USU NIDIS Drought Server Update

Jeff Horsburgh, Kim SchreudersDavid 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

NWISWOF

SNOTELWOF

USBR ReservoirWOF

NCDC PrecipWOF

SNODASWOF

Harvest UtilityGet 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

GISFramework

Time Series Analyst

Overall System Architecture

• Set of query functions • Returns data in WaterML

Zaslavsky et al., 2007, OGC 07-041r1, http://portal.opengeospatial.org/files/?artifact_id=21743

WaterML and WaterOneFlowWaterML is an XML language for communicating water dataWaterOneFlow is a set of web services based on WaterML

CUAHSI Web Services Established for Primary Data Sources

• USGS NWIS – daily streamflow– http://river.sdsc.edu/wateroneflow/NWIS/DailyValues.asmx

• USDA NRCS SNOTEL – 6 standard variables including SWE– http://drought.usu.edu/SNOTEL/cuahsi_1_1.asmx

• NCDC Precipitation – precipitation data only– http://drought.usu.edu/NCDC/cuahsi_1_1.asmx

• USBR Reservoirs – storage, elevation, inflow, outflow– http://drought.usu.edu/USBRReservoirs/cuahsi_1_1.asmx

• SNODAS HUC8,10,12 – snow water equivalent– http://drought.usu.edu/SNODAS_HUC8/cuahsi_1_1.asmx– http://drought.usu.edu/SNODAS_HUC10/cuahsi_1_1.asmx– http://drought.usu.edu/SNODAS_HUC12/cuahsi_1_1.asmx

The foundation of the system: multiple data sources with common interfaces and a common data transmission language (WaterML)

WaterOneFlow Web Services For Agency Data2 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

GetSitesGetSiteInfo

GetVariablesGetVariableInfo

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 DataDrought 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

BQ1

Q2

S1

Q1

Q2

S1

RA=Q1/AA

RB=(Q2- Q1-S1)/AB

H1

H2

H3

a1

a2A

a2B

a3

RH1=RB

RH2=(a2ARA +a2BRB)/(a2A +a2B)RH3=RB

QH1=RH1a1

QH2=RH2a2 (a2=a2A+a2B) QH3 =RH3a3+QH1+QH2

Gage subwatershed unit runoff

HUC 10 unit runoff

HUC 10 available streamflow (everything upstream)

Measured flow and storage

Precipitation interpolation and adjustment

Precipitation interpolationA(x) - Smoothed mean annual precipitation at location x (PRISM) Pi - Time step precipitation at gauge location xi

iP = A(xi) - Mean annual precipitation at gauge i.

P(x) - Time step precipition at (non gauge) location x.

Ni = Pi/ iP - Normalized time step precipitation at gauge i.

igauges

ii N)x()x(N

Weight or basis function for linear interpolation of normalized precipitation at location x from gauges at nodes of the encompassing Delauney triangle

P(x) = N(x) A(x) - Precipitation estimate for location x.

igauges igaugesiii

ii

igaugesii P)x(wP

P

)x(A)x(N)x(A)x(

Over subwatershed

igaugesii

igaugesii PwbPdx)x(wPb

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 Websitehttp://drought.usu.edu/hydroserverwebsite/

Map Application and Time Series Analysthttp://drought.usu.edu/nidismap/

http://hydroserver.codeplex.com

http://hydrodesktop.codeplex.com

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

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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