WaterML for Hydrologists

The Consortium of Universities for the Advancement of Hydrologic Science, Inc., Hydrologic Information System has developed WaterOneFlow web services, which provide a standard means of accessing the nation's water data. Regardless of the data source, WaterOneFlow always returns data in an XML format called WaterML, which is a web services language for acquiring time series of data on water properties and related quantities from data archives. Thus, the data consumer, instead of having to learn a myriad of data formats for every data source accessed, only needs to learn a single format, WaterML. This paper explains WaterML from a data consumer's perspective. This is for the hydrologist who wants to download and use WaterML data, not for the data publisher who wants to make water data accessible on the web. The paper does not delve into the technical details of the WaterML schema, but rather describes the basic parts of a WaterML file so that a hydrologist can download WaterML and make use of it.