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BYU GEO 110 Exam 2
Dr Monson, Chapters 6-11
79
Geography
Undergraduate 1
11/01/2012

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Term
Floodplains - why do people live there?
Definition
People live in floodpalin areas because of the fertile soil, easy/cheap shipping and good fishing.
Term
What are some benefits of flooding?
Definition
1. Maintain wetland habitat
2. It provides natural irrigation - watering the crops
3. Flooding deposits silt in the floodplains, removes salt
Term
What are some flood hazards?
Definition
Drowning
Diseases (typhoid and malaria) from mosquito breeding
Water Pollution
Psychological stress disorders
Property damage
Damage to livestock and crops
Term
What are some countries that especially vulnerable to flooding?
Definition
Bangladesh
Vietnam
Netherlands
Term
What kind of areas are subject to flooding?
Definition
Flood plains - flat ground next to rivers
Coastal areas - storm tides
Small basins and canyons subject to flash floods
Down river from unsafe dams
Low, inland shores (Great Lakes, GSL)
Alluvial fans
Term
What is a drainage basin?
Definition
A watershed. The whole region from which a particular stream collects its water.
Term
What is the closest drainage basin?
Definition
The Provo River Drainage Basin, which we live in.
Term
What is the Levee effect?
Definition
Levees are built to give a measure of protection and control in regards to flooding. However, people then believe the area is safe and begin to develop the land, disregarding the flood potential. Subsequent flooding does not discourage resettlement or redevelopment of the floodplain areas.
Term
Why have recent Mississippi River floods been so catastrophic?
Definition
The floodplains are populated, leaving people and property at a great risk.
Term
Name some flood control devices.
Definition
Levees
Channel improvements (which can backfire)
Flood control dams ad collecting basins
Reforestation after a fire.
Term
What are deltas?
Definition
Low, flat areas of land formed near the mouth of a stream where it enters a lake or an ocean.
Term
What are alluvial fans?
Definition
Fan shaped deposits composed of coarse sediment that is dropped by a stream as it emerges from a mountainfront onto a flatter terrain.
Term
Why is it dangerous to build on deltas or alluvial fans?
Definition
The chance for flooding is high.
Term
Name the main river channel type.
Definition
Straight
Meandering
Braided
Sinuous
Term
Describe a meandering river.
Definition
The river does not move in one straight line, but moves back and forth in a patter. Sandbars occur on the inside bank of the meander.
Term
Describe a braided river.
Definition
When the river divides and comes back together in multiple places.
Term
Describe a straight river.
Definition
Rivers are not naturally straight, especially for long distances. Human make them straight in order to prevent flooding or maintain boundaries.
Term
Describe a sinuous river.
Definition
These rivers has a very gentle bend in them. They are similar to a meander, but not as drastic.
Term
How do dams alter rivers and impact flood potential?
Definition
Dams alter the path and flow of the river. By damming the water, we can generate energy and control the flooding. However, dams put a lot of weight on the earth, seal off areas previously available, and dry out some parts of the original river areas.
Term
What is problematic about straightening river channels?
Definition
Rivers do not naturally run in a straight line. Over time, they will try to move to regain their natural flow that includes bending.
Term
What is a 10 year vs a 100 year flood?
Definition
A one-hundred-year flood is calculated to be the level of flood water expected to be equaled or exceeded every 100 years on average.
Similarly, a flood level expected to be equaled or exceeded every 10 years on average is known as a ten-year flood.
Term
What is discharge?
Definition
The amount of water moving through a cross section of a river per unit of time.
Term
What is sediment load?
Definition
The amount of sediment carried in the water.
Term
Flash flood vs downstream flood
Definition
Flash floods are very isolated whereas downstream floods are prolonged precipitation over a greater area.
Term
What is the National Flood Insurance Program?
Definition
Flood insurance program provided by the Federal Government. The program provides short-term financial aid to victims of floods and establishes long-term land use regulations for the nations floodplains.
Term
What is the cost of landslide prevention?
Definition
The benefit to cost ratio is $10 dollar to prevent $2,000 damage caused.
Thistle, UT Landslide caused $400 Million in damages, but could have been prevented for $400,000.
Term
What do avalanche paths look like in the summer?
Definition
Trees broken and cleared, debris everywhere. Destroyed vegetation easily marks the tracks.
Term
What is Hawaii's Hilina slump?
Definition
A 4,760 cubic mile chunk of the Big Island (Hawaii) is breaking away at the rate of 4 inches per year. This is the Hilina Slump, and it is said to be "the most rapidly moving tract of ground on Earth for its size." The Hilina Slump can move much faster. At 4:48 AM, November 29, 1975, a 37-mile-wide section suddenly dropped 11½ feet and slid seaward 26 feet. The result was a magnitude-7.2 quake and a 48-foot-high tsunami. This was a minor of the slump. If the entire 4,760-cubic-mile block decided to break off, it would probably create a magnitude-9 quake and a tsunami 1,000-feet high. All the coast-hugging cities of the Hawaiian Islands would be swept away. And LOOK OUT Australia, Japan, and California.
Term
How does insurance and disaster aid impact development of slide-prone areas?
Definition
By providing insurance, buyers are more comfortable purchasing a home in a hazard-prone area. Unavailability of ins can discourage unsafe development. Disaster aid is minimal due to limited losses.
Term
Important factors influencing slope failures.
Definition
1. Saturation of slope material with water.
2. Earthquakes
3. Freezing and thawing
Term
Why is soil subsidence a problem?
Definition
-Subsidence results in irregular patterns of ground failure
-Damages roads, buildings, gas lines, water pipes, etc
-Aquifers can't recharge due to sediment compaction
-Loss of land in coastal areas (Louisiana)
Term
the Karst process
Definition
-The dissolving of limestone by (weak carbonic acid) groundwater
Term
Landforms produced through the karsting process.
Definition
Sinkholes
Speleotherm
Haystack Hills
Tufa cones
Term
Types of rock dissolved in groundwater.
Definition
Freshwater: rock salt, rock gypsum
Acidic water: Limestone, dolostone, marble
Term
The sequence of the karsting process
Definition
Water seeps into the ground through cracks, dissolving limestone as it goes.
The water stops at shale, as it does not dissolve it.
As large caverns are dissolved away by groundwater, the topsoil collapses.
Term
What is thermokarst?
Definition
The subsidence of permafrost as the topsoil defrosts in summer and the freezes in winter.
Term
What is the coriolis effect?
Definition
Something traveling over the earth appears to move to the right on its trajectory because the earth is rotating underneath it.
In southern hemisphere everything turns to the left.
There is no coriolis effect on the hemisphere.
Term
What are fronts?
Definition
Air masses between dissimilar air masses.
Cold fronts push in, warm fronts don't move much.
Term
What is the Fujita scale?
Definition
A scale for rating tornado intensity, based primarily on the damage tornadoes inflict on human-built structures and vegetation.
Term
Different forms of severe weather
Definition
Thunderstorms
Tornadoes
Hurricanes
Fog
Drought
Term
Characteristics of thunderstorms
Definition
They are produced mostly by convection as the air over warm areas rises.
They are most common in the tropics because of heat and humidity.
Rare or absent poleward of 60 degrees.
Often produces hail (small in Utah)
Heavy rain kills the storm
Term
What makes thunderstorms dangerous
Definition
Lightening
Term
Where do most tornadoes occur?
Definition
In the United States
Term
Conditions that produce tornadoes.
Definition
Warm, humid air from the south and cool, dry air from the north.
Term
What is wind shear?
Definition
When the air up high is moving faster than the air below.
Term
Characteristics of tornadoes.
Definition
They occur within a frontal storm along a cold front.
They have the strongest of any kind of winds, 60 to 260 mph.
May last few seconds to a few hours.
they have a small path of destruction, travel 30-60 mph.
Term
What makes tornadoes dangerous?
Definition
Flying debris
Term
Hurricane Characteristics
Definition
-The largest, most destructive storms are 100-600 miles in diameter
-Often produce a storm surge
-Often follow the trade winds
Term
Describe the eye of a hurricane.
Definition
10-25 miles in diamter
Calm, because air is subsiding in the middle
Term
Where do hurricanes get their energy?
Definition
They get energy from warm water. When they hit land or cold air, they die quickly.
Term
Requirement to produce hurricanes.
Definition
Ocean water 80 degrees or higher, 150 feet or deeper.
Coriolis effect (which means none start at equator)
Converging winds
Term
Hurricane progression
Definition
Tropical disturbance
Tropical depression - winds less than 39 mph, small area of low pressure, gently rising air
Tropical storm-sustained winds of 39-73 mph.
Hurricane
Term
Oceans with the most hurricanes
Definition
Pacific - 24 per year
Indian and Atlantic tied at 6 per year
Term
Other names for hurricanes.
Definition
Typhoon
Cyclone
Term
What is fog?
Definition
A cloud on the ground.
Term
Circumstances that create fog.
Definition
The air near the ground chills to the dew point temperature. The dew point varies based on the level of humidity in an area, but is the temperature at which water vapor condenses.
Term
When is fog hazardous?
Definition
When is obscures visibility for travel.
Term
What are the foggiest places on earth?
Definition
Pacific Coast
New England
Appalachian Mountains
Term
Why is drought called the creeping hazard?
Definition
It takes weeks to feel. The effects are felt very gradually.
Term
What is drought?
Definition
An unusual dry period that results in a shortage of water.
Term
What makes drought dangerous?
Definition
Famine.
Term
Types of drought
Definition
1. Meteorological - rainfall deficit
2. Hydrological - Stream flow deficit, impacts urban water supply
3. Agricultural - Soil moisture deficit. impacts subsistence farmers.
4. Famine - food deficit. Forces migration, results in starvation and death.
Term
Human causes of drought
Definition
Desertification. Excess pressure on the land from excess cattle
Term
Physical causes of drought
Definition
Teleconnections, linkages to distant climatic anomalies. Like El Nino or La Nina; cold sea temps which produce dry winds.
Term
El nino/la nina
Definition
Equatorial, eastern pacific sea temps get warm, producing hurricanes.
La nina-east pacific becomes cool, producing dry wind.
Term
Famine and drought
Definition
Famine is connected to drought, but the following factors make it worse:
Poverty
Malnutrition
Environmental degradation
Poor governance
Term
Protection against drought.
Definition
Cloud seeding
Water projects: wells and irrigation vs salinization
Term
Heatwaves
Definition
Can cause many deaths.
Chicago has record numbers for deaths.
Term
Desertification in Africa
Definition
Pastoralists followed the rain with their animals. Now, country boundaries prevent them from traveling as they did and animals are overgrazing in the areas where they are stuck. International aid goes to farmers, not pastoralists.
Term
Adjustments and adaptation to severe weather.
Definition
Hazard resistant shelters
Tornado shelters
Escape platforms
Breakwaters
Homes on stilts
Strict building codes
Insurance
Term
Why was Hurricane Katrina so disastrous?
Definition
-Substantial portions of land below sea level
-Coastal areas populated by people who had never experienced a hurricane
-Levee construction resulted in lost barrier island that would have mitigated the effects
-New Orleans has subsided due to groundwater pumping, accumulated sediment discharge weighing down the earth and the levees and pumping systems were over 100 years old.
Term
Highest risk hurricane areas
Definition
-urbanized coasts
-river deltas
-Atolls
Term
Saffir-Simpson Scale
Definition
1-minimal 74-95
2-moderate 96-110
3-extensive 111-130 mph
4-extreme 131-155 mph
5-catastrophic-winds over 155
Term
Extra-tropical clyclones
Definition
occur outside the tropics
Term
Isostatic sea level change
Definition
Local change in sea level due to the height of the land relative to the sea
Term
Eustatic sea level change
Definition
global change in sea level due to changes in density or mass
Term
Barrier islands are formed by
Definition
An accumulation of sand that acts as a barrier to ocean waves. The gradually build upon an existing sandbar
Term
Human structures along the coasts that are supposed to reduce erosion
Definition
groins
jetties
Term
Littoral Transport
Definition
The combination of the the back and forth movement of waves on the beach and the longshore drift carrying sediment parallel to the shore. The result is that the wave hit the shore at an angle.
In th eUS, littoral transport generally moves to the south.
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