Derived bathymetry of nearshore benthic habitats near Kaanapali, Maui, Hawaii

Identification_Information:

Citation:

Citation_Information:

Originator:

Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)

Publication_Date: 20111012
Title:

Derived bathymetry of nearshore benthic habitats near Kaanapali, Maui, Hawaii

Online_Linkage:

https://www.soest.hawaii.edu/pibhmc/cms/data-by-location/main-hawaiian-islands/maui/bathymetry/

Description:

Abstract:

Methods used were adapted from a "cookbook" of instructions developed by Kyle Hogref for using IKONOS imagery data to derive seafloor elevations in optically clear water. This dataset was derived from high-resolution (2 m) imagery from DigitalGlobe's WorldView-2 sensor of the Kaanapali area of Maui, Hawaii. Sensor bands 1,2 and 5 (coastal, blue and near IR respectively) were used to derive depth information. The method assumes uniform water clarity but deviations from that condition made extraction difficult in water greater than 30 m depth in the Kaanapali scene used. Results show that biotic material or sediment in the water column skewed results shallower if the material has a high albedo and deeper if the material has a low albedo. Nearshore areas were significantly less impacted in the Kaanapali area, due to the geomorphology of the area and the hi resolution and quality of the imagery, allowing visual descrimination of apparent sediment in the water column. For presentation purposes the map product shows an Inverse Distance Weighted interpolated bathymetry surface, restricted to data within 600 m of the shoreline.

Purpose:

DG WorldView-2 data are used as the base imagery to derived pseudobathymetry of the Kaanapali area of Maui. This area has both SHOALS and multi-beam acoustic derived bathymetry coverage and will provide an example case of the strengths and weaknesses of pseudobathymetry extraction from high resolution satellite imagery methods.

Supplemental_Information:

LiDAR bathymetry of Kaanapali, Maui from Scanning Hydrographic Airborne Operational LiDAR data from the United States Army Corps of Engineers Joint Airborne LiDAR Bathymertry Technical Center for Expertise. Multibeam sonar data from the Main Hawaiian Islands Bathymetry synthesis maintained by the Hawaii Mapping Research Group at the University of Hawaii, School of Ocean and Earth Science and Technology.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 20100406
Ending_Date: 20100406

Currentness_Reference: ground condition

Status:

Progress: Complete
Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -156.7760
East_Bounding_Coordinate: -156.6470
North_Bounding_Coordinate: 20.9839
South_Bounding_Coordinate: 20.8357

Keywords:

Theme:

Theme_Keyword_Thesaurus: NCEI Geoportal Filter
Theme_Keyword: CoRIS_Metadata

Theme:

Theme_Keyword_Thesaurus: CRCP Project
Theme_Keyword:

M218 Benthic Habitat Mapping and Characterization in the Pacific Islands Region

Theme_Keyword: 1217

Theme:

Theme_Keyword_Thesaurus: CoRIS Theme Thesaurus
Theme_Keyword:

EARTH SCIENCE > Oceans > Bathymetry/Seafloor Topography > Bathymetry

Theme:

Theme_Keyword_Thesaurus: None
Theme_Keyword: Bathymetry
Theme_Keyword: Multibeam sonar

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: elevation
Theme_Keyword: 006

Theme:

Theme_Keyword_Thesaurus: CoRIS Discovery Thesaurus
Theme_Keyword: Geographic Information > Bathymetry

Place:

Place_Keyword_Thesaurus: None
Place_Keyword: Maui
Place_Keyword: Main Hawaiian Islands
Place_Keyword: United States of America

Place:

Place_Keyword_Thesaurus: CoRIS Place Thesaurus
Place_Keyword:

OCEAN BASIN > Pacific Ocean > Central Pacific Ocean > Hawaiian Islands > Maui Island > Maui Island (20N156W0004)

Place_Keyword:

COUNTRY/TERRITORY > United States of America > Hawaii > Maui > Maui Island (20N156W0004)

Place:

Place_Keyword_Thesaurus: CoRIS Region
Place_Keyword: MHI

Access_Constraints: none
Use_Constraints:

These data are not to be used for navigation purposes. Please acknowledge the NOAA Pacific Islands Fisheries Science Center, and the Joint Institute for Marine and Atmospheric Research (JIMAR) and Hawaii Mapping Research Group (HMRG) at the University of Hawaii as the sources of this information.

Point_of_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:

Contact_Address:

Address_Type: mailing and physical address
Address: NOAA IRC
Address: NMFS/PIFSC/CRED
Address: 1845 WASP Blvd., Building 176
City: Honolulu
State_or_Province: HI
Postal_Code: 96818

Contact_Voice_Telephone: 808 725-5360
Contact_Facsimile_Telephone: 808 725-5429
Contact_Electronic_Mail_Address: nmfs.pic.credinfo@noaa.gov
Contact_Instructions: e-mail preferred

Browse_Graphic:

Browse_Graphic_File_Name:

https://www.soest.hawaii.edu/pibhmc/MHI_images/KaanapaliDerivedBathy_445.jpg

Browse_Graphic_File_Description: Layout of data on original satellite imagery
Browse_Graphic_File_Type: JPEG

Data_Set_Credit: PIBHMC, CRED, PIFSC, NOAA, JIMAR and HMRG
Security_Information:

Security_Classification_System: Not applicable
Security_Classification: Unclassified
Security_Handling_Description: Not applicable

Native_Data_Set_Environment:

netCDF file created using the Generic Mapping Tools (GMT) and ArcGIS ASCII file, both created in a LINUX environment

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report:

Data are collected for resource management and research purposes and are examined for internal consistency; however, no effort is made to compare these data to external references or to other published data.

Logical_Consistency_Report:

These data are believed to be logically consistent though no tests were performed

Completeness_Report: Complete
Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

Horizontal positioning system: GPS (SPS) Horizontal position accuracy: 25 m

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

1 m Raw sounding resolution: Variable

Lineage:

Process_Step:

Process_Description:

Multiple tools in ENVI 4.8 were used to complete the following processing steps: Data conversion from digital number to radiance, correction for atmosphere and water surface reflection, linearization of spectral decay as function of depth, masking of non-applicable values, and bathymetric derivation using variables from multiple linear regression analysis. Multiple tools in ArcGIS 10.0 were used for dataset integration and to extract values for the multiple linear regression analysis and subsequent error analyses. The statisitcs program Matlab was used for the multiple linear regression analysis to provide original variables for depth derivation. The multivariate slope intercept formula used to derive depth was D = a + (bi)(xi) + (bj)(xj) Where: D = depth a = intercept b = slope x = the linearized spectral value resulted in 7.8491 - 2.8696(b1) + 7.9593(b2) b1 is the output masked linearized pictral value of each pixel of Coastal band b2 is the output masked linearized pictral value of each pixel of Blue band More information on this integration process is provided in the product error analysis, availble from PIBHMC upon request. This mosaiced derived bathymetry product (JohDBall3) was then integrated with the multibeam sonar data, with sonar data prioritized over derived data, to create the final product (JohDB3MB). A detailed description of all processing steps is available at: ftp://ftp.soest.hawaii.edu/pibhmc/website/webdocs/documentation/Cookbook_042108.pdf An error analysis of each derived bathymetry grid used is available from PIBHMC upon request. To produce the interpolated surface shown in the map, the floating point grid was converted to a point shapefile in Arc GIS 9.3 using the 'float to raster' and 'raster to point' tools in the Arc Toolbox. A buffer of 600m from the shoreline was created and the derived bathymetry points were clipped to exclude data outside this buffer. This distance was chosen to exclude areas of deeper water that were erroneously returning shallow depth values, due to characteristics of the water column. An Inverse Distance Weighted interpolation was run using 3D Analyst, to produce an interpolated surface, with a grid cell size of 10 m, a variable search radius with a maximum distance of 60 m, and using the coastline as a barrier. All other settings used were default. The interpolated surface was clipped using the coastline and a small number of isolated cells were manually deleted.

Process_Date: 20111012

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:

Raster_Object_Type: Grid Cell
Row_Count: 5445
Column_Count: 5920
Vertical_Count: 1

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Grid_Coordinate_System:

Grid_Coordinate_System_Name: Universal Transverse Mercator
Universal_Transverse_Mercator:

UTM_Zone_Number: 4
Transverse_Mercator:

Scale_Factor_at_Central_Meridian: 0.9996
Longitude_of_Central_Meridian: -159
Latitude_of_Projection_Origin: 0.0
False_Easting: 500000
False_Northing: 0.0

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: Row and Column
Coordinate_Representation:

Abscissa_Resolution: 5
Ordinate_Resolution: 5

Planar_Distance_Units: meters

Geodetic_Model:

Horizontal_Datum_Name: D_WGS_1984
Ellipsoid_Name: WGS_1984
Semi-major_Axis: 6378137.000000
Denominator_of_Flattening_Ratio: 298.257224

Vertical_Coordinate_System_Definition:

Depth_System_Definition:

Depth_Datum_Name: mean lower low water
Depth_Resolution: 0.01
Depth_Distance_Units: meters
Depth_Encoding_Method: Attribute Values

Entity_and_Attribute_Information:

Overview_Description:

Entity_and_Attribute_Overview:

Depth values are real values based on the average of the soundings that fell within the extracted grid cells. The number of soundings per grid cell range from >1000 soundings in shallow depths to as few as 20 soundings in deeper areas. A total error budget for these data have not been developed. Therefore, the accuracy of depth measurements should be considered to be within 1 meter.

Entity_and_Attribute_Detail_Citation: none

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:

Contact_Address:

Address_Type: mailing and physical address
Address: NOAA IRC
Address: NMFS/PIFSC/CRED
Address: 1845 WASP Blvd., Building 176
City: Honolulu
State_or_Province: HI
Postal_Code: 96818

Contact_Voice_Telephone: 808 725-5360
Contact_Facsimile_Telephone: 808 725-5429
Contact_Electronic_Mail_Address: nmfs.pic.credinfo@noaa.gov
Contact_Instructions: e-mail preferred

Resource_Description: Downloadable Data
Distribution_Liability:

These data are not to be used for navigational purposes. NOAA makes no warranty regarding these data, expressed or implied, nor does the fact of distribution constitute such a warranty. NOAA cannot assume liability for any damages caused by any errors or omissions in these data, nor as a result of the failure of these data to function on a particular system.

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Format_Name: netCDF or Arc ASCII
Format_Information_Content:

These data can be downloaded as either a 2-D binary netCDF raster grid or an ArcGIS ASCII text file. The netCDF grid is the default grid file format used by GMT (Generic Mapping Tools), which created this file. More information can be located at http://www.soest.hawaii.edu/gmt/and https://www.unidata.ucar.edu/software/netcdf/. The Arc ASCII file, for use in ESRI's (http://www.esri.com) GIS software, can be converted to an Arc Raster Grid using ArcToolbox ASCII to Raster conversion tool.

Digital_Transfer_Option:

Online_Option:

Computer_Contact_Information:

Network_Address:

Network_Resource_Name:

ftp://ftp.soest.hawaii.edu/pibhmc/website/data/mhi/bathymetry/DD2_Depth2_filtermin4x4_10m.zip

Fees: None

Derived bathymetry of nearshore benthic habitats near Kaanapali, Maui, Hawaii

Metadata: