SDG Indicator 6.6.1: Change in the extent of water-related ecosystems over time
1. Key features and metadata (a and b)
Definition: This indicator tracks changes over time in water-related ecosystems.
| Sub-indicator | Disaggregated by |
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EN_LKW_QLTRB Lake water quality turbidity (%) |
Deviation level (extreme, high, medium, low) |
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EN_LKW_QLTRST Lake water quality trophic state (%) |
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EN_WBE_NDQTGRW Nationally derived quantity of groundwater (millions of cubic metres per annum) |
No current data disaggregation available.
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EN_WBE_NDQTRVR Nationally derived quantity of rivers (million of cubic metres per annum) |
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EN_WBE_HMWTL Extent of human made wetlands (square kilometres) |
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EN_WBE_INWTL Extent of inland wetlands (square kilometres) |
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EN_LKRV_PWAN Lakes and rivers permanent water area (square kilometres) |
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EN_LKRV_PWAP Lakes and rivers permanent water area (% of total land area) |
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EN_LKRV_SWAN Lakes and rivers seasonal water area (square kilometres) |
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EN_LKRV_SWAP Lakes and rivers seasonal water area (% of total land area) |
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EN_LKRV_PWAC Lakes and rivers permanent water area change (%) |
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EN_LKRV_SWAC Lakes and rivers seasonal water area change (%) |
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EN_RSRV_MNWAN Reservoir minimum water area (square kilometres) |
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EN_RSRV_MNWAP Reservoir minimum water area (% of total land area) |
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EN_RSRV_MXWAN Reservoir maximum water area (square kilometres) |
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EN_RSRV_MXWAP Reservoir maximum water area (% of total land area) |
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EN_WBE_WTLN Wetlands area (square kilometres) |
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EN_WBE_WTLP Wetlands area (% of total land area) |
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EN_WBE_MANGN Mangrove area (square kilometres) |
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EN_WBE_MANGC Mangrove total area change (%) |
Sources of information: Data on aquatic ecosystems is collected by line ministries and institutions (e.g. Environment, Water, and Natural Resources), universities and research institutions, NGOs and citizens’ science initiatives (ground-based surveys) and space agencies (Earth observations). A combination of national data, literature search and data based on satellite images is used to produce the sub-indicators.
Related SDG Indicators: 6.3.2 (Proportion of bodies of water with good ambient water quality), 6.4.1 (Change in water-use efficiency over time), 6.4.2 (Level of water stress: freshwater withdrawal as a proportion of available freshwater resources), 6.5.1 (Degree of integrated water resources management), 6.5.2 (Proportion of transboundary basin area with an operational arrangement for water cooperation), 15.1.2 (Proportion of important sites for terrestrial and freshwater biodiversity that are covered by protected areas, by ecosystem type), and 15.3.1 (Proportion of land that is degraded over total land area).
2. Data availability by region, SDG Global Database, as of 02 July 2025
3. Proposed disaggregation, links to policymaking and its impact
| Proposed disaggregation | Link to policymaking | Impact |
|---|---|---|
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Change in the extent of water-related ecosystems over time, by river basin (%)(Hydrosheds 2023):
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River basins are the most appropriate scale to address the geographical, hydrological and ecological characteristics of water resources and related human activities and needs. This disaggregation tracks the extent of water-related ecosystems over time, by type of ecosystems and by river basins. Such information about where and why changes in the extent of aquatic ecosystems are occurring is useful to ensure the continued provision of ecosystem services. It provides a sound basis that enables informed decisions at national and local levels for the protection and restoration of water bodies. This disaggregation is consistent with the Ramsar Convention (Ramsar Convention on Wetlands n.d.) and contributes to the UN Water Action Decade (UNGA 2017b) and the SDG 6 Global Acceleration Framework (UN-Water 2020). |
Water-related ecosystems are among the most biologically diverse ecosystems and they provide multiple goods and services to society, the economy and the environment. Human development depends largely on the integrity and quality of those ecosystems. Though, many aquatic ecosystems, particularly wetlands, are under severe pressures resulting in biodiversity loss and the degradation of associated ecosystem services. Thus, their protection and restoration are critical and need to be strengthened, not only for environmental considerations (including the protection of other ecosystems like terrestrial ecosystems and oceans). But more broadly for the achievement of sustainable development to respond to human and economic needs, poverty reduction and gender equity objectives, and the strengthening of climate resilience and adaptative capacity (UNEP 2021c; UN 2022a). |