Chapter 9: Properties and Used of Water

I. Water’s Importance, Availability and Renewal

Our liquid planet glows like a soft blue sapphire in the hard-edged darkness of space. There is nothing else like it in the solar system. It is because of water. John Todd

https://www.youtube.com/watch?v=Q54a4PCV9Ac

Why is water so important-lifeblood of ecosystemMany Properties Related to Polarity-Strong Hydrogen Bonding

This picture shows the size of a sphere that would contain all of Earth's water in comparison to the size of the Earth. The blue sphere sitting on the United States, reaching from about Salt Lake City, Utah to Topeka, Kansas, has a diameter of about 860 miles (about 1,385 kilometers) , with a volume of about 332,500,000 cubic miles (1,386,000,000 cubic kilometers). The sphere includes all the water in the oceans, seas, ice caps, lakes and rivers as well as groundwater, atmospheric water, and even the water in you, your dog, and your tomato plant.

II. The Global Water Supply

Potentially Renewable Resource Cycled like other matter-HYDOLOGIC CYCLE

II. Groundwater-Potentially Renewable!Aquifer: groundwater exists in the multitude of small

spaces found within permeable layers of rock and sediment.

Unconfined: water can flow in and outConfined: impermeable layer of rock or clay impedes

water flow to or from the aquiferWater Table: uppermost level of ground water;

dynamicGroundwater withdraw/mining: removal of water for

agriculture and municipal use.Wells-Cone of Depression: drilling to aquifer to tap

water supply; if overpumped can cause near by wells to go dry.

Recharge: water from precipitation can percolate through soil and replace water that has been withdrawn.

The Ogallala Aquifer was formed about 10 million years ago when water flowed onto the highly permeable sand and gravel of the plains from retreating glaciers and streams from the nearby Rocky Mountains. Because of climate change, changes due to erosion and the lack of glacial meltwater, today the Ogallala Aquifer is no longer being recharged by the Rockies.

III. Surface Water

Streams/ RiversHumans settled along major rivers for transport and fertile soilFloodplain: land area flooded when rivers overflow banks during snowmelt or heavy rain; deposit nutrient rich sediment. Watershed/Drainage Basin: The land area surrounding a river that drains into the river

Ponds/ Lakes Depressions (often

from glaciation or tectonic activity) that are filled by precipitation runoff that is not absorbed into ground water.

Wetlands/swamps/marshes /bogs: land area that is saturated with water, either permanently or seasonally, such that it takes on the characteristics of a distinct ecosystem

Vary because of differences in soils, topography, climate, hydrology, water chemistry, vegetation, and other factors.

Economic drivers because of their key role in fishing, hunting, agriculture and recreation.

IV. Atmospheric WaterEssential to global water distributionRainfall in many regions follows specific

patternsDrought causes loss of human life, livestock,

crops. Effects fire and soil erosion.Dust Bowl-1920s and ‘30sHuman activities increase risk of flooding

Impermeable surfaces due to soil baked by drought or urban / suburban pavement and building

V. Humans Alter Availability of WaterLevees: enlarged bank built up on each side of

a river to control flooding.Mississippi River has largest levee system on

world.No deposition by natural flood watersSediment carried downstream and settle where

river enters oceanPrevent flooding at one location by cause it

further downstream. Encourage development in floodplainsDikes: similar to levee; prevent ocean water from

flooding land

http://www.youtube.com/watch?v=WbrjRKB586s

DamBarrier that runs across a river to control

water flow/generate electricity.A river valley is flooded creating a reservoir. Controversial Three Gorges Dam on Yangtze

River in ChinaFish ladders allow fish to get around dam and

continue migration.http://www.history.com/topics/hoover-dam/vide

os/the-hoover-dam

Fig. 14-13, p. 317

Aqueducts: canals or ditches to transport waterOlder aqueducts lost much water through leaks

and evaporation. New ones made of concrete and steel pipes above or below ground.

New York and LA rely heavily on aqeducts for water needs.

Problems: water diversion impacts natural river ecosystem. Conflict over who should get the water Aral Sea case study

Desalinization: Distillation and Reverse Osmosishttp://www.youtube.com/watch?v=qZ5ut_4zKug

VI: The Global Water Supply-How water is used

-We withdraw more water now than ever-5 fold increase since 1950-US has highest per capita use-Globally: 70% to irrigate agricultural land/20% industry/10% domestic/household use

Fig. 13-4, p. 322

Fig. 13-6, p. 323

Agriculture Ag output has kept up with irrigation because of large inputs-mostly water . India, China, US, Pakistan account for more than half the irrigated land in the world.

1. Drip irrigation2. irrigate at night3. Monitor moisture with computer sensor4. Line canals that transport water5. Grow water efficient/drought tolerant crops6. Hydroponics

Modern Marvels

IndustryGenerating electricity, cooling machinery, refining metals, manufacturing goods Households Toilet flushing biggest user!1. Water saving toilet, shower head, washer/water-less composting toilets2. Re-use gray water3. Increase Price/ Full cost pricing / Remove subsidies4. Fix water leaks

III. Too Little Fresh WaterEmerging Water ShortagesReasons For ShortagesDry climateDroughtToo Many PeopleWasteLack of money to drill deep wells and water distribution systems

http://news.bbc.co.uk/hi/english/static/in_depth/world/2000/world_water_crisis/default.stm

http://ngm.nationalgeographic.com/2010/04/water-slaves/rosenberg-text

http://www.cbsnews.com/video/watch/?id=5362301n

Kenya PicsNational Geographic-The Burden of Thirsthttp://www.youtube.com/watch?v=Q54a4PCV9Ac

http://ngm.nationalgeographic.com/2010/04/water-slaves/rosenberg-text

http://www.npr.org/2014/05/06/309101579/drought-stricken-texas-town-turns-to-toilets-for-water