Preliminary Results of Survey on Requirements for Essential Water Variables (EWVs)

Preliminary results are presented from a new survey on observations of Essential Water Variables (EWVs) required for global water cycle research and applications in monitoring and the management of water resources. Generalized requirements are set forth by organizations like the international Group on Earth Observations (GEO)—Global Water Sustainability (GEOGLoWS) to establish a standardized approach across the globe. Key aspects considered in the definition of EWVs include:

• Relevance: EWVs should address critical user needs and be informative for specific purposes. This could include monitoring water quantity, quality, or both, depending on the application. And, provide guidance for the improvement of observing and modeling systems.
• Observability: Data collection should be achievable through a combination of ground-based instruments, remote sensing techniques(satellites), and modeling.
• Spatial and Temporal Resolution: Data needs to be collected at appropriate spatial resolution and with sufficient frequency (temporal resolution) to capture the dynamics of the water system component being monitored.
• Standardization: Data collection methods and formats should be standardized to ensure consistency and facilitate data sharing and integration from various sources.
• Sustainability: EWV monitoring programs should ensure the continuity and usefulness of the data collected.
• Main purpose of Survey: Consolidate/update Requirements for EWVs for GEOGLOWS (Water Sustainability), GEO-WEF (Water-Energy-Food Nexus), UN-SDGs (Sustainable Development), UN-FCCC (Climate Change).
• This survey builds on the GEOSS Water Strategy Report(https://ceos.org/document_management/Ad_Hoc_Teams/WSIST/WSIST_GEOSS-Water-Strategy-Full-Report_Jan2014.pdf), and the Global Water Sustainability(GEOGLoWS) Initiative of GEO (https://www.geoglows.org/)d---- Discussed further in “Implementing the GEOSS water strategy: from observations todecisions. Richard Lawford, Sushel Unninayar, George Huffman, Wolfgang Grabs, Angelica Gutierrez, Chu-Ishida-Watanabe, Int. Journal of Digital Earth, Taylor &Francis. April 2023.
• To improve the statistical robustness of the Survey, we would appreciate

your filling out the survey: https://forms.gle/C4DKtwhTVf6qpmbx8.