The importance of water-related ecosystems is specifically reflected in the water goal (SDG 6) and the terrestrial biodiversity goal (SDG 15). Target 6.6 aims “to protect and restore water-related ecosystems, including mountains, forests, wetlands, rivers, aquifers and lakes,” emphasizing their crucial role in water cycle functions and watershed management.
SDG 6.6 monitors changes in the spatial extent of waterrelated ecosystems. Given wetland losses and associated biodiversity declines, many countries respond with natural wetland protection and management programmes and environmental flow requirements (e.g. Mexico’s water reserves; South African National Water Act 1998 [Government of South Africa 1998]). River and wetland restoration and construction efforts are proceeding, including constructed wetlands for storm water treatment in Australia, recapturing floodplain areas in The Netherlands, and reconnecting wetlands and lakes to the main stem of the Yangtze River in China. Improved Earth observation data, combined with a classification methodology, enable countries to gain accurate pictures of their water-related ecosystems. However, there is a pressing need to extend on-the-ground monitoring of water cycle components and harmonize observations.
The Ramsar Convention on Wetlands (1971) is a multinational environmental agreement, devoted specifically to the conservation and wise use of wetlands. Each signatory country must designate and protect one or more “Wetlands of International Importance” (known as ‘Ramsar sites’). As Contracting Parties to the Convention, 170 countries had designated 2,326 Ramsar sites by early 2018. The total wetland area protected by the Ramsar designation has increased from 81 million ha to almost 250 million ha since 2000 (Figure 9.24). New Ramsar sites designated in recent years tend to follow hydrological boundaries, to protect whole catchments and river basins (Ramsar 2018).