Intertidal Extents Model Confidence Layer  

Authors / CoAuthors

Abstract

The Intertidal Extents Model (ITEM v1.0) product is a national scale gridded dataset characterising the spatial extents of the exposed intertidal zone, at intervals of the observed tidal range. The current version utilises all Landsat observations (5, 7, and 8) for Australian coastal regions (excluding off-shore Territories) between 1987 and 2015 (inclusive). The Intertidal Extents Model (ITEM v1.0) consists of three datasets derived from the Landsat NBAR data managed in the Australian Geoscience Data Cube (AGDC) for the period 1987 to 2015. The Confidence Layer (ITEM_CL_mosaic_1987_2015.tif) reflects the confidence level of the Relative Extents Model, based on the distribution of classification metrics within each of the 10% intervals of the tidal range. The layer should be used to filter region/pixels in the model where the derived spatial extents may be adversely affected by data and modelling errors. Note: The confidence layer should be utilised on a cell-by-cell basis. Standard deviation values within the confidence layer for a particular cell are not comparable to other cells within the model. Attributes: Single Band Integer Raster: 0 - Model is invalid. Indicates pixels where data quality and/or number of observations have resulted in no available observations in one or more of the percentile interval subsets. -32767 - No Data All other values - The pixel-based average of the NDWI standard deviations calculated independently for each 10% percentile interval of the observed tidal range (x 1000).

Product Type

dataset

eCat Id

100464

Contact for the resource

Digital Object Identifier

http://dx.doi.org/10.4225/25/575F47F34675D

Keywords

theme.ANZRC Fields of Research.rdf

• EARTH SCIENCES

GCMD Keywords

• Earth Science | Oceans | TidesEarth Science | Terrestrial HydrosphereEarth Science | Oceans

( Data centre )

• NCI

( Product )

• Intertidal Extents Model

• Published_External

Publication Date

2016-06-14T16:00:00

Creation Date

2016-06-02T14:00:00

Security Constraints

Australian Government Security ClassificationSystem    

Classification - unclassified

Legal Constraints

Creative Commons Attribution 4.0 International Licence    

Access - license

Use - license

Status

Purpose

The purpose of the ITEM v1.0 product is to assist in understanding the extent and elevation profile of the Australian intertidal zone. Examples of where this knowledge can contribute include environmental monitoring applications for migratory bird species, habitat mapping in coastal regions, hydrodynamic modelling, and geomorphology studies of features in the intertidal zone. Through attribution of the LOT and HOT values modelled for each cell, the extents model can be used to derive an elevation profile of the observed intertidal zone extent on a cell by cell basis. The method employed can be tailored based on user requirements. For example, by dividing the observed tidal range for a cell (HOT-LOT) into 10% interval values, contours can be assigned to the section of the Intertidal Extents Model contained in that cell. These can then be used as a standalone elevation data source, or interpolated to create a continuous intertidal digital elevation model for the cell. The ability to create an elevation model relative to MSL enables the data to be integrated as a complimentary data source, linking shallow water bathymetry and terrestrial elevation models.

Maintenance Information

asNeeded

Topic Category

geoscientificInformation

Series Information

Lineage

The Confidence Layer (ITEM_CL_mosaic_1987_2015.tif) reflects the confidence level of the Relative Extents Model, based on the distribution of classification metrics within each of the 10% intervals of the tidal range. The layer should be used to filter region/pixels in the model where the derived spatial extents may be adversely affected by data and modelling errors.

Parent Information

Extents

[-44, -10, 112, 154]

Reference System

Spatial Resolution

25m

Service Information

Associations

Downloads and Links

Download the data (tif)  

Intertidal Extents Model Collection  

Intertidal Extents Model Coastal Cells Shapefile  

Intertidal Extents Model Relative Extents Model  

Product Description (pdf)  

Source Information

Australian Data Cube ARG25 Surface Reflactance and Pixel Quality Assessment, in conjunction with the OTPS TPX08 Atlas Tidal Model and Normalised Difference Water index (NDWI). 50 112 154 -44 -10