Point Observations Information Model

1
Point Observations Information Model
USGS
Data Source
Network
Streamflow gages
Sites
Neuse River near Clayton, NC
Variables
Discharge, stage (Daily or instantaneous)
Values
Value, Time, Qualifier
206 cfs, 13 August 2006

• A data source operates an observation network
• A network is a set of observation sites
• A site is a point location where one or more
  variables are measured
• A variable is a property describing the flow or
  quality of water
• A value is an observation of a variable at a
  particular time
• A qualifier is a symbol that provides
  additional information about the value

2
Data Source and Network
Controlled Vocabulary Tables
Sites
Variables
Values
Metadata
e.g. mg/kg, cfs
e.g. depth
Streamflow
Depth of snow pack
Landuse, Vegetation
e.g. Non-detect,Estimated,
Windspeed, Precipitation
A site is a point location where one or more
variables are measured
A data source operates an observation network
A network is a set of observation sites
A variable is a property describing the flow or
quality of water
A value is an observation of a variable at a
particular time
Metadata provide information about the context of
the observation.
Data Discovery
Data Delivery
Observations Data Model Schema (version 4.0)
Ernest To Center for Research in Water
Resources University of Texas at Austin 20061011