The surface area measurements reported here have been extracted from the Global Surface Water Explorer (GSWE). These figures may or may not match national figures on water body extent and have not been nationally validated. A permanent water surface is underwater throughout the year (whilst a seasonal water surface is underwater for less than 12 months of the year). This indicator only includes areas which have been identified as permanent. Additional details on the methodology is available here [hyperlink text in the word document] Metadata: https://environmentlive.unep.org/media/docs/projects/metadata_6_6_1.pdf, https://unstats.un.org/sdgs/metadata/files/Metadata-06-06-01a.pdf, https://unstats.un.org/sdgs/metadata/files/Metadata-06-06-01b.pdf