USU NIDIS Drought Server Update Jeff Horsburgh, Kim Schreuders David Tarboton, Stephanie Reeder Avirup Sen Gupta

Goals CUAHSI HydroServer – Data Publication CUAHSI HydroDesktop – Data Access and Analysis Enhance access to drought related data Enable custom drought index evaluation Lake Powell Inflow and Storage

Aggregated Data Values ODM NWIS WOF SNOTEL WOF USBR Reservoir WOF NCDC Precip WOF SNODAS WOF Harvest Utility Get Data and Aggregate to Monthly and Half Monthly Calculate Data Distributions Calculate Drought Index Values WOF HydroDesktop Displays “published” drought index values Calculates and displays “personal” index values Map Application (ArcGIS Server) ESRI Base Map Services Hosted Map Services GIS Framework Time Series Analyst Overall System Architecture

Set of query functionsReturns data in WaterML Zaslavsky et al., 2007, OGC r1, WaterML and WaterOneFlow WaterML is an XML language for communicating water data WaterOneFlow is a set of web services based on WaterML.

CUAHSI Web Services Established for Primary Data Sources USGS NWIS – daily streamflow – USDA NRCS SNOTEL – 6 standard variables including SWE – NCDC Precipitation – precipitation data only – USBR Reservoirs – storage, elevation, inflow, outflow – SNODAS HUC8,10,12 – snow water equivalent – – – The foundation of the system: multiple data sources with common interfaces and a common data transmission language (WaterML)

WaterOneFlow Web Services For Agency Data 2 Different Modes Catalog Metadata Harvester WaterOneFlow Web Service Mode 1: Pass Through (NWIS, SNOTEL, USBR) Mode 2: Store and Serve (NCDC, SNODAS) Catalog + Data Metadata and Data Harvester WaterOneFlow Web Service GetSites GetSiteInfo GetVariables GetVariableInfo GetValues Agency Website or Web Service Providing Data WaterML

Primary data sources accessible in HydroDesktop

Value added data Level 1 – original agency data collected at points (USGS gages, SNOTEL Sites, etc.) Level 2 – time aggregated Level 1 data, monthly and half monthly Level 3 – spatial aggregation of Level 2 data for each drought index input variable at HUC10 level Level 4 – drought index values calculated for HUC10s based on Level 3 values

Ongoing Web Service Work Reservoirs – working with CBRFC to get access to all of the reservoir data that they have, not just USBR reservoirs (this would be a new service) SNODAS – we have loaded everything they have given us, but need to figure out how to update

Time Aggregated Level 2 Data Level 1 data harvested from the WaterOneFlow web services Level 1 data are aggregated based on data type – e.g., sum, ending value – Monthly – Half monthly Published using a WaterOneFlow web service Provide the time aggregated data that serve as inputs for calculating Level 3 data for each spatial unit for which drought indices can be calculated.

Spatially Aggregated Level 3 Data Drought Index Input Variables for Spatial Units USGS 10 Digit Hydrologic Units (~300 in Upper Colorado) Provide an estimate for each drought index variable for each HUC10 unit – streamflow, reservoir storage, precipitation, snow water equivalent Publish the Level 3 data for each 10 digit HUC using a WaterOneFlow web service.

Spatial Interpolations Streamflow - Gage subwatershed approach – Runoff estimated for gage subwatersheds (adjusted for reservoir storage changes) – Area weighted average runoff calculated for each HUC10 based on area of gage subwatersheds in each HUC10 – Subwatershed streamflow (local contribution) and watershed streamflow (everything upstream) Precipitation – Delaunay triangle interpolation Reservoir Storage Snow Water Equivalent – Delaunay triangle interpolation of SNOTEL Sites with elevation correction? – Use SNODAS data

Calculating available flow for HUC watersheds A B Q1Q1 Q2Q2 S1S1 Q1Q2S1Q1Q2S1 R A =Q 1 /A A R B =(Q 2 - Q 1 -  S 1 )/A B H1H1 H2H2 H3H3 a1a1 a 2A a 2B a3a3 R H1 =R B R H2 =(a 2A R A +a 2B R B )/(a 2A +a 2B ) R H3 =R B Q H1 =R H1 a 1 Q H2 =R H2 a 2 (a 2 =a 2A +a 2B ) Q H3 =R H3 a 3 +Q H1 +Q H2 Gage subwatershed unit runoff HUC 10 unit runoff HUC 10 available streamflow (everything upstream) Measured flow and storage

Precipitation interpolation and adjustment

Precipitation interpolation

Level 4 – Calculated Drought Index Values Use Level 3 data in drought index equations to calculate index values for 10 digit HUCs Publish drought index values as a web service Display visually in the map application – Display 10 digit HUCs colored by drought index values

HydroServer Website

Map Application and Time Series Analyst

This is an open system, with open source development. Contributors and development partners are welcome

Conclusions Framework for a standards based sharing of drought information established Desktop based customization possible Need to incorporate additional drought information content Need to transition to sustainable agency based services 20