Methodology
The Aqueduct Water Risk Atlas maps aggregated scores of 12 key water indicators in 15,000 watersheds around the world. This page provides a brief description of the indicators and aggregation. For more complete documentation of the Aqueduct Water Risk Atlas, you can download the Framework document and indicator metadata.
WRI is committed to the continued improvement of Aqueduct indicators and methodology. To submit comments or feedback please contact us.
Aqueduct Water Risk Framework
The Aqueduct Water Risk Framework brings together 12 indicators into three categories of water risk and an overall aggregated score. The framework is based on a thorough review of the literature and available global data, and includes several indicators developed exclusively for Aqueduct. It is structured, in particular, to help companies and investors understand indicators of water-related risk to their business, but is intended for all users, including government and civil society to better understand geographic water issues.
As of October 2018, the Overall Water Risk aggregation has been optimized to better reflect the distribution of results. Contact leah.schleifer@wri.org with any questions.
Indicator and Data Selection
Aqueduct’s 30+ data sources were selected following extensive literature review and expert consultation. Criteria for selection include:
- Relevance to water users and water managers
- Robustness of data collection methodology
- Global coverage
- Granularity
- Timeliness of publications
- Length of time covered
For more information on Aqueduct's data sources and indicators, please see the indicator metadata document.
Aggregated Scores
We calculate aggregated overall water risk scores for each watershed around the world using a weighted average. First, we normalize each watershed's water risk score for each indicator to a scale of 0–5. Then we combine each score using a weighted average to create an aggregated, overall water risk score.
Weights
Each water risk indicator can be weighted to determine how much influence that indicator has on the overall water risk map. The customizable weights reflect the importance and relevance of each indicator to the user. Aqueduct provides a default set of weights as well as preset weights for major industry sectors based on information provided in corporate water disclosure initiatives and input from water experts. Since exposure to water risk depends on the characteristics of the water user, we encourage users to customize the weights to reflect their level of exposure to each indicator.