SLOSH (Hurricane Surge) mv_slosh.shp

Metadata also available as

Metadata:

Identification_Information:
Citation:
Citation_Information:
Originator: U.S. Army Corps of Engineers
Publication_Date: 10/30/02.
Title: SLOSH (Hurricane Surge) mv_slosh.shp
Geospatial_Data_Presentation_Form: vector digital data
Online_Linkage:
\\server\GIS_DATA\GIS_Files\Warehouse\Data_Files\Natural_Resources\FloodPlain\MEMA\mv_slosh.shp
Description:
Abstract:
Worst case Hurricane Surge Inundation areas for category 1 through 4 hurricanes striking the coast of Massachusetts or New Hampshire. Hurricane surge values were developed by the National Hurricane Center using the SLOSH (Sea Lake and Overland Surge from Hurricanes) Model. This Surge Inundation layer was created by the U.S. Army Corps of Engineers, New England District. Using ArcInfo's Grid extension, MassGIS 1:5,000 scale 3 meter land elevation data was subtracted from the worst-case hurricane surge values to determine which areas could be expected to be inundated.
Purpose:
This layer was developed to assist emergency management official in hurricane preparedness and operations.
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 10/30/02
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -70.839364
East_Bounding_Coordinate: -70.444958
North_Bounding_Coordinate: 41.484570
South_Bounding_Coordinate: 41.298707
Keywords:
Theme:
Theme_Keyword_Thesaurus: Surge
Theme_Keyword: Hurricane
Place:
Place_Keyword: Massachusetts
Place_Keyword: New Hampshire
Access_Constraints: None.
Use_Constraints:
This layer was developed to assist emergency management official in hurricane preparedness and operations.
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Matthew Walsh
Contact_Organization: U.S. Army Corps of Engineers, New England District
Contact_Position: Civil Engineer
Contact_Address:
Address_Type: mailing address
Address: 696 Virginia Road
City: Concord
State_or_Province: MA
Postal_Code: 01742
Country: U.S.
Contact_Voice_Telephone: 978-318-8647
Contact_Facsimile_Telephone: 978-318-8080
Contact_Electronic_Mail_Address: [email protected]
Native_Data_Set_Environment:
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.3.1.1850
Data_Quality_Information:
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Quantitative_Horizontal_Positional_Accuracy_Assessment:
Horizontal_Positional_Accuracy_Value: +/- 3 meters
Horizontal_Positional_Accuracy_Explanation:
Mass.GIS elevation data is 1:5,000 scale. The SLOSH model has been shown to be accurate within =/- 20%.
Vertical_Positional_Accuracy:
Quantitative_Vertical_Positional_Accuracy_Assessment:
Vertical_Positional_Accuracy_Value: +/- 1.5 meters
Vertical_Positional_Accuracy_Explanation:
Mass.GIS elevation data is 1:5,000 scale, suitable for 3 meter contours, with an accuracy of +/- 1.5 meters. The SLOSH model has been shown to be accurate within =/- 20%.
Lineage:
Process_Step:
Process_Description:
Obtained SLOSH (Sea, Lake and Overland Surge from Hurricanes) model output from the National Hurricane Center. The data was provided in ArcView shapefile format as two polygon shapefiles. One of the polygon shapefiles represented the Narragansett Bay / Buzzards Bay SLOSH Basin, and the other shapefile represented the Boston Bay SLOSH basin. Each polygon contained four attribues. The attributes represented the water surface elevation (in feet) that would occur from the worst-case hurricane surge within each polygon for hurricane categories 1 through 4. The shapefile was in a Geographic NAD 27 horizontal coordinate system.
Process_Step:
Process_Description:
Projected the SLOSH source polygon shapefile from Geographic NAD 27 to NAD_1983_StatePlane_Massachusetts_Mainland_FIPS_2001.
Process_Step:
Process_Description:
Use XTools to create a point shapfile of the centroids of the polygons.
Process_Step:
Process_Description:
Created four point shapefiles from the previous point shapefile, each representing the four permutations of Category 1 through 4 hurricane surge. Within each of the four shapefiles, deleted records that contained values of "99.9" for the represented permutation, which represented areas that were not flooded in the SLOSH model runs.
Process_Step:
Process_Description:
Interpolated each of the shapefiles to produce interpolated raster surfaces (ArcInfo Grids) representing the hurricane surge water elevation for each particular hurricane scenario. Used IDW interpolation, with the following parameters: power = 2, Search radius type: Variable, Number of points: 6. Used a cell size of 10 meters to facilitate interpolation, as smaller cell sizes proved to be too computationally intensive. This resulted in raster grids representing the four permutations of hurricane categories. This completed the preparation of the water surface grids. The next step was to prepare the land surface grids.
Process_Step:
Process_Description:
Downloaded land surface elevation data from MassGIS. Mass.GIS elevation data is 1:5,000 scale, suitable for 3 meter contours, with an accuracy of +/- 1.5 meters. The data was then used to create TINs (triangulated irregular networks) measured in feet and then converted into an ArcInfo Grid format.
Process_Step:
Process_Description:
The next step was to subtract the land surface grids from the water surface grids to create rasters depicting which areas would and would not be flooded (inundated) by worst-case hurricane surge for each of the two antecedent tide scenarios. See subsequent process steps.
Process_Step:
Process_Description:
Created inundation grids or lattices (called ilats here for "inundation lattices") by running the below AML (Arc Macro Language) program using ArcInfo GRID.
/* Run from Grid
setcell 3 setwindow maxof
ilat = con(c1 - c:\mahes0206\elevgrids\lat > 0, 1, ~ c2 - c:\mahes0206\elevgrids\lat > 0, 2, ~ c3 - c:\mahes0206\elevgrids\lat > 0, 3, ~ c4 - c:\mahes0206\elevgrids\at > 0, 4)
Process_Step:
Process_Description:
Ran the following aml program to set the nodata values of the raster = "10" prior to running the ArcInfo Grid "Fill" command.
/* Run from Grid
setcell 3 setwindow maxof
set10 = con(isnull(ilat), 10, ilat)
Process_Step:
Process_Description:
Converted each of the inundation grids to polygon shapefiles in preparation of clipping them to MassGISS TOWNSSURVEY_POLY polygon shapefile.
Process_Step:
Process_Description:
Selected polygons from the TOWNSSURVEY_POLY polygon shapefile that encompassed the identified coastal towns, and exported that subset to a new shapefile. Then dissolved the polygons to remove boundaries at town lines.
Process_Step:
Process_Description:
Clipped each of the inundation shapefiles to the subsetted, dissolved version of TOWNSSURVEY_POLY polygon shapefile.
Process_Step:
Process_Description:
Converted each of the cllipped polygon inundation shapefiles into rasters (grids).
Process_Step:
Process_Description:
Ran the following AML program to set the nodata values of the rasters (which after the clip are the values seaward of the coastline) = "0" prior to running the ArcInfo Grid "Fill" command.
/* Run from Grid
setcell 3 setwindow maxof
set0 = con(isnull(clip), 0, clip)
Process_Step:
Process_Description:
Ran the ArcInfo Grid "Fill" command to fill any "sinks" or depressions in the inundation grids. These would occur in areas that are low, but which have higher ground between their location and the coast which would prevent coastal surge from reaching the area. In previous process steps, the land areas were set to "10", and ocean and river areas were set to "0". In between, the inundation was coded as 1 thorugh 4 according to hurricane category. Therefore, the "Fill" command ensures that all flooding "flows" from high ground to low ground, or from 10 to 4, 3, 2, 1, and 0. The AML program is below.
/* Run from Grid
setcell 3 setwindow maxof
fill set0 fillexample sink
Process_Step:
Process_Description:
Ran the following AML program to set the areas that had been set to "0" or "10" prior to the filling operation back to "nodata".
/* Run from Grid
setcell 3 setwindow maxof
final = setnull(fillexample == 10 or fillexample == 0, fill)
Process_Step:
Process_Description:
Merged the inundation grids together to form one inundation grid that covered all of coastal Massachusetts. Used the ArcInfo Workstation Grid command "merge" to do this.
Process_Step:
Process_Description:
Converted the inundation grids to polygon shapefiles. This completed the preparation of the HurrSurge_CoastalMass shapefile.
Process_Step:
Process_Description: Metadata imported.
Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Vector
Point_and_Vector_Object_Information:
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: G-polygon
Point_and_Vector_Object_Count: 20866
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name: State Plane Coordinate System 1983
State_Plane_Coordinate_System:
SPCS_Zone_Identifier: 2001
Lambert_Conformal_Conic:
Standard_Parallel: 41.716667
Standard_Parallel: 42.683333
Longitude_of_Central_Meridian: -71.500000
Latitude_of_Projection_Origin: 41.000000
False_Easting: 200000.000000
False_Northing: 750000.000000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: coordinate pair
Coordinate_Representation:
Abscissa_Resolution: 0.000000
Ordinate_Resolution: 0.000000
Planar_Distance_Units: meters
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: Geodetic Reference System 80
Semi-major_Axis: 6378137.000000
Denominator_of_Flattening_Ratio: 298.257222
Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: mv_slosh
Attribute:
Attribute_Label: FID
Attribute_Definition: Internal feature number.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain:
Sequential unique whole numbers that are automatically generated.
Attribute:
Attribute_Label: Shape
Attribute_Definition: Feature geometry.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Coordinates defining the features.
Attribute:
Attribute_Label: ID
Attribute:
Attribute_Label: GRIDCODE
Distribution_Information:
Resource_Description: Downloadable Data
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Transfer_Size: 4.600
Metadata_Reference_Information:
Metadata_Date: 20090504
Metadata_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Matthew Walsh
Contact_Organization: U.S. Army Corps of Engineers
Contact_Position: Civil Engineer
Contact_Address:
Address_Type: mailing address
Address: 696 Virginia Road
City: Concord
State_or_Province: MA
Postal_Code: 01742
Country: U.S.
Contact_Voice_Telephone: 978-318-8647
Contact_Facsimile_Telephone: 978-318-8080
Contact_Electronic_Mail_Address: [email protected]
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
Metadata_Extensions:
Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile
Generated by mp version 2.9.6 on Mon May 04 19:22:13 2009