The CUAHSI Observations Data Model

Jeff Horsburgh7-9-2007

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

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

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.)

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 towerdata

Precipitation& Climate

Groundwaterlevels

Water Quality

Soil moisture

dataODM

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

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

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