Water: A Limited Resource

1
Water A Limited Resource
Chapter 14
2
The Importance of Water

• Water
• shapes continents
• moderates our climate
• is essential for all living organisms

3
The Importance of Water

• Properties of Water

4
The Importance of Water

• Properties of Water

Chemical composition of seawater
5
The Importance of Water

• The Hydrologic Cycle

6
The Importance of Water

• Our Supply of Fresh Water

7
The Importance of Water

• Types of water
• surface water
• runoff
• drainage basin
• groundwater
• aquifers

8
The Importance of Water

• Largest watersheds

9
The Importance of Water

• Aquifers

10
Water Use and Resource Problems

• Problems fall into 3 categories
• Too much
• Too little
• Poor quality / contamination (Chap. 22)

11
Water Use and Resource Problems

• Too Much Water
• Removing vegetation and constructing buildings
  increases flooding potential on flood plains

12
Water Use and Resource Problems

• Too Much Water
• Flood Management

13
Water Use and Resource Problems

• Too Much Water
• Flood Management

Levees with natural river
14
Water Use and Resource Problems

• Case-in-Point The Floods of 1993

15
Water Use and Resource Problems

• Too Little Water
• Droughts
• Overdrawing Surface Waters
• Aquifer depletion
• Causes subsidence
• Can lead to saltwater intrusion

16
Water Use and Resource Problems

• Saltwater intrusion

17
Water Use and Resource Problems

• Too Little Water
• Droughts
• Overdrawing Surface Waters
• Aquifer depletion
• Causes subsidence
• Can lead to saltwater intrusion
• Salinization of Irrigated Soil

18

• Average annual precipitation

19
Water Problems in the US

• Surface Water
• Most problems in the West and Southwest
• Aqueducts transport water from distance sources

20
Water Problems in the US
Surface Water

• Examples of problems
• Mono Lake
• The Colorado River
• Basin

21
Water Problems in the US

• Groundwater
• Aquifer depletion

22
Water Problems in the US

• Groundwater
• Aquifer depletion
• - Ogallala Aquifer

23
Global Water Problems

• Water distribution globally is very inequitable
• In addition, stable runoff varies
• Drinking Water Problems
• 1.4 billion lack safe water
• 2.9 billion lack proper wastewater disposal

24
Global Water Problems

• Population Growth and Water Problems
• India 8,000 villages have no local water
• China water table falling 2-3 m / year
• Pakistan lack of water led to riots in 2001
• Mexico water table falling 3.5 m / year in
  Mexico City

25
Global Water Problems

• Sharing Water Resources among Countries

26
Global Water Problems

• Sharing Water Resources among Countries

The Aral Sea
1976
27
Global Water Problems
Sharing Water Resources among Countries

• Potentially Volatile International Water
  Situations
• Jordan River
• Nile River

28
Water Management

• Providing a Sustainable Water Supply
• Sustainable water use seeks to provide water to
  future generations without damaging ecosystems.

29
Water Management

• Providing a Sustainable Water Supply
• Dams and Reservoirs

• Pros
• Ensure year-round water supply
• Hydropower
• Recreation

30
Water Management

• Providing a Sustainable Water Supply
• Dams and Reservoirs

• Cons
• Alter ecosystems
• Sediment Deposition

31
Water Management

• Providing a Sustainable Water Supply
• Dams and Reservoirs
• Example Effect of dam on Colorado River in
  Grand Canyon

32
Water Management

• Providing a Sustainable Water Supply
• Water Diversion Projects

33
Water Management

• Providing a Sustainable Water Supply
• Desalinization

Two methods 1) Distillation
34
Water Management

• Providing a Sustainable Water Supply
• Desalinization

Two methods 1) Distillation 2) Reverse osmosis
Salt impermeable membrane
Salt water
Fresh water
35
Water Conservation

• Reducing Agricultural Water Waste

36
Water Conservation

• Reducing Agricultural Water Waste
• Reducing Water Waste in Industry

Reducing Municipal Water Waste