TERN Geospatial Catalogue
Water count and water prevalence - NSW
This dataset indicates the presence and persistence of water across New South Wales between 1988 and 2012. Water is one of the world’s most important resources as it’s critical for human consumption, agriculture, the persistence of flora and fauna species and other ecosystem services. Information about the spatial distribution and prevalence of water is necessary for a range of business, modelling, monitoring, risk assessment, and conservation activities. For example, one of the necessary steps in the NSW State-wide Landcover and Trees Study (SLATS), which monitors vegetation change and is used in the production of vegetation maps, involves removing non-vegetative features such as water bodies through water masking.
Water count
The water count product is based on water index and water masks for NSW (Danaher & Collett 2006), and represents the proportion of observations with water present across the Landsat time series as a fraction of total number of possible observations in the 25yr period (1 Jan 1988 to 31 Dec 2012). The product has two bands where band 1 is the number of times water was present across the time series, and band 2 is the count of unobscured (i.e. non-null) input pixels, or number of total observations for that pixel. Cloud, cloud-shadow, steep slopes and topographic shadow can obscure the ability to count water presence.
Water Prevalence
The water prevalence product is extracted from the water count product and provides a measure of the relative persistence of water in the landscape (e.g. from always present to rarely and never present). There are 12 classes representing the percentage of time a pixel has had water present out of the total number of observations for that pixel (i.e Band 1/Band 2 of the water count product). Water prevalence mapping provides information for multiple, wide-reaching applications. For example, distance to locations of persistent water bodies can be modelled as a contributing indicator of potential biodiversity refugia.
Files align with Landsat paths and rows (see https://www.usgs.gov/core-science-systems/nli/landsat/landsat-tools), with files for water count denoted 'dd7' and water prevalence 'ddh'.
Simple
Identification info
- Date (Creation)
- 1988-11-19
- Date (Publication)
- 2021-09-22
- Date (Revision)
- 2014-07-14
- Edition
- 1.0
Identifier
Publisher
Author
- Website
- https://www.tern.org.au/
- Purpose
- The maps are intended for rural landscapes and are suited to many applications including: - property planning - local government planning - flood risk assessment and management - habitat identification and mapping - analyses of potential biodiversity refugia - analyses of landscape change and resilience
- Credit
- We at TERN acknowledge the Traditional Owners and Custodians throughout Australia, New Zealand and all nations. We honour their profound connections to land, water, biodiversity and culture and pay our respects to their Elders past, present and emerging.
- Credit
- This work was funded by Local Land Services and completed by the Joint Remote Sensing Research Program and the NSW Office of Environment and Heritage. Landsat data was sourced from the United States Geological Survey.
- Status
- Completed
Point of contact
- Topic category
-
- Environment
- Geoscientific information
- Imagery base maps earth cover
Extent
- Description
- New South Wales, Australia
))
Temporal extent
- Time period
- 1988-01-01 2012-01-01
Vertical element
- Minimum value
- 0.0
- Maximum value
- 0.0
- Reference system type
- Geodetic Geographic 3D
- Title
- Fisher, A., N. Flood, and T. Danaher. (2016) Comparing Landsat Water Index Methods for Automated Water Classification in Eastern Australia. Remote Sensing of Environment. doi:10.1016/j.rse.2015.12.055
- Website
-
Fisher, A., N. Flood, and T. Danaher. (2016) Comparing Landsat Water Index Methods for Automated Water Classification in Eastern Australia. Remote Sensing of Environment. doi:10.1016/j.rse.2015.12.055
Related documentation
- Title
- NSW OEH (2015) Water count and water prevalence fact sheet
- Website
-
NSW OEH (2015) Water count and water prevalence fact sheet
Related documentation
- GCMD Science Keywords
- ANZSRC Fields of Research
- TERN Platform Vocabulary
- TERN Instrument Vocabulary
- TERN Parameter Vocabulary
- GCMD Horizontal Resolution Ranges
- GCMD Temporal Resolution Ranges
Resource constraints
- Use limitation
- The Creative Commons Attribution 4.0 International (CC BY 4.0) license allows others to copy, distribute, display, and create derivative works provided that they credit the original source and any other nominated parties. Details are provided at https://creativecommons.org/licenses/by/4.0/
- File name
- 88x31.png
- File description
- CCBy Logo from creativecommons.org
- File type
- png
- Title
- Creative Commons Attribution 4.0 International Licence
- Alternate title
- CC-BY
- Edition
- 4.0
- Access constraints
- License
- Use constraints
- Other restrictions
- Other constraints
- These data can be freely downloaded and used subject to the CC BY licence. Attribution and citation is required. Please send citations of publications arising from work that use these data to tern@uq.edu.au .
- Other constraints
- Known Issues - Map accuracy - the water mask classified raining data with 1.4% misclassification. - Artificial striping in Landsat 7 imagery, associated with the edges of flight paths. - Ghosting - where a single date of poorly rectified Landsat images causes an offset in the water mask by some distance to the rest of the time series. This is particularly apparent for permanent water bodies such as wide river channels and large dams.
- Other constraints
- TERN services are provided on an “as-is” and “as available” basis. Users use any TERN services at their discretion and risk. They will be solely responsible for any damage or loss whatsoever that results from such use including use of any data obtained through TERN and any analysis performed using the TERN infrastructure. Web links to and from external, third party websites should not be construed as implying any relationships with and/or endorsement of the external site or its content by TERN.
Resource constraints
- Classification
- Unclassified
- Supplemental Information
- Files align with Landsat paths and rows (see https://www.usgs.gov/core-science-systems/nli/landsat/landsat-tools), with files for water count denoted 'dd7' and water prevalence 'ddh'.
Distribution Information
Distributor
Distributor
Distribution Information
Distributor
Distributor
- OnLine resource
- Water count and water prevalence
- OnLine resource
- Landsat Path Row KML files
Data quality info
- Hierarchy level
- Dataset
Report
Result
- Statement
- The following issues were identified: Map accuracy - the water mask classified training data with 1.4% misclassification. Artificial striping in Landsat 7 imagery, associated with the edges of flight paths. Ghosting - where a single date of poorly rectified Landsat images causes an offset in the water mask by some distance to the rest of the time series. This is particularly apparent for permanent water bodies such as wide river channels and large dams.
Resource lineage
- Hierarchy level
- Dataset
Process step
- Description
- Water index & water mask: The water index is developed by detecting water and non-water signatures from Landsat satellite imagery for a single date. The water mask is derived from the water index, based on research of an optimal threshold of water discrimination (Danaher & Collett 2006). Water presence/absence is assessed for each 30m Landsat pixel. This is the primary product used to develop the water count and water prevalence products, which are based on the Landsat time series (1 Jan 1988 to 31 Dec 2012).
Process step
- Description
- Water count: The water count product is calculated, per pixel, as the sum of number of observations with water present across the Landsat time series as a fraction of total number of possible observations in the 25 year period (1 Jan 1988 to 31 Dec 2012).
Process step
- Description
- Water prevalence: The water prevalence product is extracted from the water count product and classified by proportions of observations with water present.
Reference System Information
- Reference system identifier
- EPSG/EPSG:4326
- Reference system type
- Geodetic Geographic 2D
Metadata
- Metadata identifier
-
urn:uuid/4e391ec1-87a5-4bfb-9b51-997b87473494
- Title
- TERN GeoNetwork UUID
- Language
- English
- Character encoding
- UTF8
Point of contact
Type of resource
- Resource scope
- Dataset
- Metadata linkage
-
https://geonetwork.tern.org.au/geonetwork/srv/eng/catalog.search#/metadata/4e391ec1-87a5-4bfb-9b51-997b87473494
Point-of-truth metadata URL
- Date info (Creation)
- 1988-11-19T00:00:00
- Date info (Revision)
- 2016/06/20T00:00:00
Metadata standard
- Title
- ISO 19115-1:2014/AMD 1:2018 Geographic information - Metadata - Fundamentals
- Edition
- 1
Metadata standard
- Title
- ISO/TS 19115-3:2016
- Edition
- 1.0
Metadata standard
- Title
- ISO/TS 19157-2:2016
- Edition
- 1.0
- Title
- Terrestrial Ecosystem Research Network (TERN) Metadata Profile of ISO 19115-3:2016 and ISO 19157-2:2016
- Date (published)
- 2021
- Edition
- 1.0
Identifier
Overviews
Spatial extent
Provided by
