* Chemical analysis performed by a qualified laboratory
* Not being previously archived in STORET
* Samples taken from streams
* Sampling sites with enough location information to be tied to a specific stream location
* Water chemistry data containing at least one parameter for Nitrogen or Phosphorus
This data was then formatted into a relational data model by the StreamNet project and was georeferenced to precise stream-based locations. This resulting data set is a point GIS layer of the stream-based locations where the sites exist and related tables which contain water quality sample data from these locations. Approximately 65% of the stream sampling sites in the original PSMFC streams water quality data compilation were georeferenced to create these GIS coverages. The remaining 35% were not included because they could not be linked to a specific stream-based location with confidence. Each stream-based location in the source PSMFC data set had a latitude and longitude and a stream name but the lat/long values were not always reliable. A stream-based site was included in this data set if the following criteria were met:
* The longitude/latitude point from the source PSMFC data set was within 400 feet of a stream in the PNW Reach files (1:100,000 hydrography)
and
* The name of that stream in the 1:100,000 layer matched the stream name for the sampling site in the source data set.
If these two criterion were met, then an automated GIS procedure was used to snap the longitude/latitude point to the stream-based location in the 1:100,000 scale hydrography.
Sites where this criteria was not met were not included in this final data set. References are documented with the RefID field for each data record in the WQLake_Data table. Each RefID relates to the source reference of the data which is kept in hardcopy at the StreamNet library.
For questions about the dataset, please use the following contacts:
Any questions concerning the original PSMFC data compilation can be directed to
Erik Hanson Pacific States Marine Fisheries Commission 45 SE 82nd Drive Suite 100 Gladstone, OR 97027 (503) 650-5400 erik_hanson@psmfc.org
Any questions about the georeferencing of this data or this GIS data file can be addressed to:
Travis Butcher Pacific States Marine Fisheries Commission StreamNet Project 45 SE 82nd Drive Suite 100 Gladstone, OR 97027 (503) 650-5400 travis_butcher@psmfc.org
Any background information, reports, or data can be found at:
StreamNet Library Columbia River Inter-Tribal Fish Commission Ste. 190, 729 NE Oregon St. Portland, OR. 97232-2107 (503) 731-1304 www.streamnet.org/library.html
Dataset structure:
This database contains a number of related tables, both spatial and tabular:
WQ_StreamSites (spatial) - The point locations of the stream-based sampling sites. Each location has an LLID (unique stream identifier) and a BegFt (feet measurement on the stream route) which pinpoints the site location. Each site relates to the water quality sampling data in the WQ_StreamData table (tabular) through the StreamSiteID field (one to many relationship).
WQ_StreamData (tabular) - Contains actual water quality measurements (one record per measurement) at taken at the stream sites. Relates to the WQ_StreamSites GIS layer through the StreamSiteID field (many to one relationship).
WQ_Parameters - Describes the water quality parameters that were sampled for. Relates to the WQ_StreamData table on the ParamID attribute (one to many relationship)
WQ_Flag (tabular) - Describes flags which were given to some of the data samples. Relates to the WQ_StreamData table on the Flag attribute (one to many relationship).
WQ_Reference (tabular) Contains information about the source documents for these water quality records. Relates to the WQ_StreamData table on the RefID attribute (one to many relationship)
** NOTE: Tabular data is included with this data set both as single MS Access 97 database and as individual text files to serve the needs of various users. Additional attribute information for this tabular data is contained in the WQ_tabularformat.doc which is also included.