1. The Supplies The Product eutrophication: nutrient-driven stimulation of plant growth; contrast natural and cultural eutrophication; phosphorus is most often the limiting nutrient in freshwaters. CE5504. Lab 1 – Coupling Empirical and Mechanistic Models

2. Manifestations of eutrophication – algae and macrophytes

3. Manifestations of eutrophication - transparency Dodson 2005

4. Manifestations of eutrophication – oxygen depletion Temperature (°C) Depth (m) Spring Summer

5. Manifestations of eutrophication – oxygen depletion

6. mgO 2  L -1 A M J J A S

7. BUDGET MODEL for phosphorus W Q∙P v∙A s AsAs V

8. TROPHIC STATE CORRELATIONS – phosphorus and chlorophyll log total phosphorus (mgP  m -3 ) log chlorophyll (mg  m -3 ) 0 1 2 3 32 1 0 log Chl = 0.813  log TP-0.240 R 2 = 0.59 (b)

9. TROPHIC STATE CORRELATIONS – chlorophyll and Secchi disk Chlorophyll (mg  m -3 ) Secchi Disk Transparency (m) 2.55 10 25 50 0.5 2.0 3.0 1.0 log SD = -0.54  log Chl + 0.78 R 2 = 0.76 (a)

10. TROPHIC STATE CORRELATIONS – phosphorus and AHOD Areal Hypolimnetic Oxygen Demand (gO 2  m -2  d -1 ) Total Phosphorus (mgP  m -3 ) AHOD = 0.0145  TP + 0.47 R 2 = 0.79 (c)

11. ASSIGNMENT: Lab 1. Coupling Empirical and Mechanistic Models