2.5. Box Model for Flowing Systems

Try these first

1. 1.

   Define the 'box model' in environmental science.

   Hint

   Think about how a box model visualizes pollutants.

2. 2.

   What is a 'mass balance equation'?

   Hint

   Remember the formula discussed in class.

3. 3.

   What does the box model assume about pollutant concentration?

   • It varies throughout the water body
   • It remains constant in the designated volume
   • It is unpredictable

   Hint

   Consider the basic assumption of uniform mixing.

4. 4.

   True or False: In a steady-state, the concentration of pollutants varies with time.

   • True
   • False

   Hint

   Think about the definitions we've discussed.

5. 5.

   A river section has an inflow of 20 mg/L from a tributary and an outflow of 15 mg/L after a mixing distance. The concentration in the middle of the river section is measured. If the section's volume is not constant, how would you adjust your box model's assumptions for accurate predictions?

   Hint

   Think about how variable inflows affect local conditions.

6. 6.

   If a lake experiences a rise in pollutant concentration due to agricultural runoff, how do you apply the mass balance equations to predict future concentrations?

   Hint

   Observe how changing inflows could affect overall mass balance.