1. 13
Water

2. Importance of Water Cooking & washing Agriculture Manufacturing Mining
Energy production
Waste disposal
Use of freshwater is increasing

3. ****Solid form that floats in its own liquid form ****
Properties of Water
Composed
2 Hydrogen and 1 oxygen
Exists as solid, liquid or gas
High heat capacity
Polar
Forms Hydrogen bonds between 2 water molecules
H-bonds define water’s physical properties
****Solid form that floats in its own liquid form ****

4. Properties of Water Water is never completely pure in nature
Universal Solvent
water dissolves many substances some of which cause water pollution
The most abundant compound on the earths surface
Water usually makes up
55% - 78% of the human body
Dihydrogen monoxide (DHMO)

5. Hydrologic Cycle
Water continuously circulates through he environment, from the ocean to the atm. to the land and then back to the ocean.

6. Distribution of Water Only 2.5% of water on earth is freshwater
2% of this in the form of ice
Only ~0.5% of water on earth is available freshwater

7. Freshwater Terminology
Surface water
Precipitation that remains on the surface and does not seep into soil
Runoff
Movement of surface water to lakes, rivers, etc.
Watershed (drainage basin)
Land area that delivers water into a stream or river system
Groundwater
Freshwater under the earth’s surface stored in aquifers
Aquifer
Underground caverns and porous layers of sand, gravel and rock in which groundwater is stored

8. Freshwater Aquifer
© 2012 John Wiley & Sons, Inc. All rights reserved.

9. Water Use & Resource Problems
Fall into Three Categories
Too much water  Flooding
Too little water
Poor quality/contamination
(addressed in Chapter 21)

10. Too Much Water Flooding Modern floods are highly destructive
Both natural & human-induced
Modern floods are highly destructive
We have removed water-absorbing plant cover
Humans construct buildings on floodplains
Floodplain
Area bordering a river channel that has the potential to flood

11. Pre-Urban vs. Urban Floodplains
© 2012 John Wiley & Sons, Inc. All rights reserved.

12. Floodplain Government restrictions on building
Levees can fail (We still continue to build on flood plains)
Rather than rebuild levees adjacent to rivers, experts suggest allowing some flooding of floodplains during floods
The effects of flooding are more destructive today than in the past because we continue buildings are constructed on flood plains.
Traditional levees adjacent to river
Suggested levee style, set back from river

13. Floods of Summer 2008 Mississippi Floods 2008
Was only one in a series of floods along the river.
States affected by the flooding included Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, and Wisconsin.
The flood left thirteen dead and damage region-wide was estimated to be in the tens of billions of dollars.
Why this happened
Several months of unusually heavy precipitation
levees that failed to hold back floodwaters draining wetlands
building on flood plains.

14. Too Little Water Typically found in arid land Problems Drought
Overdrawing water
for irrigation purposes
Aquifer depletion
Subsidence
Sinkholes
Saltwater Intrusion 

15. Water Problems In US and Canada
Overall, US has a plentiful supply of freshwater
Compared to other locations
Many areas do have a severe shortages
Geographical variations
Seasonal variations
So. Cal is a desert
Water in Southern CA.
Groundwater sources ( %)
Imported from Owens Valley, the Colorado River, and the State Water Project.

16. Water Problems In US and Canada
Water shortages in West and Southwest
Water is diverted and transported via aqueducts
© 2012 John Wiley & Sons, Inc. All rights reserved.

17. Water Problems in US & Canada Surface Water
Mono Lake (Eastern CA)
Rivers and streams that once fed this lake are diverted to Los Angeles (275mi away)
Becoming highly saline
Court ordered water diversion reduction
Colorado River Basin
Provides water for 27 million people
Numerous dams for Hydropower
Colorado River no longer reaches ocean

18. Colorado River bed in Mexico

19. Water Problems in US & Canada Groundwater
Aquifer Depletion

20. Water Problems in US and Canada- Groundwater
Ogallala Aquifer
High Plains
Largest groundwater deposit in world
Water withdrawn for agriculture faster than nature replaces it

21. Global Water Problems Freshwater on the planet CAN meet human needs
BUT, it is unevenly distributed
Some places lack stable runoff
Part of precipitation run off that an area gets ever month
Problems:
Weather & Climate
Drinking Water
Population Growth
Sharing Water Resources Among Countries

22. Global Water Problems Water & Climate Drinking Water Problems
Climate change affects the type & distribution of precip.
Potential issues:
Reduced snowfall will impact water resources downstream
Sea level rise will cause saltwater intrusion into drinking water supplies
Drinking Water Problems
Many developing countries have insufficient water to meet drinking and household needs
1.1 billion people lack access to safe drinking water

23. Global Water Problems Population Growth
Increase in population means an increase in freshwater requirements
Limits drinking water available
Limits water available for agriculture (food)
Sharing Water Resources Among Countries
Rhine River Basin
Countries upstream discharged pollutants into river
Countries downstream had to pay to clean the water before they could drink it

24. Aral Sea - Uzbekistan Water diversion for irrigation has caused sea to become too saline
1976
2010

25. Water conflicts

26. Water Management Main Goal:
Provide sustainable supply of high-quality water
Dams and Reservoirs
Benefits:
Ensure year-round supply of water with regulated flow
Generate electricity
Provide recreational activities
Disadvantages
Alter the ecosystem
Reduce sediment load
Water Diversion Projects
Desalinization

27. Dams and Reservoirs Glen Canyon Dam
Powerful spring floods brought sediment, which created sandbar habitat
Regulated flow is detrimental to wildlife
To rectify this, government started flooding the Grand Canyon periodically starting in 1996

28. Dams and Reservoirs
Salmon population in Columbia River very low due to dams that impede migration
Fish ladders help, but are not effective enough

29. Water Diversion Projects
Water diverted to areas that are deficient
Much of Southern CA receives its water supply from diverted water from Northern CA
Controversial and expensive

30. Desalinization Removal of salt from ocean or brackish water
Two methods: (Very expensive)
Distillation
salt water is evaporated & water vapor is condensed into freshwater
Reverse Osmosis
involves forcing salt water through a semi-permeable membrane (permeable to water, but not salt)
Very large industry in Saudi Arabia

31. Water Conservation Reducing Agricultural Water Waste
Agriculture is very inefficient with water
Microirrigation - irrigation that conserves waster by piping to crops through sealed systems
(AKA drip or trickle irrigation)
Reducing Industrial Water Waste
Stricter laws provide incentive to conserve water
Water scarcity encourages further industrial recycling
Potential to conserve water is huge

32. Water Conservation Reducing Municipal Water Waste Gray Water
Non-potable water
Water that has already been used one time
Can be used to flush toilets, wash car or water lawn
Water saving household fi appliances
Government incentives

33. Conserving at Home Install water-saving shower heads and faucets
Install low-flush toilets
Fix leaky fixtures
Purchase high efficiency fixtures
Modify personal habits
Use the dishwasher instead of washing by hand
Yup it uses less water
Gov. is providing cash incentives to help individuals