The SDGs target protection of water-related ecosystems, but how do we measure progress?

Challenges facing water-related ecosystems

In pursuit of development, societies across the globe have negatively impacted water related ecosystems. A shocking example of this is that the rate of loss of global wetlands between 1900 and 2000 is estimated to be around 69-75% (Davidson 2014, see Figure 1). 40% of the loss occurred between 1970-2008, according to the 2015 Ramsar Convention on Wetlands. Increased water abstraction for growing urban populations was partly to blame, as was the transformation of wetlands – lands saturated by water, such as marshes or river deltas – into arable agricultural land.

Wetlands are in fact one of the most productive ecosystems that provide many of the services that society depends on, ranging from provision of food and water, regulation of flows of water, recycling of nutrients and waste,and cultural benefits, such as spiritual, recreational or educational uses.

Figure 1 illustrates the rate of decline of wetlands. Given the importance of these ecosystems, a massive global effort is required to restore and protect them, and for this the SDG 6.6.1 Indicator method seeks to collect the necessary information. But a significant question remains: what are the best ways to gather and assess this data?

Water-related ecosystems and the SDGs

Water-related ecosystems, including  mountains, forests, wetlands, rivers, aquifers, and lakes, are vital to providing social and economic benefits for people. The declining condition of the ecosystems directly impacts water availability as well as other essential services such as biodiversity, food production and flood control. For that reason, Target 6.6  - By 2020, protect and restore water-related ecosystems, including mountains, forests, wetlands, rivers, aquifers and lakes - is set to contribute to the achievement of Goal 6.  In service of that, indicator 6.6.1 - Change in the extent of water-related ecosystems over time - and its component sub indicators, will be used to monitor management performance in relation to the target.

How are water-related ecosystems monitored for the SDGs?

Monitoring of Target 6.6 represents what could become the world’s largest initiative to monitor and report on water-related ecosystems. This builds substantially on the monitoring of the spatial extent of wetlands that has been developed by the Ramsar Convention of Wetlands by including measures of quantity, quality and ecosystem health.

A report published by IWMI and WLE provides guidance to countries on the method used for reporting SDG Indicator 6.6.1, which monitors the “change in extent of water-related ecosystems over time.”  This guideline supports the abbreviated but official UN Water indicator monitoring method.

The aim of the guideline is to support countries by:

• teaching them to collect and submit data on SDG 6.6.1 as part of their contribution to sustainable development
• providing guidance on the methods used to monitor water-related ecosystems
• supporting the management of water resources at a country level.

The guideline responds to each of the sub-indicators illustrated in Figure 3. Guidance is given for monitoring the spatial extent of water-related ecosystems such as vegetated wetlands, rivers and open water bodies such as lakes, artificial reservoirs, and groundwater aquifers. A large part of this guidance is devoted to techniques that use Earth Observation data to measure change in extent (see the iconic example in Figure 4, showing the loss in extent of the Aral Sea which is a freshwater lake).

The amount of water stored in a given ecosystem is another key indicator of ecosystem health.  Quantity is thus reported for rivers and other open water bodies, like lakes and reservoirs, as well as for groundwater.  In addition, monitoring the quality of water over time is crucial for determining any potential negative impacts to the ecosystem and thus to the many services provided by the ecosystem. Lastly, the state or health of the ecosystems is monitored through a system that evaluates the biota (e.g. fish, invertebrates or vegetation) as indicators of overall ecosystem condition. This process of measuring changes in the biotic communities helps society to detect overall changes to the ecosystem (see figure 5 for illustration).

The inclusion of Indicator 6.6.1 as part of the SDG Agenda represents a wonderful opportunity for society to gather and make use of data reflecting the state of water-related ecosystems. This will enable us to better manage these ecosystems in order to secure a sustainable future.  The SDG 6.6.1 step-by-step method is in the process of being implemented globally as part of the Agenda 2030, and this guideline provides much-needed support to those who are involved in this submission or who wish to understand the measures necessary to achieve sustainable development.