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.
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.
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
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'.
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).
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).
Water prevalence: The water prevalence product is extracted from the water count product and classified by proportions of observations with water present.