CUAHSI Hydrologic Information Systems and Web Services By David R. Maidment With support from many collaborators: Ilya Zaslavsky, David Valentine, Reza Wahadj, Chaitan Baru, Praveen Kumar, Michael Piasecki, Rick Hooper, Jon Duncan, David Tarboton, Jeff Horsburgh, Venkat Lakshmi, Chunmaio Zheng, Xu Liang, Yao Liang, Ken Reckhow, Upmanu Lall, LeRoy Poff, Dennis Lettenmaier, Barbara Minsker, …… And many graduate students and post-docs: Venkatesh Merwade, Tim Whiteaker, Jon Goodall, Gil Strassberg, Ben Ruddell, Luis Bermudez, Bora Beran, …… Thanks to everyone for all their help!

HIS Goals Hydrologic Data Access System – better access to a large volume of high quality hydrologic data Support for Observatories – synthesizing hydrologic data for a region Advancement of Hydrologic Science – data modeling and advanced analysis Hydrologic Education – better data in the classroom, basin-focused teaching

HIS User Assessment (Chapter 4 in Status Report) Data Access Science Observatory support Education Which of the four HIS goals is most important to you?

HIS Goals Hydrologic Data Access System – better access to a large volume of high quality hydrologic data Support for Observatories – synthesizing hydrologic data for a region Advancement of Hydrologic Science – data modeling and advanced analysis Hydrologic Education – better data in the classroom, basin-focused teaching

Rainfall & Snow Water quantity and quality Remote sensing Water Data Modeling Meteorology Soil water

Water Data Web Sites

NWISWeb site output # agency_cd Agency Code # site_no USGS station number # dv_dt date of daily mean streamflow # dv_va daily mean streamflow value, in cubic-feet per-second # dv_cd daily mean streamflow value qualification code # # Sites in this file include: # USGS NEUSE RIVER NEAR CLAYTON, NC # agency_cdsite_nodv_dtdv_vadv_cd USGS USGS USGS USGS USGS USGS USGS USGS USGS USGS USGS Time series of streamflow at a gaging station

CUAHSI Hydrologic Data Access System A common data window for accessing, viewing and downloading hydrologic information USGS NASANCDC EPANWS Observatory Data

Observation Stations Ameriflux Towers (NASA & DOE)NOAA Automated Surface Observing System USGS National Water Information SystemNOAA Climate Reference Network Map for the US

NWIS Station Observation Metadata Describe what has been measured at this station

Web Page Scraping Programmatically construct a URL string as produced by manual use of the web page Parse the resulting ASCII file

CUAHSI Web Services Web Services Library Web Application: Data Portal Your application Excel, ArcGIS, Matlab Fortran, C/C++, Visual Basic Hydrologic model ……………. Your operating system Windows, Unix, Linux, Mac Internet Simple Object Access Protocol

Series and Fields Features Point, line, area, volume Discrete space representation Series – ordered sequence of numbers Time series – indexed by time Frequency series – indexed by frequency Surfaces Fields – multidimensional arrays Scalar fields – single value at each location Vector fields – magnitude and direction Random fields – probability distribution Continuous space representation

mm / 3 hours Precipitation Evaporation North American Regional Reanalysis of Climate Variation during the day, July 2003 NetCDF format

Arc Hydro Time Series Feature Class (HydroID) Attribute Series Table (FeatureID) HydroID 2906 Geospatial features associate with time series

TSDateTime FeatureID TSType TSValue Arc Hydro Time Series Object TSType Table Feature Class (point, line, area)

Time Space (x,y,z) Variable Value NetCDF Data Model Attributes Dimensions and Coordinates

NWIS ArcGIS Excel NCAR Unidata NASA Storet NCDC Ameriflux Matlab AccessSAS Fortran Visual Basic C/C++ Some operational services CUAHSI Web Services Data Sources Applications Extract Transform Load

Core Web Services ServiceInputOutput GetSites Obs NetworkAll station codes in network GetSiteInfo Station CodeLat/long, station name GetVariables Obs Network or data source All variable codes GetVariableInfo Variable codeDescription of variable GetValues Station code or lat/long point, variable code, begin date, end date A time series of values GetChart As for GetValueA chart plotting the values

Operational Services Service AmerifluxDaymetMODISNWISNAM GetSites Yes GetSiteInfo Yes GetVariables Yes GetVariableInfo Yes GetValues Yes GetChart Yes

CUAHSI Web Services NCEP North American Forecast Model 12 Km grid for continental US

Water OneFlow Like Geospatial OneStop, we need a “Water OneFlow” – a common window for water data and models Advancement of water science is critically dependent on integration of water information Federal Academic Local State

Conclusions It would be good to define a collaboration between CUAHSI and Unidata for web services that has a consistent vocabulary We in CUAHSI would defer to Unidata for definition of how to ingest real-time weather information as fields (netCDF with CF conventions) Try to define services that represent “time histories” of variables, past, present and future e.g. precipitation, evaporation, surface temp