Distribution of Earth’s Water• Earth is 70% Water!• 97 % of Earth’s Water is Salt Water.• Salt water is salty because it contains minerals and salts from weathered rocks and from underwater volcanoes.• 2 % of the Freshwater is frozen as ice near the North and South Poles• That only leaves about 1% of the planet’s water available for consumption for all living creatures!
Section 12-2Surface Water
Surface Water•Rivers, lakes, streams, ponds, andwetlands are all examples of surfacewater.
Types of WetlandsA wetland is a low-lying landarea where the soil is saturatedwith moisture eitherpermanently or seasonally.1. Marshes-shallow water withtall grasses. Freshwatermarshes form near ponds andlakes. Saltwater marshes arefound on the edges ofestuaries; places where a riverflows into the ocean.2. Swamps- low-lying areaswhich look like flooded forests.Located in warm, humidclimates where trees growquickly.
3. Bogs- Bogs begin as shallow ponds or lakes that slowlyfill with leaves and plants. Bogs are often in northern regionsand formed from old glacial lakes.•Because water does not flow in and out of a bog easily, theyoften have low oxygen. As a result, dead plants at thebottom of a bog do not break down but turn into Peat –anorganic material that forms when dead plants arecompressed.•This layer of peat can be up to forty feet deep! Peat makesthe bog acidic. Under the right conditions, this peat can turninto coal. The surface of a bog is often covered by a thicklayer of Sphagnum or “Peat Moss.”•Bog plants are well adapted to the high acidity, low oxygen,low nutrient supplies found in bogs.
Fun Facts About Bogs•Cranberry vines grow really well inbogs. To help harvest thecranberries, farmers flood the bog.
Fun Facts About Bogs• •Bogs have Carnivorous Plants!!! Note: Carnivorous Plants still photosynthesize, but “eat” insects to obtain nitrogen, since it is low in bog soil.
The Everglades: A Wetland •Water is the key to the Everglades, a unique region with both marshes and swamps. •The Everglades is a shallow stream of water that moves slowly over the land from Lake Okeechobee south to Florida Bay.
Role of Wetlands1. Wetlands provide habitats for many living things.2. Wetlands act like kidneys, naturally filtering water which can then be used by communities.3. Wetlands help control floods by acting like sponges, absorbing extra runoff from heavy rains. They store the water and slowly release it back into streams, lakes, and groundwater.4. Wetlands provide water during a drought.
What is Significant About This Article?Brian Handwerk http://www.cbsnews.com/vfor National Geographic News ideo/watch/?February 9, 2005 id=6773554n&tag=mncol;l st;2“Louisianas wetlands are being destroyed—an area the size of a football field disappears every 38 minutes.”"With the rapidly depleting wetlands, people that have lived in southern Louisiana can tell that, over the last 30 years, large storms now come in faster, and the water rises faster, which gives less time to respond and less time to evacuate," said Denise Reed, a professor of geology and geophysics at the University of New Orleans."In the next few years its going to get worse."
Why Must We Preserve and Protect Wetlands?•Example: In the last 70years, over 2,000 squaremiles of Louisianawetlands have beendestroyed.•Wetlands are oftendrained and filled in andused for agriculture ordevelopment.(In Louisiana an additionalproblem is the leveesystem designed toprevent flooding – it blocksnutrients and sedimentsfrom entering the wetlandsso they eventually Leveesdisintegrate)
Why Must We Preserve and Protect Wetlands?•Wetlands act asbuffers againsthurricanes becausethey slow down thestorm, lessening itsimpact.•Hurricane Katrinawould have likelybeen much lessdevastating to NewOrleans if thewetlands would nothave beendestroyed!
Why Must We Preserve and Protect Wetlands?•Engineers and scientists are nowtrying to create artificial wetlands toreplace ones that have been destroyed.
Section 12-3:Ground Water
How Water Moves Underground•Groundwater-Water that moves and fills spacesunderground.•Water underground trickles down between particles ofsoil and through cracks and spaces in layers of rock.Rock with connected pore space is considered to bepermeable rock.•Ex. Sandstone
How Water Moves Underground•As water soaks down through permeable rock and soil, iteventually reaches impermeable layers of material that it cannotpass through, for example clay.•When the rock reaches this layer, it begins to fill up the rockspaces above it.
How Water Moves Underground•The area of permeable rock that is totally filledwith water is called the saturated zone. The topof the saturated zone is the water table.
How Water Moves Underground•The layer of rocks and soil above the water table iscalled the unsaturated zone.•Any underground layer of rock that has water in it(including the saturated zone) is called an aquifer.
Groundwater•Groundwater, like surface water, movesdownhill toward rivers or the ocean.
Bringing Up Groundwater•People can obtain groundwater from an aquifer bydrilling a well below the water table.•They may also obtain water through by digging anartesian well. When rock above an aquifer is punctured,the release of pressure causes the water to rise up onits own!!
“Fiji Water” is from an Artesian Well
Fiji’s bottling facility built right on top of the artesian well
Shaler Water…•While most of the Pittsburgh area draws its drinking waterfrom one of the three rivers, Shaler’s water is actuallyground water that comes from 14 wells located along thebanks of the Allegheny River.•This underground aquifer (45 feet beneath the surface)originates beneath the Great Lakes and travels to WesternPA, beneath our rivers. Although not a real river, is oftenreferred to as “Pittsburgh’s underground river”.•The fountain at Point State Park draws water from thisaquifer too!
Springs and Geysers•Sometimes, ground water comes to thesurface naturally.•When the water table is at the earth’ssurface, a spring forms.• Spring water passes through the porespaces in rock and soil which naturally filterharmful substances out of the water.•Hot springs and geysers form when heatedground water comes to the surface.•What heats the groundwater? MAGMA!•What is the difference between geysers andhot springs?•Geysers occur when pressure builds up asheated water rises. When pressure isreleased, they erupt!•Hot springs form when hot water easilymakes its way to the earth’s surface.
Section 12-4 UsingFreshwater Resources
Uses of Water Interpreting Data: Which of the categories of water use shown in the graph represents the largest use of water in the United States? Agriculture.
Water Pollution – Point Source•A type of pollution thatcomes from a specificsource is considered pointsource pollution.•Ex. Factories like oilrefineries or sewagetreatment plants (combinedsewer overflow!) arecommon sources pointsource pollution.•Clean Water Act-mustobtain a permit beforedumping wastes or treatwastes prior to dumping intoa body of water.
Water Pollution – Non-Point SourceReview: What is runoff?• Water that does not soak into the ground and runs along the earth’s surface.
Water Pollution – Non-Point Source•When the point of origincannot be identified, it isconsidered Non-PointSource pollution.•Runoff absorbs what everit comes into contact withas it moves- pollution fromnearby construction, lawnchemicals, oil, grease,gasoline, salt residues fromroad de-icing, andespecially animal waste(and fertilizer) from farms.
I Only Drain Rain!•Never pour pollutants like paint ormotor oil down any kind of drain!
What Can You Do to Reduce Water Pollution?•Avoid usingpesticides andlawn fertilizers.•Instead of pavingyour driveway, usegravel.•Plant things!Trees, grass andother plants helpabsorb water andreduce runoff!
What Af fects the Amount of Water Available for Use? • Pollution • Overuse • Drought
Section 12-5See 12-5 Review and Reinforce Worksheet