Lecture 18: Global Water Poverty

Question 1

What is the water scarcity index?

Answer 1

Physical availability of renewable water on a percentage scale:

Renewable water = water withdrawn from all sources / discharge

Question 2

What is the water poverty index?

Answer 2

Physical availability of water: accounts for social, economic, and environmental factors

Question 3

How do we address the issues between water supply and demand?

Answer 3

• capturing runoff
• moving remote water
• “producing” more water

Question 4

How do we capture runoff water?

Answer 4

Dams & reservoirs (manmade structures designed to hold precipitation)

Question 5

How does capturing runoff negatively effect ecosystems?

Answer 5

• water flooding green spaces causes anaerobic decomposition (releasing lots of methane)
• displacing animal/human communities (usually poor indigenous communities)
• fish migration & mating patterns disrupted

Question 6

How is remote water moved?

Answer 6

Trucks/ships & pipelines

Question 7

What is required for pipelines to be feasible?

Answer 7

• longterm unavailability at the end
• longterm availability at the start
• enough energy to power the pumps
• political agreements between suppliers and consumers

Question 8

How do trucks/pipelines affect economic stability?

Answer 8

• cant hold down a job if you spend all day walking back and forth to water trucks
• usually children and women (interferes with education)

Question 9

How do we “make more” water?

Answer 9

• extract non-renewable sources
• recycle water
• desalinate water

Question 10

Why could extracting groundwater be bad?

Answer 10

refill over 100-1000 years (outside human lifespan)
also takes up physical space so removing groundwater causes land subsidence (decreased elevation)

Question 11

What are the levels of recycles water?

Answer 11

• treated water: contaminants removed to be potable
• grey water: nontoxic waste water from household sinks, baths, dishwashers
• reused water: water treated for certain uses (not human consumption)
• untreated/black water: untreated and contains toxic contaminants

Question 12

What is the “yuck” factor?

Answer 12

Difficulty in convincing populations that recycles waer is safe to drink

Question 13

What is desalination?

Answer 13

Removing salt to produce freshwater: feasible for communities located close to oceans/seas
limited by monetary and electrical cost, constant maintenance requirements, limited capacity, and hyper-concentrated salt solutions