Observations Data Model

Tim Whiteaker, CRWR

The CUAHSI Hydrologic Information System project is developing information technology infrastructure to support hydrologic science. One aspect of this is a data model for the storage and retrieval of hydrologic observations in a relational database. The purpose for such a database is to store hydrologic observations data in a system designed to optimize data retrieval for integrated analysis of information collected by multiple investigators. It is intended to provide a standard format to aid in the effective sharing of information between investigators and to allow analysis of information from disparate sources both within a single study area or hydrologic observatory and across hydrologic observatories and regions. The observations data model is designed to store hydrologic observations and sufficient ancillary information (metadata) about the data values to provide traceable heritage from raw measurements to usable information allowing them to be unambiguously interpreted and used. A relational database format is used to provide querying capability to allow data retrieval supporting diverse analyses. A generic template for the observations database is presented. This is referred to as the Observations Data Model (ODM).

Click on the thumbnail above to view a diagram of the ODM.

The ODM organizes data into roughly three areas: Sites (where variables are measured), Variables (units, sampling methods, etc.), and DataValues (time series of data along with qualifiers and other record level metadata.) Additionally, the ODM includes a series catalog, providing a quick view into the time series stored in the database.

For more information about the ODM, visit the ODM page at http://water.usu.edu/cuahsi/odm/default.aspx. This page includes substantial documentation about the ODM, as well as a set of ODM Tools for working with ODM databases.