The local settling rate of algae represents the net removal of algae due to settling. The user defines the local settling rate of algae at 20C. The settling rate is adjusted to the local water temperature using the relationship:
7:3.1.18
where is the local settling rate of algae (m/day or m/hr), is the local algal settling rate at 20C (m/day or m/hr), and is the average water temperature for the day or hour (C).
Table 7:3-1: SWAT+ input variables used in algae calculations.
Variable Name | Definition | File Name |
---|---|---|
AI0
: Ratio of chlorophyll a to algal biomass ( chla/mg alg)
.wwq
IGROPT
Algal specific growth rate option
.wwq
MUMAX
: Maximum specific algal growth rate (day)
.wwq
K_L
: Half-saturation coefficient for light (MJ/m-hr)
.wwq
TFACT
: Fraction of solar radiation that is photosynthetically active
.wwq
LAMBDA0
: Non-algal portion of the light extinction coefficient (m)
.wwq
LAMBDA1
: Linear algal self shading coefficient (m (-chla/L))
.wwq
LAMBDA2
: Nonlinear algal self shading coefficient (m(-chla/L))
.wwq
K_N
: Michaelis-Menton half-saturation constant for nitrogen (mg N/L)
.wwq
K_P
: Michaelis-Menton half-saturation constant for phosphorus (mg P/L)
.wwq
RHOQ
: Local algal respiration rate at 20C (day)
.wwq
RS1
: Local algal settling rate at 20C (m/day)
.swq