1. The CUAHSI Observations Data Model Jeff Horsburgh 7-9-2007 David Maidment, David Tarboton, Ilya Zaslavsky, Michael Piasecki, Jon Goodall, David Valentine, Tom Whitenack, Tim Whiteaker, Bora Beran, Ernest To http://www.cuahsi.org/his.html

2. Primary Use Cases Relational data model underlying the CUAHSI Hydrologic Information System –Observation catalogs for national datasets (USGS NWIS, EPA STORET) and web services –Standardization of investigator data management in environmental observatories

3. What is an Observation? An observation is an event that results in a value describing some phenomenon (OGC Observations and Measurements, 2006) ODM focuses on observations made at a point Types: grab samples for laboratory analysis, physical measurements from field instruments, streaming data from in-situ sensors Not covered – observation fields (e.g., grids, images, etc.)

4. ODM Overview A relational database at the single observation level (atomic model) Stores observation data made at points Metadata for unambiguous interpretation Traceable heritage from raw measurements to usable information Standard format for data sharing Cross dimension retrieval and analysis Streamflow Flux tower data Precipitation & Climate Groundwater levels Water Quality Soil moisture data ODM

6. Associated Tools Data Loaders –ODM Data Loader –Streaming Data Loader ODM Tools –Query and export – export data series and metadata –Visualize – plot and summarize data series –Edit – delete, modify, adjust, interpolate, average, etc. Controlled Vocabularies –Online moderated system

7. Associated Tools ODM Web Services –WaterML Data Access System for Hydrology (DASH) –A common data window for accessing, viewing and downloading hydrologic information HydroSeek –Ontology based search engine

8. Model Extensibility The ODM schema is generic, but the controlled vocabularies are not –Variable names, data types, units, etc. ODM controlled vocabularies are editable via a moderated system online Working on ODM API to shield applications from changes to the database schema