WaterOneFlow Web Services & WaterML

Web services are computer applications that interact with and exchange information with other applications over the internet. The CUAHSI-HIS uses a family of web services, called WaterOneFlow, that have been developed as a standard mechanism for the TRANSFER of hydrologic data between hydrologic data servers (databases) and users. Web services streamline the often time consuming tasks of extracting data from a data source, transforming it into a usable format and loading it in to an analysis environment. Web services format the data as XML and the specific variety of XML that is generated by the WaterOneFlow web services is known as CUAHSI WaterML. The specifics of WaterML are documented in the OGC™ Discussion Paper, CUAHSI WaterML [PDF; 296K; 86 pages].

Draft WaterML Documentation — Open for Commentary:

These are draft documents that are currently in the review process and we invite the water community to help us review them and provide commentary. You can submit your comments using our feedback page.

WaterOneFlow Resources:

WaterML Resources:

Web Service Functions:

WaterML defines the following set of WaterOneFlow web service functions. Due to the custom nature of the implementqation of WaterOneFlow for different data sources, not all functions are available for all sets of web services.

  • GetSiteInfo — Given a site number, this method returns the site's metadata.
  • GetSiteInfoObject — Given a site number, this method returns the site's metadata.
  • GetSites — Given an array of site numbers, this method returns the site metadata for each one.
  • GetSitesXml — Given an array of site numbers, this method returns the site metadata for each one.
  • GetVariableInfo — Given a variable code, this method returns the variable's name.
  • GetVariableInfoObject — Given a variable code, this method returns the variable's siteName.
  • GetValues — Given a site number, a variable, a start date, and an end date, this method returns a time series.
  • GetValuesObject — Given a site number, a variable, a start date, and an end date, this method returns a time series.

CUAHSI Water Data Services:

The CUAHSI-HIS project has identified a number of 3rd-party data sources that are of value to the hydrologic data community, and have negotiated a variety of access arrangements to provide WaterOneFlow web service access to this data in a standard way. The following web services are hosted at HIS Central. Generally the data underlying these web services are maintained by the originating organization, however metadata catalogs have been developed and are hosted at HIS Central to index and support some of these web services.

  • USGS NWIS Daily Value Data (Discharge; Daily Averaged Real Time Data) — The USGS National Water Information System (NWIS) provides access to millions of sites measuring streamflow, groundwater levels, and water quality. This web service provides methods for retrieving daily values data, such as discharge and water levels, from NWIS. For more information about NWIS, see the NWIS home page at http://waterdata.usgs.gov/nwis.
  • USGS NWIS Ground Water Data — The USGS National Water Information System (NWIS) provides access to millions of sites measuring streamflow, groundwater levels, and water quality. This web service provides methods for retrieving Ground Water data from NWIS. For more information about NWIS, see the NWIS home page at http://waterdata.usgs.gov/nwis.
  • USGS NWIS Unit Values Data (Real Time) — The USGS National Water Information System (NWIS) provides access to millions of sites measuring streamflow, groundwater levels, and water quality. This web service provides methods for retrieving Real Time data from NWIS. For more information about NWIS, see the NWIS home page at http://waterdata.usgs.gov/nwis.
  • USGS NWIS Instantaneous Irregular Data (Field Measuements; Water Quality) — The USGS National Water Information System (NWIS) provides access to millions of sites measuring streamflow, groundwater levels, and water quality. This web service provides methods for retrieving Water Quality data from NWIS. For more information about NWIS, see the NWIS home page at http://waterdata.usgs.gov/nwis.
  • EPA STORET (STOrage and RETrieval) — STORET is a repository for water quality, biological, and physical data and is used by state environmental agencies, EPA and other federal agencies, universities, private citizens, and many others. For for information see: http://www.epa.gov/storet/.
  • USDA-NRCS SNOTEL — NRCS operates a systems to collect snowpack and related climatic data in the Western United States and Alaska. For more information see: http://www.wcc.nrcs.usda.gov/snotel/.
  • ORNL DAYMET Meteorological Model — Daymet is a model that generates daily surfaces of temperature, precipitation, humidity, and radiation over large regions of complex terrain. Daymet was developed at the University of Montana, Numerical Terradynamic Simulation Group (NTSG) at http://www.ntsg.umt.edu, to fulfill the need for fine resolution, daily meteorological and climatological data necessary for plant growth model inputs. Operated by the National Center for Atmospheric Research.
  • NOAA-NCDC/NWS ASOS (Automated Surface Observing System) — The ASOS program is a joint effort of the National Weather Service (NWS), the Federal Aviation Administration (FAA), and the Department of Defense (DOD). The ASOS systems serves as the nation's primary surface weather observing network. ASOS is designed to support weather forecast activities and aviation operations and, at the same time, support the needs of the meteorological, hydrological, and climatological research communities. For more information see: http://www.nws.noaa.gov/asos/.
  • NASA MODIS (Moderate Resolution Imaging Spectroradiometer) — MODIS is a key instrument aboard the Terra (EOS AM) and Aqua (EOS PM) satellites. Terra's orbit is timed so that it passes from north to south across the equator in the morning, while Aqua passes south to north over the equator in the afternoon. Terra MODIS and Aqua MODIS are viewing the entire Earth's surface every 1 to 2 days, acquiring data in 36 spectral bands, or groups of wavelengths (see MODIS Technical Specifications). More information can be obtained at: http://modis.gsfc.nasa.gov/about/.
  • NCEP NAM (North American Mesoscale) 12K — Data from the NCEP North American Mesoscale (NAM) Weather Research and Forecasting (WRF) model. More information can be obtained at: http://www.meted.ucar.edu/.

3rd-Party WaterML Web Services:

The following 3rd-party data sources have developed versions of WaterOneFlow web services that share data using the CUAHSI WaterML format directly from their own servers:

Each data network has it's own set of web services. CUAHSI-HIS maintains a central registry of all public WaterOneFlow web services.

Online HTML XML Schema Documentation

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