Flashcards
Geography Notes
Cards in this deck (31)
- 1FloodsDefinition:
overflows of large amounts of water onto land that is normally dry - 2Types Of FloodsCoastal Floods
Flash Floods
River Floods - 3Coastal Floods: -along coastal areas esp. along low-lying coastal land -caused by intense storms -strong winds = large waves[storm surges]River Floods:
-caused by snowmelt,heavy rainfall or dam failure
-often on floodplains when river overflows on banks
-floodplains are usually flat
-due to it being flat it is more likely to flood - 4Flash Floods: -comes suddenly and lasts a short period of time -can be caused by coastal and river floodsNatural Causes Of Floods
- 5Rainfall-rainfall intensity:rate at which rain falls
-rainfall duration:longer the duration the higher the amount of rainfall
-rainfall frequency:the probability of occurrence of a certain amount of rain falling within a certain period of time - 6Snowmelt-temp. rises = ice melts = flows into rivers
-increase in vol. of water in rivers = river overflow banks = flood surrounding land - 7Storm Surge-sudden increase of sea level along coastline beyond normal high-tide conditions
-during storm,strong winds push waves towards coast creating huge waves - 8Height Of Land Above Sea Level-mean sea level: avg. ht. of surface at a given site over a long a period of time,mid-point between low-tide and mean high tide
-cities on low-lying lands more prone esp. those below sea-level - 9Proximity To Water Bodies-close to water bodies = more prone to flooding
- 10Human Causes Of FloodsFailure Of Man-made structures
- 11-e.g. dams,levees -aim to hold back water hence preventing overflowing of banks when vol. increases -fails when structure break under pressure of high vol. of waterPermeability Of Surface Cover
- 12-refers to the ease water infiltrates ground -vegetated surface=more permeability -concrete surface=less permeability -more concrete surfaces in cities,less permeability-more concrete surface in cities
-less permeability of surface,infiltration,more surface runoff,more prone to floods - 13Channel Capacity-refers to vol. of water held in channel of river without overflowing
-too much rain,channel capacity exceed
-less permeability=need network of canals to remove surface runoff,maintained regularly to prevent clogging - 14Social Impacts Of FloodsInjuries,Spread of diseases and Loss of lives
- 15-injured by objects and debris washed by fast-moving water -buildings collapse=injure/kill ppl. -hypothermia when in water for long time,temp,below 35 Celsius,shivering,confusion,loss of coordination and cardiac arrest-diseases may spread and affect a larger population
-disruption to clean water supply
-ppl. exposed to water-borne diseases when they drink it
-stagnant pools of water,breeding grounds,malaria and dengue - 16-e.g. cholera and dysentery -suffer emotional distress from loss of love ones and homesHomelessness
- 17-property damaged,homes swept away -evacuation to emergency shelters until houses rebuilt -cities with high population density,lots of ppl. homelessDisruption Of Clean Water Supply
- 18-clean water supply disrupted due to damaged water pipes,storage tanks and water pipes -contamination of water supplies when sewage pipes burstEconomic Impact on People
- 19Damage To Machinery And Equipment-machinery and equipment submerged
-electrical components damaged,factories cannot operate full capacity,economic losses
-money spent on new equipment,increased production cost,ppl. lose their jobs - 20Damage To Transport Infrastructure-submerged o damaged during flood,area inaccessible
-time spent plus a lot of money spent on repair
-slow down evacuation an relief efforts
-inability to work=affect economy
-drop in tourist visit - 21Disruption To Energy Supply-roads damaged,gasoline cannot be transported via trucks
-power lines damaged,power disrupted,factories and companies cannot operate without electricity,loss of income
-loss of jobs and power failure in homes - 22Flood Mitigation MeasuresInvestment In Infrastructure
- 23Levees And Floodwater: build higher than floodplains and riversBenefits:
-cheaper to mitigate than to raise height of lands
-act as obstacles and heightens sides of banks,holds water back and prevents overflow of banks - 24Challenges: -regular maintenance needed to ensure strength in preventing floods -costly,some cities do not have the money or manpower for it -has a max. to a certain level,unable to prevent floods above that levelChannel Improvement: make changes to river channel/canal to increase capacity to hold/enable water to flow quickly
- 25Benefits: -more water carried away faster,floods do not occur frequently -moderate value and high-value developments to adj. land,benefits cites with limited land useChallenges:
-creates problem for area downstream
-more sediments carried downstream due to increased erosion,affecting quality of water - 26Zoning: government plans physical development of land and its uses,flood-prone areas often zoned as low-value developments,used for parks and recreational activities,suffer lesser economic lossesBenefits:
-creates space of green areas like parks and fields to help reduce impact of flood damage - 27Challenges: -limited land available for development as only certain area can be use -hard to carry out as there is competing use when land is limited -not abide to recommended land use,still build,hard to enforceElevated Properties: raise properties to a certain ht.
- 28Benefits: -development is protected from floods preventing economic lossesChallenges:
-hard to implement due to increased cost of development
-construction cost increases due to materials and labor needed to elevate a property - 29Forecasting And Warning System: constant and systematic monitoring needed for forecast to be accurate,water level sensors monitor change in ht. of water in canals,flood warnings would be issued to publicBenefits:
-provide information so more time for ppl. to take action to minimise flood damage - 30Challenges: -some cities lack the expertise and technology to collect accurate data and make accurate flood forecastEvacuation: to evacuate most ppl. within least amt. of time,practice makes perfect,evacuate in safe and orderly manner,create awareness and reduce panic along with danger
- 31Benefits: -ppl. educated on what to do when need arises -evacuation drills enable cities to be able to improve flood evacuation plansChallenges:
-limited participation reduces effectiveness of evacuation drill
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- Year 2 Geography Flashcards on Geography Notes, created by Lucy Heartfilia O'Brien on 02/08/2018.
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- Lucy Heartfilia O'Brien
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