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56 Cards in this Set
- Front
- Back
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Colorado River basin |
•7 states share the Colorado River •We didn't use to have large pop we have now, but now Las Vegas and LA are huge. Lots of people need water but agriculture is heavily dependent on the river for their water needs. •Arid area-very dry--almost total desert or close •If growing plants in those cities, need water from the river •Can't produce hydroelectric power in CA b/c reserves are so low. •Drought in CA, Mexico, and Central America •Drought caused by ridge of high pressure pushing storms north, making all these areas suffer •Droughts & overuse threatening supplies •Las Vegas, Nevada needs more water than allotted •Other states let Las Vegas drill for underground water. Great concerns so issue may end up in Nevada SC or SCOTUS •Drilling threatens areas ecology and people |
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The Colorado River |
•Originates in Rocky Mountains and drains into the Gulf of California. Probably can't reach anymore •Its water chiseled the Grand Canyon, but has been reduced to a mere trickle •Dams provide flood control, recreation, and hydroelectric power -30 million people use the water
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Dams |
Primary mission=flood control Hydroelectric power=bonus When lots of water, hold back so lower areas don't flood Have to let a certain amount of water through but also need to hold it back for hydroelectric power Lots controlling how operate those dams. If let too much through, can't generate power. Have to decide what goes through and what doesn't. |
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Freshwater systems |
Water may seem abundant, but drinkable water is rare. Limited resource with our population size. Our planet is all water, but 97.5% is ocean water and only 2.5% is freshwater Out of the freshwater, 79% is in ice caps and glaciers, 20% is groundwater, and 1% is surface freshwater. This 1% of freshwater is our water supply (rivers and lakes, anything you can put your foot in) |
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Freshwater |
Relatively pure, with few dissolved salts Most of it is tied up in glaciers, ice caps, and aquifers Surface freshwater--1% of freshwater: 52% is lakes, 38% soil moisture, 8% atmospheric vapor, 1% rivers, and 1% is water within organisms Some places depend on snowmelt for drinking water. If little snow, may not have a lot of drinking water that year If need glaciers for water supply, nervous b/c melting rapidly |
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Why don't we use desalination? |
Time consuming, expensive, energy intensive to pull all that salt out, and pulls out a lot of salt as a waste product |
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Hydrologic cycle |
Water evaporates over the oceans, moves inland, and comes down as rain, snow, etc. As water is cycled, it redistributes heat, erodes mountains, builds river deltas, and maintains ecosystems and organisms Also shapes civilizations and political conflicts |
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How water shapes civilizations and political conflicts |
Civilizations want to be built around water b/c can use it for agriculture and transportation Most civs have been based around water. Most major areas are along rivers or oceans. Before steam engine and such, used for transport b/c easier to carry things along it than use animals or something Historically, many wars fought over water rights. Human right. Important thing. If start running out of water, people will panic. |
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Surface water |
On Earth's surface 1% of freshwater |
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Runoff |
Water that flows over land Water merges in rivers and ends up in a lake or ocean |
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Tributary |
A smaller river flowing into a larger one |
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Watershed |
Drainage basin The area of land drained by a river system (river and its tributaries) |
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Rivers |
Shape the landscape Braided rivers Meandering rivers Water on the outside of rivers move faster and water on inside is deeper so moves slower. Sediments get deposited on inside. Rivers and steams host diverse ecological communities/have lots of species •Algae, insects, fish, amphibians, birds, etc. |
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Oxbow |
areas where river bends become exaggerated |
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Oxbow lakes |
Erosion cuts off and isolates an oxbow into a U-shaped water body When rivers start pushing in different directions and have huge, exaggerated bends, if there's a flood it'll change the course of the river w/ sediments cutting off the rest of the river. Get oxbow lakes Main channel of river separate from lake. Evolution-can have 2 different pops and species emerge. Diff species in lake than moving water b/c adapted to diff things. |
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Floodplain |
Areas nearest the river's course that are flooded periodically Areas expected to flood every so often Could have lots of water around it b/c of large amounts of rain Frequent deposition of silt makes floodplain soils fertile Good areas for agriculture. Most areas for agriculture are around a floodplain b/c there's lots of water, but also the soil has a lot of nutrients. When water slows down, releases lots of sediments. Flooded river comes out of its banks and that water is out of channel so slows down and lets lots of nutrients out into the soil. |
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Pros and cons of floodplains |
Create soil that's fertile and great for agriculture Build levies and ditches to limit flooding around agricultural land Not flooding, but then soil not being replenished and getting nutrients deposited, wear out soil over time. Important to have floods in the agricultural areas even though means floods sometimes. |
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Hundred year floodplains |
Some floodplains only flood every hundred years Would only expect flood once a century |
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Riparian |
riverside areas that are productive and species-rich |
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Lakes and ponds |
Ecologically diverse Bodies of open, standing water Vary in their nutrients and oxygen--ogliotrophic and eutrophic Eventually, water bodies fill completely through the process of succession Largest lakes known as inland seas: Great Lakes and the Caspian Sea |
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Littoral zone |
region ringing the edge of a water body rooted aquatic plants grow in this shallow part sunlight reaches the bottom and allows plants to grow |
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Benthic zone |
extends along the bottom of the water body home to many invertebrates |
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Limnetic zone |
open portion of the lake or pond where sunlight allows photosynthesis but doesn't reach the bottom |
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Profundal zone |
water that sunlight doesn't reach supports fewer animals b/c there's less oxygen bacteria and fungi |
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Ogliotrophic lakes and ponds |
low nutrients and high oxygen condition |
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Eutrophic lakes and ponds |
high nutrients and low oxygen conditions FL's Okefenokee Swamp-lots of decaying matter and warm. Warm but lots of debris and vegetative matter naturally put there |
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Diff b/w temperature and dissolved oxygen |
warmer=lower oxygen colder=more oxygen |
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Eutrophication |
Where there's an ogliotrophic lake connected to a river where a lot of fertilizers are dumped in (have lots of nitrates and phosphates) In this process, nutrients like nitrates and phosphates are introduced into a water body If get large influx of nutrients, causes algae to rapidly reproduce, causing an algal bloom Algae will produce oxygen and take up those nutrients--good thing but it'll end up dying Dies, sinks to the bottom where bacteria begins decomposition Process uses up oxygen in the water, so animals die Happens in lakes, ponds, and the ocean |
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Dead zones |
Area of ocean not a lot of oxygen and organisms don't live there Mississippi will collect nutrients and go into the Gulf of Mexico and cause a dead zone in the gulf Climate change--causing lots of dead zones b/c oceans are getting warmer, so less oxygen Putting in nutrients, get more algae, etc. |
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Wetlands |
Include marshes, swamps, bogs, and seasonal pools Soil is saturated with shallow standing water Acts as a natural flooding protective system |
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Freshwater marshes |
Shallow water Plants grow above the surface |
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Swamps |
Shallow water in forested areas Trees-maybe even dead trees which animals can live in Can be made by beavers Some of the cleanest water b/c wetlands filter it Brown b/c of leaves--like tea As leaves decompose makes it look brown, but water is really clean. A little acidic b/c of needles and stuff falling in it, but normal and healthy to be a little lower than we think is normal |
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Bogs |
Ponds covered in thick, floating mats of vegetation A stage in aquatic succession |
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Wetlands value |
Extremely valuable for wildlife -Slow runoff, reduce flooding, recharge aquifers, and filter pollutants People have drained wetlands, mostly for agriculture -Southern Canada and the US have lost half their wetlands Laws determine when to protect wetlands |
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Groundwater |
water beneath the surface held in pores in soil or rock underground water from aquifers or wells, drill down to reach groundwater 20% of the Earth's freshwater supply average age is 1,400 years, may be tens of thousands of years old. not as easy as it seems to get water from aquifer recharge process can take a long time and it's really old water groundwater becomes surface water through springs or human-drilled wells |
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Aquifers |
porous, sponge-like formations of rock, sand, or gravel that hold water zone of aeration, zone of saturation, water table |
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Zone of aeration |
pore spaces are partly filled with water |
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Zone of saturation |
spaces are filled with water |
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Water table |
boundary between the two zones |
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Recharge zone |
any area where water infiltrates Earth's surface and reaches aquifers |
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Confined (artesian) aquifer |
water-bearing, porous rocks are trapped between less permeable substrate (clay) layers under great pressure |
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Unconfined aquifer |
no upper layer to confine it readily recharged by surface water |
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The Ogallala Aquifer |
the world's largest known aquifer underlies the Great Plains water has allowed farmers to create the most bountiful grain-producing region in the world hydraulic fracturing-done a lot here and uses a lot of water to crack the underground areas to get to oil and then pump it back up evidence supporting when they do it they're cracking, getting groundwater, and contaminating it |
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Climate change & water |
May bring shortages Causes: altered precipitation patterns, melting glaciers, early season runoff, intensified droughts, and flooding Seeing effects now, not just coming in future |
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Altered precipitation patterns |
Lake affect snow--pick up moisture across the lake and dump it on the eastern side of the lake California's drought |
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Early season runoff |
get snow but winter ending earlier so not enough water to get them through to the next snow in the following year runoff earlier so people dependent on the water supply don't get enough to last as long as they need it |
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Flooding |
Even in CA where there's a drought get floods when it rains b/c ground is like concrete and all the water just runs off. Needs slow, gentle rain for a while so it softens and can absorb the water |
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Humans and water |
Impressive engineering accomplishments to harness freshwater 60% of world's largest 227 rivers have been strongly or moderately affected Dams, dikes, and diversions--while dams are good, they block nutrients Everything has pluses and minuses Consumption of water in most of world is unsustainable |
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Unsustainable consumption of water |
How? pulling water from underground and distributing it other places. takes a long time to recharge and that's not happening now. Depleting surface water as well. Water in it never makes it to the Pacific Depleting many sources of groundwater and surface water |
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Uses of water |
Supplies houses, agriculture, and industry Amount of type of use changes depending on nation Arid countries use water for agriculture Developed countries use water for industry Consumptive and non-consumptive use |
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Consumptive use |
Water is removed from an aquifer or surface water body and is not returned Irrigation--the provision of water to crops Using water to make alfalfa and sending it to China |
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Nonconsumptive use |
Does not remove, or only temporarily removes, water Electricity generation at hydroelectric dams Taking water from the Chattahoochee and it later ends up back in the Chattahoochee from the water treatment plant |
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Hydroelectric dams |
When there's a top lake and need to generate power they run it through the turbines and it goes into the lower lake where usually goes back to a river but it's also dammed and when there's not a lot of demand for electricity they pump it back up to the main lake to make more electricity later Regenerates and repumps the water, so nonconsumptive |
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Why does agriculture use so much water? |
Rapid population growth requires more food and clothes The Green Revolution uses irrigation--we use 70% more irrigation water than 50 yrs ago Irrigation can double crop yields--18% of land is irrigated but produces 40% of our crops Irrigation is highly inefficient--water evaporates in "flood and furrow" irrigation Overirrigation leads to water logging and salinization--reducing world farm income by $11 billion |
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Governments subsidize irrigation |
Irrigation subsidies promote food self-sufficiency, but irrigation uses up huge amounts of groundwater for little gain Water in the Colorado River Valley is diverted for cotton and other crops grown in the desert Farmers in California's Imperial Valley pay only a penny for 220 gallons of water |
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Divert surface water for our needs |
People divert water to farm fields, homes, and cities Once mighty CO River has been extensively diverted and used |
