The Observations Data Model

A diagram of the Observations Data Model schema.

Much of the data in HIS is stored in the Observations Data Model (ODM), which is a relational database schema that has been designed specifically for storing and retrieving water data. This schema, which can be seen above, is star-shaped with a table for DataValues at the center. In addition to storing data values, this table also holds a number of keys that provide connections to other tables in the schema such as the Sites and Variables tables.

Unique tools have been developed to load and interact with data stored in an ODM database. These include the ODM Data Loader, ODM Streaming Data Loader, and ODM Tools. These applications enable data publishers to load data into an ODM database in addition to providing the abilities to visualize, query, and edit data in the database.

In addition to querying and exporting data...

...ODM Tools can be used to visualize data stored in an ODM database.

For a more detailed look at the Observations Data Model, see this article in Water Resources Research:

Horsburgh, J. S., D. G. Tarboton, D. R. Maidment and I. Zaslavsky, (2008), A Relational Model for Environmental and Water Resources Data, Water Resources Research, 44: W05406, doi:10.1029/2007WR006392.