Essential Water Variables (EWV)

Essential Water Variables (EWV) are defined as water variables/parameters that address “user”-defined critical requirements for one or more of the following:

• Observational “monitoring” of key elements of the global and regional/local water cycle,
• Observations required by diagnostic and/or land surface/hydrological prediction models that are used to generate derived products for the end-user communities,
• Observational and model-derived variables and parameters required by users of water data/information products as applied to various inter-disciplinary decision support systems and tools

(JAXA and GEO 2014)