1. Neuse Estuary Eutrophication Model

3. Cause and Effect Relationships NeuBERN Bayes Net Estuary Model
Nitrogen
Inputs
Cause and Effect
Relationships
River
Flow
Algal
Density
Chlorophyll
Violations
Carbon
Production
Sediment
Oxygen
Demand
Harmful
Algal Blooms
Frequency
of Hypoxia
Duration of
Stratification
NeuBERN
Bayes Net
Estuary Model
Number of
Fishkills
Fish
Health
Shellfish
Abundance

6. Model proposed by Chen and Orlob (1972)

7. Phytoplankton (Algae) Mass Balance
(equation from the model proposed by Chen and Orlob (1972))
where:
V = segment volume (m3)
C1 = phytoplankton concentration (g/m3)
Q = flow volume (m3/t)
E = diffusion coefficient (m2/t)
A = segment surface/bottom area (m2)
µ1 = phytoplankton growth rate (t-1)
R1 = phytoplankton respiration rate (t-1)
s1 = phytoplankton settling rate (t-1)
M1 = phytoplankton mortality rate (t-1)
µ2 = zooplankton growth rate (t-1)
C2 = zooplankton concentration (g/m3)
F2,1 = fractional feeding preference

8. (Chapra and Reckhow 1983, Chapter 14)
Parameter Selection Example: Phytoplankton Settling
For phytoplankton settling, another common approach is to treat phytoplankton settling as a velocity term with an areal loss:
(Chapra and Reckhow 1983, Chapter 14)
phytoplankton settling (mass/time) = v1AC1

9. Table 1. Phytoplankton settling velocities (Bowie et al. 1985)