Skip to main content
ARS Home » Pacific West Area » Corvallis, Oregon » Forage Seed and Cereal Research Unit » Research » Publications at this Location » Publication #299751

Title: Improved stream temperature simulations within SWAT using NSGA-II for automatic, multi-site calibration

Author
item Barnhart, Bradley
item Whittaker, Gerald
item FICKLIN, DARREN - Indiana University

Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/28/2014
Publication Date: 4/30/2014
Citation: Barnhart, B.L., Whittaker, G.W., Ficklin, D.L. 2014. Improved stream temperature simulations within SWAT using NSGA-II for automatic, multi-site calibration. Transactions of the ASABE. 57(2):517-530.

Interpretive Summary: Stream temperature is one of the most influential parameters impacting the survival, growth rates, distribution, and migration patterns of many aquatic organisms. Distributed stream temperature models are crucial for providing insights into variations of stream temperature for regions and time periods where data does not exist. This study utilizes a relatively new stream temperature model incorporated into the well-known Soil and Water Assessment Tool (SWAT) in order to simulate stream temperatures at five sites on the Calapooia River, in northwest Oregon. An automatic calibration method is used to simultaneously fit the model to data at five sites. The results show that the new, integrated SWAT-temperature model can be calibrated to provide accurate simulations of environmental effects of agriculture practice that include water temperature.

Technical Abstract: Stream temperature is one of the most influential parameters impacting the survival, growth rates, distribution, and migration patterns of many aquatic organisms. Distributed stream temperature models are crucial for providing insights into variations of stream temperature for regions and time periods for which observed in-situ data does not exist. This study utilizes a relatively new stream temperature model incorporated into the well-known Soil and Water Assessment Tool (SWAT) in order to simulate stream temperatures at five sites on the Calapooia River within the Calapooia basin, in northwest Oregon. A hybrid genetic algorithm utilizing the Nondominated Sorting Genetic Algorithm-II (NSGA-II) is used to calibrate flow at a single outlet and stream temperatures at five sites. Previous studies have used manual, basinwide stream temperature calibration using this model; however, this is the first demonstration of an automatic, subbasin-level calibration for stream temperature at multiple sites. The subbasin calibration is shown to better match observed data than the original SWAT temperature model as well as the new temperature model calibrated basinwide. In addition to providing improved stream temperature simulations for the Calapooia River, the demonstration of the subbasin-level automatic calibration technique extends the applicability of the model, especially for complex basins with large spatial variability of topography, landuse, and soil type.