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CUAHSI Web Services and Hydrologic Information Systems

By David R. Maidment, University of Texas at Austin

Collaborators: Ilya Zaslavsky and Reza Wahadj, San Diego Supercomputer Center, Tim Whiteaker, Venkatesh Merwade, UT Austin, Steve Ansari, NCDC, Ken Lanfear and Mark Hamill, USGS, Jonathan Goodall, Duke University

WSTB Committee on Integrated Observations for Hydrologic and Related Sciences , Dec 1, 2005

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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

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CUAHSI Hydrologic Data Access System(HDAS)

A common data window for accessing, viewing and downloading hydrologic information

USGS

NASANCDCEPA NWS

Observatory Data

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NWIS Station Information in HDAS

http://river.sdsc.edu/HDAS

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Observation Site Files

Ameriflux Towers Automated Surface Observing System

USGS NWIS Stations Climate Reference Network

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Observation Site Map for US

USGS NWISASOSClimate Research NetworkAmeriflux

+ others…….

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Neuse Basin with all points

NWIS Streamflow and Water Quality

NWIS Groundwater

ASOS

NARR

Ameriflux

8NWIS Streamflow and Water Quality

ASOSNARR

Ameriflux

Filtered Site Map

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http://public.ornl.gov/ameriflux/

Building each web servicerequires a site map anda web services library

Ameriflux site map

Web services library

Ameriflux towers measure vertical fluxes of water, heat, CO2

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NWIS

ArcGIS

Excel

NCAR

LTER

NAWQAStoret

NCDC

Ameriflux

Matlab

Access SAS

Fortran

Visual Basic

C/C++

CUAHSI Web Services

Some operational services

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Direct and Indirect Web Services

• Direct web service– The data agency provides direct querying

ability into its archives through SOAP or OpenDAP (NCDC)

• Indirect web service– CUAHSI constructs a “web page mimic”

service, housed at SDSC, that programmatically mimics the manual use of an agency’s web pages (USGS, Ameriflux)

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HydroObjects Library

• CUAHSI has developed a HydroObjects Library with web service wrappers that know where to access each web service and how to interpret its output

User Application(Excel, ArcGIS, …..)

HydroObjects Librarywith web service wrappers

for NWIS, Ameriflux, NCDC, …

Direct or Indirect web services

Web data

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CUAHSI Web Services Library for NWIShttp://river.sdsc.edu/NWISTS/nwis.asmx

These web services are available now for you to use in your programming

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Accessing Ameriflux data directly from Excel using CUAHSI web services

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Transfer of research results• CUAHSI web services for NWIS were announced at a

cyberseminar on Friday Oct 28• On Wednesday Nov 2, Jason Love, from a private

firm, RESPEC, in Sioux Falls, South Dakota, posted on the EPA Basins list server: “Occasionally one comes across something that is worth sharing; the CUAHSI Hydrologic Information Systems - Web Services Library for NWIS is a valuable tool for those of us interested in rapidly acquiring and processing data from the USGS, e.g., calibrating models and performing watershed assessments.”

• He provided a tutorial on how to use the services from Matlab (which CUAHSI had not developed)

• Technology transfer took less than 1 week!

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Standards are the Key• standards …

– Industry standards already exists:• SOAP = Simple Object Access Protocol• WSDL = Web Service Definition Language

– Hydrologic community must add their own to the mix:• HTSS = Hydrologic Time Series Service• HML = Hydrologic Markup Language

• software development …– If we adopt SOAP and WSDL standards, we can

utilize industry support– Hydrology standards will increase interoperability and

code reuse

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CUAHSI Web Services

Web ServicesLibrary

Web application: Data PortalYour application• Excel, ArcGIS, Matlab• Fortran, C/C++, Visual Basic• Hydrologic model• …………….

Your operating system• Windows, Unix, Linux, Mac

Internet Simple Object Access Protocol

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Impact of Web Services

• CUAHSI web data services are significantly simplifying user access to federal water observation data

• This will increase appreciation of the collective information content of these data

• Next step is to set the data in context of their environment – Digital Watershed

• Web services may turn out to be as important or even supersede web pages as a data delivery mechanism