Lecture 2 - Environmental Systems

Question 1

eutrophication

Answer 1

excessive nutrient enrichment

Question 2

causes of algal blooms

Answer 2

eutrophication and warmer temperatures

Question 3

how does deforestation lead to drought

Answer 3

decreased water retention from roots, decreased shade from trees, underbrush also means less water retention

Question 4

system

Answer 4

• a collection of things/elements (matter or energy) that have a relationship (linkages/couplings - cause and effect relationship, exchange of matter or energy) and a defined boundary (where system ends, often arbitrary)
• a set of components that function together to act as a whole

Question 5

closed system

Answer 5

energy flows in and out, but material is not exchanged

Question 6

isolated system

Answer 6

neither energy nor material flows in or out

Question 7

continuity equation

Answer 7

relates inputs and outputs to the change in reservoir size

ΔS/Δt = Fi - F0 where S = reservoir size, Fi = input, and F0 = output

Question 8

2 possible states of a system

Answer 8

• steady state ΔS/Δt = Fi - F0 = 0 … so Fi = F0

- transient state ΔS/Δt = Fi - F0 ≠ 0 … so Fi ≠ F0

Question 9

complexity

Answer 9

the degree to which…

• a system’s design is difficult to understand or model
• components are interconnected
• many simply interacting parts collectively produce unexpected behavior

Question 10

residence time

Answer 10

average length of time a substance remains in a reservoir at a steady rate

reservoir volume/flow rate
reservoir volume/Fi or F0