This dataset was generated using a modified version of the freely available Tropical Wetland mapping tool (TropWet, Hardy et al., 2020)) to calculate annual estimates of wetland extent. Data is provided in Byte GeoTiff format, dimensions 13,513 by 20,203, pixel resolution 30m, Coordinate Reference System EPSG:4326 - WGS84.
TropWet was developed for the geospatial cloud-based platform Google Earth Engine (GEE) enabling wetland maps to be produced over large areas through linear spectral unmixing (LSU) of Landsat imagery composites. In this instance, composites were generated over the Sudd each year between 1984-2022 for the months October-December, this representing the short rainy season during which the flood inundation extent is at its annual maximum.
LSU is used to derive per-pixel fractional cover of water, vegetation and bare soil. This fractional image is subsequently used in combination with band indices and terrain metrics within a ruleset to extract the following thematic classes: open water, inundated vegetation, wet soil, aquatic vegetation, as well as other background 'dry' classes. Below is a list of these classes alongside their raster value:
1: Inundated Vegetation
2: Wet soil
3: Dry vegetation
4: Open water
5: Dense vegetation
6: Bare soil
7: Aquatic vegetation
File naming convention.
mm_to_mm is the start and and end month
yyyy_to_yyyy is the start and end year (note that these will be same as these are annual outputs.
Note that some years are missing due to insufficient cloud-free imagery.