Model:QUAL2K

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QUAL2K

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Summary Contact Technical specs In/Output Process Testing Other Component info Also known as Model type Single Model part of larger framework Note on status model Date note status model Spatial dimensions 1D Spatial extent Watershed-Scale Model domain Terrestrial One-line model description A Modeling Framework for Simulating River and Stream Water Quality Extended model description QUAL2K (or Q2K) is a river and stream water quality model that is intended to represent a modernized version of the QUAL2E (or Q2E) model (Brown and Barnwell 1987). Q2K is similar to Q2E in the following respects: One dimensional. The channel is well-mixed vertically and laterally. Steady state hydraulics. Non-uniform, steady flow is simulated. Diurnal heat budget. The heat budget and temperature are simulated as a function of meteorology on a diurnal time scale. Diurnal water-quality kinetics. All water quality variables are simulated on a diurnal time scale. Heat and mass inputs. Point and non-point loads and abstractions are simulated. Keywords: biogeochemistry, water quality, Name Steve Chapra Type of contact Model developer Institute / Organization Tufts University, Civil and Environmental Engineering Dept. Postal address 1 200 College Avenue Postal address 2 Town / City Medford Postal code 02155 State Massachusetts Country United States Email address Steven.Chapra@tufts.edu Phone Fax Name Greg Pelletier Type of contact Model developer Institute / Organization Postal address 1 Postal address 2 Town / City Postal code State Country Email address Phone Fax Name Hua Tao Type of contact Model developer Institute / Organization Postal address 1 Postal address 2 Town / City Postal code State Country Email address Phone Fax Supported platforms Windows Other platform Programming language Fortran90 Other program language Visual Basic (VBA), Excel Code optimized Single Processor Multiple processors implemented Nr of distributed processors Nr of shared processors Start year development 1987 Does model development still take place? Yes If above answer is no, provide end year model development Code development status When did you indicate the 'code development status'? Model availability As code Source code availability (Or provide future intension) Through web repository Source web address http://www.epa.gov/athens/wwqtsc/html/qual2k.html Source csdms web address Program license type Other Program license type other NOT SURE Memory requirements -- Typical run time -- Describe input parameters Too many to mention here Input format Other input format Describe output parameters -- Output format Other output format Pre-processing software needed? No Describe pre-processing software Post-processing software needed? No Describe post-processing software Visualization software needed? No If above answer is yes Other visualization software Describe processes represented by the model The QUAL2K framework includes the following new elements: Software Environment and Interface. Q2K is implemented within the Microsoft Windows environment. Numerical computations are programmed in Fortran 90. Excel is used as the graphical user interface. All interface operations are programmed in the Microsoft Office macro language: Visual Basic for Applications (VBA). Model segmentation. Q2E segments the system into river reaches comprised of equally spaced elements. Q2K also divides the system into reaches and elements. However, in contrast to Q2E, the element size for Q2K can vary from reach to reach. In addition, multiple loadings and withdrawals can be input to any element. Carbonaceous BOD speciation. Q2K uses two forms of carbonaceous BOD to represent organic carbon. These forms are a slowly oxidizing form (slow CBOD) and a rapidly oxidizing form (fast CBOD). Anoxia. Q2K accommodates anoxia by reducing oxidation reactions to zero at low oxygen levels. In addition, denitrification is modeled as a first-order reaction that becomes pronounced at low oxygen concentrations. Sediment-water interactions. Sediment-water fluxes of dissolved oxygen and nutrients can be simulated internally rather than being prescribed. That is, oxygen (SOD) and nutrient fluxes are simulated as a function of settling particulate organic matter, reactions within the sediments, and the concentrations of soluble forms in the overlying waters. Bottom algae. The model explicitly simulates attached bottom algae. These algae have variable stoichiometry. Light extinction. Light extinction is calculated as a function of algae, detritus and inorganic solids. pH. Both alkalinity and total inorganic carbon are simulated. The river’s pH is then computed based on these two quantities. Pathogens. A generic pathogen is simulated. Pathogen removal is determined as a function of temperature, light, and settling. Reach specific kinetic parameters. Q2K allows you to specify many of the *Weirs and waterfalls. The hydraulics of weirs as well as the effect of weirs and waterfalls on gas transfer are explicitly included. Describe key physical parameters and equations Too many to mention here. See manual. Describe length scale and resolution constraints -- Describe time scale and resolution constraints -- Describe any numerical limitations and issues -- Describe available calibration data sets Upload calibration data sets if available: Describe available test data sets Upload test data sets if available: Describe ideal data for testing Do you have current or future plans for collaborating with other researchers? -- Is there a manual available? Yes Upload manual if available: Media:Q2KDocv2 11b8.pdf Model website if any http://www.epa.gov/athens/wwqtsc/html/qual2k.html Model forum / discussion board Comments Questionnaire is filled out by Albert Kettner This part will be filled out by CSDMS staff OpenMI compliant No but possible BMI compliant No but possible WMT component No but possible PyMT component Is this a data component Can be coupled with:

Model info Authors Steve Chapra Pelletier, Tao Source code Go to external source code site Model citations Nr. of publications: 132 Total citations: 1760 h-index: 20 m-quotient: 0.83 QR-code Link to this page Other models by author QUAL2K

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Nr. of publications:	132
Total citations:	1760
h-index:	20
m-quotient:	0.83

Featured publication(s)	Year	Model described	Type of Reference	Citations
Chapra, S.C.; Pelletier, G.J.; Tao, H.; 2008. QUAL2K: A Modeling Framework for Simulating River and Stream Water Quality, Version 2.11: Documentation and Users Manual. . (View/edit entry)	2008	QUAL2K	Model overview	0
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