US Army Corps of Engineers
Hydrologic Engineering Center

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Water Quality

Water Quality Modules

Several water quality modules were developed to support a variety of H&H models and enhance their capabilities in terms of performing water quality analysis. The water quality modules include the water temperature simulation module, general constituent simulation module (GCSM), and nutrient simulation modules (NSMI and NSMII). NSMI simulates aquatic algae, nutrient cycles, DO, CBOD with simplified processes and minimum state variables. NSMII includes 24 water quality state variables associated with algae (phytoplankton), benthic algae, nitrogen cycle, phosphorous cycle, carbon cycle, silica cycle, sulfides, methane, DO, CBOD, alkalinity and pathogen. In addition, NSMII simulates algae, nitrogen, phosphorous and carbon cycles, and DO dynamics in more detail than NSMI. Both NSMI and NSMII have an option for computing dynamic sediment oxygen demand and sediment releases of nutrients using a sediment diagenesis module. The sediment diagenesis module is a separate component that is dynamically coupled with NSMI and NSMII.

Four water quality modules (Temperature, GCSM, NSMI, NSMII) are developed as Dynamic Linked Libraries (DLL’s) and are distributed as Temperature.dll, GCSM.dll, NSMI.dll, and NSMII.dll. These modules have been integrated into a variety of H&H models at various levels.

Nutrient Simulation Module I (NSMI):

Nutrient Simulation Module II (NSMII):

Sediment Diagenesis Sub-Module:

Dr. Todd Steissberg

Last Updated: 02/13/2020