Mapping Freshwater Ecosystem Services for Human Water Security

The majority of the world’s population is dependent on freshwater provisions from threatened upstream water sources, with 82% of the world’s population served by upstream areas exposed to the highest levels of threat. Industrialized countries are often successful in offsetting threats on their freshwater provisions via infrastructure investments, realizing up to 70% reductions in threat. However, the least developed countries, due to economic constraints, realize fewer gains in threat abatement (<20% threat reduction) employing traditional engineering solutions. Developing countries, although highly constrained in their capacity to mobilize hard infrastructure investments, represent a significant global opportunity for adopting new and innovative nature-based or green water management approaches that could simultaneously promote human well-being and environmental benefits at a lower costs than traditional engineering.

Map depicts four threat development states where HWS threat on freshwater provisions supporting downstream users have: (red) stayed under persistent High threat, (orange) transitioned to High threat due to limited infrastructure investments, (green) improved from High to Low/Moderate threat as a result of investments in water infrastructure, or (blue) maintained relative health under Low/Moderate threat.

Our analysis, reported in the September 2015 issue of Global Environmental Change, presents a new global framework that not only maps the state of freshwater resources and levels of service it conveys to downstream users throughout the world but also provides a critical tool to prioritize national investments to better manage these valuable resources. This study provides the first global-scale functional framework to assess opportunities for blending nature-based solutions with traditional engineering infrastructure, to secure and safeguard freshwater provisions for downstream populations. This is particularly important for the most economically disadvantaged who stand to benefit the most from finding cheaper and therefore realistic solutions to address their water security threats. The paper argues that improving the management of the threatened upstream freshwater sources in the less developed countries would allow the majority of the global population to move away from short-term and expensive engineering solutions.

Banner image: The Danube River in Central Europe [photo courtesy of Darlene Dube].