Water-Quality Modeling Group

Science Center Objects

The USGS Oregon Water Science Center water-quality modeling group develops and uses models at a range of scales, from those that focus on a specific reservoir or river reach to large-scale nutrient models of the entire Pacific Northwest.

In the field of surface water, a water-quality model is a mathematical representation of a river, stream, lake, or reservoir. These models include equations and algorithms that describe the processes affecting temperature, dissolved oxygen, pH, alkalinity, nutrients, organic matter, toxics, aquatic plants, algae, and/or suspended sediment. Streamflow or circulation patterns are often a component of water-quality modeling, because mass transport is critical to water-quality cycles.

The USGS Oregon Water Science Center (ORWSC) water-quality modeling group develops and uses models at a range of scales, from those that focus on a specific reservoir or river reach to large-scale nutrient models of the entire Pacific Northwest.

Water-quality models have many applications and can be used to:

  • Identify controlling water-quality processes
  • Pinpoint data needs and target fieldwork
  • Estimate water quality in areas without monitoring data
  • Support TMDL analyses
  • Explore water-quality effects of management options, restoration, or environmental change

Models from one to three dimensions are used within the USGS Oregon Water Science Center. Modeling tools in use include CE-QUAL-W2 (W2)SPARROWPRMS, UnTRIM, RBM-10, HEC-RASSELDM, and various artificial neural network (ANN) and spreadsheet-based and custom models built with R and perl. Optimization of model parameter values sometimes utilizes the parameter estimation software PEST.

Water-quality modeling at ORWSC is conducted in cooperation with federal, state, and local agencies. Technical modeling assistance is also provided to others within USGS. Collaboration with biologists, resource managers, regulators and others interested in water quality has been a natural outgrowth of the modeling program.