This page describes the USGS Series Catalog view on disrupter.sdsc.edu. To access these data cubes download the Excel 2007 Book that contains pivot table connections for two cubes. The first sheet has a connection to the USGS cube, and the second sheet has a connection to the EPA STORET data cube. The EPA Storet cube is described at this link
EPA STORET Data Cube.
USGS
This cube was built off of a series catalog. Each series contains the number of observations per site,variable,startdate, and enddate. Each series was discretized by assuming that observations followed a uniform distribution between the startdate and the enddate. For example if we had 100 discharge measurements from a site over 10 days, then the assumption is made that there are 10 observations each day. This discretization process is necessary to build the cube off of series catalog data.
Another aspect about the USGS data cube is the Many to Many relationship between methods and observations. If you use Methods you can see this because the numbers in the columns do not sum up to the total number of observations in the bottom of the column. If you try this with other pivot table items you will see that the numbers in the column sum to the total at the bottom of the column. This is because some observations there is more than one observation associated with it. Contrast this with variable code, each observation only has one variable code associated with it.
Measures are the data, the dimensions determine the kind of queries that can be made. The pivot table interface abstracts most of these details, so if you just want to start exploring the data, you can ignore the following sections.
Measures
Observations: The number of observations made
There are 287315003 observations in this cube.
SeriesDayCount: The total number of days from all of the series
There are 338730500 series days in this cube.
Dimensions
Site
HierarchiesLatitude Bands are bands of 10 degrees
Longitude Bands are bands of 20 degrees
LatitudeBand-Latitude: Drills down to individual latitudes
LatitudeBand-Site-Name: Drills down to individual site names
LongitudeBand-Latitude: Drills down to individual longitudes
LongitudeBand-Site-Name: Drills down to individual site names
State-County-Site: Drills from State to County to site name
AttributesAgencyCode:Contains FL005, NV052, USAID, USBR, USCE, USGS, USNPS, WY003
County: Lots of Counties
DaylightSavingsTime: Y,N, for Yes or No
LatitudeBand:(see above)
LongitudeBand: (see above)
Site: The SiteName, 30013 sites
State: US States and provinces
StationType: Coastal, Diversion, Estuary, etc
TimeZone: AFT, AKST, AST, CST, EET, EST, GST, HST, JST, MST, NZT, PST, ZP11, ZP-11
Timeline
HierarchiesDecade-Day: Drill down path is decade, year, day of year
Decade-Month: Drill down path is decade, year, month, day of month
AttributesDay of Year
Decade
Year
Month of Year
Variables
HierarchiesConcept-VariableName: Drill down path is Concept, VariableName,
VariableCode. Concept is from Bora Bora's hydrotagger
Medium-VariableName: Drill down path is Medium, VariableName,
VariableCode. Medium is the medium that the observation was taken in: air, water, soil, etc.
Units-VariableName Drill down path is Units, VariableName, VariableCode. Units are the units used in the observation ie (watts/m
2)
Method
This is a many to many dimension because some observations can have multiple methods associated with it.
HierarchiesMethodSource-Code: Drill down path is Method Source, MethodCode
MethodSource-MethodName: Drill down path is Method Source, MethodName
AttributesCitationName: ???
MethodSource: ASTM, ISO, STDMETH, USEPA, USGS
MethodCode: Code
MethodName: Description of the method