Water & Energy

Question 1

Water flow

Answer 1

Evaporation = 423 x 10^3 km3/yr
(62 x 10^3 km3/yr from land)

Precipitation = 423 x 10^3 km3/yr
(99 x 10^3 km3/yr onto land)

Run Off = Precipitation - Evaporation
= 37 x 10^3 km3/yr

Only about 10 x 10^3 km3/yr usable water
(up from ~7 x 10^3 km3/yr in 1900 due to the use of dams and diversions)

Question 2

Groundwater

Answer 2

Run off percolates through soils to aquifers to replenish used groundwater, and this allows some groundwater to be contaminated

Question 3

Fossil water

Answer 3

Aquifers that are not replenished once used

Question 4

Point and non point sources of contamination

Answer 4

Point: linked to a specific location such as a landfill

Non point: widespread and much more difficult to trace and contain such as fertilizers

Question 5

2 extraordinary properties of water

Answer 5

1) Ice floats as a solid

2) Water is most dense at 4 degrees

Question 6

Eutrophication and its ecology impacts

Answer 6

Natural biological process producing sediments after an increased period of algal growth when algae die and sink, decomposition uses O2 to create anoxic water regions. This process accelerates due to excessive nutrient levels in the water like P and N (Lake Erie)

Ecological impacts: similar to early earth

1) Increase phytoplankton
2) Increase blooms of zooplankton
3) Decreased fish and shellfish biodiversity
4) Change in macrophyte species
5) Increased water turbidity and decreased sunlight penetration
6) Change in colour and smell of water

Question 7

Aquaculture

Answer 7

Aquatic farms

Problems:

1) Some species still depend on ocean fishing (for feed)
2) Waste in fish farms leads to eutrophication of local water
3) Overcrowding leads to infections and high use of antibiotics
4) Biotechnology “designer fish”
5) Sea lice

Question 8

Anaerobic vs Aerobic conditions

Answer 8

Anaerobic produces: NH3, CH4, H2S

Aerobic: NO2, CO2, SO2