Edit watershed level water quality parameters
What is it?
SWAT is able to model in-stream water quality process for nutrients, organic chemicals, heavy metals, bacteria and sediments. The process parameters are stored in stream water quality input file (.swq) for specific reaches and general water quality input file (.wwq). This interface is for editing water quality parameters for the entire watershed.How to use it:
SWAT uses enhanced stream water quality model QUAL2E for in-stream processes. For the detailed description of the processes and parameters, please refer to the SWAT Theoretical Documentation and SWAT Input/Output Documentation.
Select appropriate values for the each parameter described below.
LAO
Select desired light averaging option (LAO) for QUAL2E.IGROPT
Select appropriate algal specific growth rate option for QUAL2E.AI0: Ratio of chlorophyll-a to algal biomass (μg-chla/mg algae).
AI1: Fraction of algal biomass that is nitrogen (mg N/mg algae).
AI2: Fraction of algal biomass that is phosphorus (mg P/mg algae).
AI3: The rate of oxygen production per unit of algal photosynthesis (mg O2/mg algae).
AI4: The rate of oxygen uptake per unit of algal respiration (mg O2/mg algae).
AI5: The rate of oxygen uptake per unit of NH3-N oxidation (mg O2/mg NH3-N.).
AI6: The rate of oxygen uptake per unit of NO2-N oxidation (mg O2/mg NO2-N.).
MUMAX: Maximum specific algal growth rate at 20°C (day-1).
RHOQ: Algal respiration rate at 20°C (day-1).
TFACT: Fraction of solar radiation computed in the temperature heat balance that is photosynthetically active.
K_L: Half-saturation coefficient for light (kJ/(m2.min)).
K_N: Michael-Menton half-saturation constant for nitrogen (mgN/L).
K_P: Michael-Menton half-saturation constant for phosphorus (mgP/L).
LAMBDA0: Non-algal portion of the light extinction coefficient (m-1).
LAMBDA1: Linear algal self-shading coefficient (m-1 (μg-chla/L)-1).
LAMBDA2: Non-algal portion of the light extinction coefficient (m-1 (μg-chla/L)-2/3).
P_N: Algal preference factor for ammonia.
CHLA-SUBCO: Regional adjustment on sub chla_a loading.
After making the changes, click 'Save Edits' and close the interface.
Don't forget to click 'Save Edits' butoon on the 'mgnSWAT Edit SWAT Data' interface.