National Water Quality System (NWIS) QWDATA Rounding Code/update to fix errors

In Reply Refer To:
Mail Stop 412
          November 14, 2001



OFFICE OF WATER QUALITY TECHNICAL MEMORANDUM 2002.03



Subject:  National Water Quality System (NWIS) QWDATA Rounding Code/update
to fix errors



A script has been written to update the NWIS QWDATA 'user rounding code'
for several hundred parameter codes.  The 'user rounding code' (has been
called the precision code) is the integer stored with each result in the
database that defines the number of decimal places or significant figures
when a user selects the 'user rounding' option for output.


The update will repair problems that were introduced into the 'user
rounding code' from several sources, including:

   1.  A nationally distributed NWIS field form that inserted a user
   rounding code of '4' for many field parameters.

   2.  A bug in the code that inserted a 'user rounding code' of '3'
   instead of referencing the parameter code dictionary.


The repair is limited to 'field' data and does not address problems in
rounding codes for analytical results.  The parameter code dictionary is
the source for the modifications, so the approach to this repair assumes
that one rounding array will work for each constituent.  Generally, the
parameter codes addressed in the script are:

   1.  Fixed value parameter codes

   2.  Field parameters (typically have a reporting order number less than
60)

   3.  Bacteria parameters

   4.  Field alkalinity and ANC parameters

   5.  Sediment concentration parameters

Detailed instructions for applying this update are located at:

http://ok.water.usgs.gov/nawqa/phoenix/rnd/upt_resultrnd.html


Questions can be emailed to phoenix@usgs.gov



                                              Stephen K. Sorenson /s/
                                              Acting Chief, Office of Water
                    Quality


This memorandum does not supersede any other Office of Water Quality
Technical Memorandum.


Distribution:  All WRD Employees


(See attached file: tech0203.rounding.fix.htm)



***********************************
Stephen K. Sorenson
Acting Chief, Office of Water Quality
US Geological Survey
412 National Center
Reston, Virginia 20192
703/648-6864
sorenson@usgs.go