1 GEO Task US-09-01a Water SBA SBA: Water Analyst: Dr. Sushel Unninayar Current Status of Report: Draft Final: Awaiting final feedback from GEO-UIC as regards the final disposition of this report, and further iterations as needed with the AG, CoP and other entities such as the IGWCO, CEOS. Date Final Report will be completed: Further action/steps on this report awaits decisions by the Task US-09-01a and GEO-UIC

Sub-Areas Analyzed List sub-areas chosen for analysis: (1) Surface Waters and Fluxes (Primarily, Land Surface Water Cycle Processes); (2) Ground Water Processes (Including Recharge/Discharge & Regolith Processes…); (3) Forcing Elements on Terrestrial Hydrology (E.g., Surface Meteorology/Hydromet, Surface Radiation budget and Clouds, etc …) (4) Water Quality & Water Use (Including Organic, Inorganic, Isotopic & Nutrient/Contaminant Fluxes, and E.g., Water Demand/Draw/Regulation etc……) [Each Sub-Area involves over 20 water cycle parameters/variables with a total over of over 100] 2

Prioritization Methodology Describe methodology used to prioritize parameters, both within sub-areas (if applicable) and in Section 2.6 (Prioritization) and Chapter 5 (overall): Ranking based on the following: End user needs and requirements (over 75 user sectors, and over 100 parameters/variables were considered and analyzed) Observations required to derive information products that deliver applications of societal benefit Critical observations needed to understand and characterize the physical/dynamical structure of the global/regional/local water cycle system Consideration of both system “state” variables and “forcing” variables, the latter needed by users to determine variability and change 3

Analyst Feedback on Methodology List pro’s and con’s of prioritization methodology. Pro’s: The prioritization “ranking” of critical parameters/variables per end user sector of high, medium, low, and N/A is considered robust due to the extensive sample size of the referenced documentation (over 200) and the collective expertise of the analyst, the AG and CoP, and the knowledge base carried by operational service providing agencies and organizational entities (global, regional, local) Con’s: There is a subjective element to the prioritization in that the very end-users (e.g., irrigation engineer or reservoir manager…) have not been directly contacted—beyond the scope of this exercise. Their input is inferred through service providing agencies and document references. Is the prioritization methodology broadly applicable (e.g., for other SBAs or the cross-SBA analysis), or specific to your SBA? Yes: Broadly applicable, and recommended Would you recommend this methodology for other US reports in the future? (either as is, or in a modified form?): Yes 4

Priorities Identified Number of priority parameters identified: List parameters from Chapter 5, and note whether they are in priority order, no order, tiered lists, etc. (use 2 nd slide as needed): Sub-Area#1: Surface Waters, Fluxes, and Processes: Precipitation (liquid/snow/ice) Soil Moisture/Temperature (Surface and Vadose Zone) Evaporation and Evapotranspiration Runoff & Stream Flow/River Discharge/Stage… Lake/Reservoir-Area/Level/Depth…. Snow/Ice Cover & Depth/SWE & Freeze-Thaw Margins,…. Glaciers/Ice Sheets, Permafrost, Frozen Ground— Area/Depth/Mass balance… 5

Sub-Area#2: Ground Water (Including Recharge/Discharge & Regolith Processes) Ground Water Table and Charge/Recharge Rates Aquifer Levels, Geologic Stratification, Volumetric… Soil type/Texture, Composition, Porosity/Conductivity.. Sub-Area#3: Forcing Elements (e.g., Surface Meteorology, Surface Radiation Budgets and Clouds) SW, LW Surface Radiation Budgets, Albedo, Emissivity, and Clouds Surface Air Temperature, Relative Humidity/Specific Humidity, Winds, Pressure.. Vegetation Cover/Type, Land Cover & Land Use Topography and/or Geology 6

Sub-Area#4: Water Quality and Use Water Quality/Composition—Organic/Inorganic/Isotopic Nutrient and Contaminant Effluents/Fluxes into Water Bodies Water Sources, Water Demand/Use & Regulation Other Required Data Products: Observational time series and statistics including paleo/proxy Dynamical/statistical model output/amalyses Decision support information/output 7

Interpretation of Results Note any “themes” that emerged, surprising or expected conclusions, considerations for incorporating results into Cross-SBA Analysis. Considerations for incorporating results into Cross-SBA Analysis: TBD depending on the objective and criterion used for the Cross- SBA Analysis. Surprising conclusions: None Expected: Deficiencies in previous statements on priority observations. These deficiencies were notes and corrected in this analysis 8

Limitations/ Caveats Additional notes about interpretation of priority results – i.e., inherent biases, gaps, overlaps with other SBA reports, etc. Interpretation: Priority ranking for each observational variable/parameter is user sector dependent. See Table 4 for details. Thus, global summarization could lead to misleading results. Summarizing/integration across SBA’s could also lead to faulty conclusions. Overlaps: The water cycle is fundamental to all aspects of the Earth/Climate system. Overlaps are particularly conspicuous with SBA-Weather, SBA-Climate, and various aspects of other SBA’s such as Energy, Agriculture, Disasters, Human Health, Ecosystems, Biodiversity. 9