Water Resources Applications Software

Geochemical || Ground Water || Surface Water || Water Quality || General

Summary of SWPROD

       swprod - Determination of primary productivity and community
                metabolism in streams and lakes using diel oxygen

       The SWPROD program calculates daytime net productivity, night
       respiration, and total community metabolism from a diel series of
       dissolved oxygen, temperature, and salinity measurements.  An Odum
       approach is used for the solution of the oxygen-balance equation at
       a single station in a stream or as a difference between upstream and
       downstream stations.  Net oxygen production and subsequent community
       metabolism of horizontal lake segments are calculated assuming a
       one-dimensional model using a finite-difference equation.  The
       results are useful for general aquatic ecosystem characterization
       and as input to water-quality models for dissolved-oxygen analysis
       of aquatic environments. SWPROD is a revision of the USGS program

       Procedures for defining the diel oxygen relationship utilize
       dissolved-oxygen measurements to solve the basic oxygen equation.
       The applicability and accuracy of the procedures are limited by the
       assumptions.  Reaeration is assumed to be constant over the 24-hour
       period.  Advective transport must be absent or the quantity of
       oxygen so transported must be known.  No assumptions concerning
       daytime respiration are made; therefore, values for gross production
       are not calculated.  Any accrual or loss of water must be known.
       Turbulence must be low enough to permit observation of nighttime
       decline in dissolved oxygen.  There must be sufficient plant biomass
       present to provide a daytime increase in oxygen due to

       1991 - Printout modified to 80 columns.  The plot option was
          eliminated.  Additional printout added.

       1976 - Version J330, ran on IBM 360 or 370.

       Temperature, dissolved oxygen, and conductivity.

       Output consists of computed production and metabolism results and
       optional presentation of interpolated data.

       SWPROD is written in Fortran 77 with the following extension: use of
       include files.

       Stephens, D.W., and Jennings, M.E., 1976, Determination of Primary
          productivity and community metabolism in streams and lakes using
          diel oxygen measurements: U.S. Geological Survey Computer
          Contribution, 100 p.

       Bella, D.A., 1970, Dissolved oxygen variations in stratified lakes:
          American Society of Civil Engineers Journal of Sanitary
          Engineering, v. 96, no. SA-5, p. 1129-1146.

       Odum, H.T., 1956, Primary production in flowing waters:  Limnology
          and Oceanography, v. 1, no. 2, p. 102-117.

       Slack, K.V., Averett, R.C., Greeson, P.E., and Lipscomb, R.G., 1973,
          Methods for collection and analysis of aquatic biological and
          microbiological samples:  U.S. Geological Survey Techniques of
          Water-Resources Investigations, book 5, chap. A4, 165 p.

       Operation and Distribution:
          U.S. Geological Survey
          Hydrologic Analysis Software Support Program
          437 National Center
          Reston, VA 20192

       Official versions of U.S. Geological Survey water-resources analysis
       software are available for electronic retrieval via the World Wide
       Web (WWW) at:


       and via anonymous File Transfer Protocol (FTP) from:

         (path: /pub/software).

       The WWW page and anonymous FTP directory from which the SWPROD
       software can be retrieved are, respectively:


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