Indicator 6.6.1: Change in the extent of water-related ecosystems over time
This indicator is meant to support the call in Target 6.6 to “protect and restore water-related ecosystems, including mountains, forests, wetlands, rivers, aquifers and lakes.” UN implementation of this indicator is focused primarily on using satellite imagery to identify: (a) changes in the spatial extent of lakes, rivers, reservoirs, inland wetlands, and mangroves; and (b) turbidity and eutrophication in large lakes. Results are presented in periodic reports and in online maps. However, the changes in water quantity are better captured by other data sources (especially the GRACE data discussed in Chapter 5), and there have been methodological issues with the water quality data. Systematic tracking of changes in inland and coastal wetlands (both destruction and restoration) would be a valuable service, but those data are not currently available through this indicator.