name, and a listing of the points that describe
each line, for all 934 line segments that define the East Coast.      
          The flat ASCII version of this file contains a listing of the line   
segments (or arcs) that describe the coast. An example of the format for this  
file is shown in Table 12.                                                     
                                                                               
                                                                               
Table 12.          Sample of the vector format used for ECOAST.ASC.  
                                                                               
                                                                               
Name, Number of points                                                         
------------------------------------------------------------------------------ 
                                                                               
"1", -5                      -Vector 1 uses 5 points to describe the line      
-71.0812,45.1245             -Start at 71.08oW Longitude, 45.30oN Latitude     
-70.6414,45.4167                                                               
-70.9824,45.5545                                                               
-71.0035,45.6234                                                               
-71.0334,45.7834             -End of arc                                       
"2", -13                     -Vector 2 uses 13 points to describe the line     
-71.0334,45.7834             -Start of next line                               
-71.2267,45.7734                                                               
-71.2946,45.7948                                                               
...                          -Continued                                        
------------------------------------------------------------------------------ 
                                                                               
                                                                               
ARC/INFO is a registered trademark (TM) of the Environmental Systems Institute 
         (ESRI), Inc., Redlands, CA 92372.                                     
SAS is a registered trademark of the SAS Institute, Inc., Cary, NC 27511-8000. 
                                                                               
                                                                               
END OF FILE