Water Cycle Eq2

Question 1

Teleconnections

Answer 1

Climatic anomalies which relate to each other at a large distance. Means that the development of the ENSO within the Pacific Ocean has an impact on climates around the world

Question 2

Humboldt

Answer 2

A cold northbound ocean current, flowing up the west of South America

Question 3

Phytoplankton

Answer 3

Contains chlorophyll and require sunlight to live and grow so found at the water surface. Base of several aquatic food webs. Provide food for a range of animals like whales, shrimp, snails

Question 4

Thermocline

Answer 4

The sharp boundary between the cold deep water and the warmer upper layer

Question 5

The UN definition of drought

Answer 5

An extended period- a season, year or several years of deficient rainfall relative to the statistical multi year average for a region

Question 6

When does a meteorological drought occur?

Answer 6

When long term precipitation is much lower than normal but there is no consensus regarding the threshold of the deficit or minimum duration of the lack of precipitation that turns a dry spell into an official drought

Question 7

When does an agricultural drought occur?

Answer 7

When there is insufficient soil moisture to meet the need of a particular crop at a particular time. Caused by a number of factors such as precipitation shortages, differences between actual and potential evapotranspiration, soil water deficits and reduced groundwater or reservoir levels

Question 8

When does a hydrological drought occur?

Answer 8

When there are deficiencies in surface and subsurface water supplied as measured in rivers, reservoirs, lakes and groundwater

Question 9

When does a socio-economic drought occur?

Answer 9

When the water demand for social and economic purposes exceeds water availability. This could be the result of weather related shortfall in water supply or the overuse of the available water supplies

Question 10

ENSO cycles- a normal year

Answer 10

1. Trade winds blow the equator wide and westward across the tropical pacific
2. Winds blow toward the warm water of western pacific
3. Conventional uplift occurs as the water heats the atmosphere
4. Trade winds push the warm air upwards along eat cost of Peru, shallow position of thermocline
5. Upwelling of nutrient rich cold water
6. Sea levels in Australia 50cm higher than Peru and sea temperatures 8°c higher
7. Walker loop returns to the air

Question 11

La Niña year

Answer 11

1. Stronger trade winds push warm water westwards, giving a sea levels up to 1m higher in Indonesia and the Philippines
2. Low pressure over the western pacific becomes lower and high pressure over the eastern pacific becomes higher
3. As a result rainfall increases over south eat Asia and South America suffers drought
4. Trade winds strengthen due to increased pressure difference between the two areas

Question 12

El Niño year

Answer 12

1. The piled up water which would normally occur in the west moves back east, leading to a 30cm sea level rise in Peru
2. Warmer waters develop in the eastern pacific with temperatures rising by 8°c
3. Rising air causes low pressure to form creating heavy rainfall over the eastern pacific
4. The descending air in the western pacific then creates drier conditions which lead to drought in locations such as Indonesia and Northern Australia

Question 13

Physical causes of drought in Australia

Answer 13

-climate is dominated by the sub tropical high pressure belt

-shift in rainfall patterns with the eastern area becoming drier

-el niño events e.g East coast drought in Queensland in 2002-2003

Question 14

Human causes of drought in Australia

Answer 14

-population growth leading to an affluent water consuming lifestyle

-anthropogenic climate change

-over extraction of the river Murray so no water flowed at its mouth

-increased greenhouse gas emissions

-surface groundwater extracted for agricultural, industrial and urban usage

Question 15

Drought impacts in Australia

Answer 15

-food shortages as farmers rely on water for irrigation for rice and fruits

-impacts on food supply, wheat, wool and meat exports

-the ‘big dry’ lead to a trend of warmer drier climate for South- eastern Australia

Question 16

Physical causes of drought in the Sahel region of Africa

Answer 16

-2015/2016 El Niño increased water stress and temperature rose by 2°c with lower rainfall

-similar to the 1972/1973 drought

Question 17

Human causes of drought in the Sahel

Answer 17

-air pollution from sulphur based aerosols generated in Europe and North America

-demand for food and water rising leading to desertification

-Sahel region is poor so it can’t handle the drought

-world highest poverty and development rates

Question 18

What is a wetland?

Answer 18

A land area saturated with water either permanently or seasonally

Question 19

Importance of wetlands

Answer 19

Act as temporary water stores, giant water filters by trapping and recycling nutrients, high biological productivity and support a very diverse food web and provide resources for humans e.g fish and fuelwood

Question 20

Drought impacts

Answer 20

Less interception as vegetation will deteriorate, less infiltration, less percolation to groundwater stress, drying can accelerate destruction by wildfires

Question 21

What is a forest?

Answer 21

An area with many trees and vegetation

Question 22

Importance of a forest

Answer 22

Ecological functions and services including water shortage and regulation of hydrological processes, timer production, wildlife habitat, carbon sequestration and recreational opportunities

Question 23

Drought impacts on the forest

Answer 23

Foliage loss, impairing growth, increased accumulation of pests and disease and damage to vascular tissue, impairing water transport

Piñon pines become more susceptible to pine bark beetle attacks and bark beetle outbreaks

Question 24

Surface water flooding

Answer 24

Flooding that occurs when intense rainfall has insufficient time to infiltrate the soil, so flows over land. Common when the area has been urbanised and there are impermeable surfaces

Question 25

Groundwater flooding

Answer 25

Flooding occurs after the ground has become saturated from prolonged heavy rainfall

Question 26

Jökulhlaup

Answer 26

A type of glacial outburst flood that occurs when the dam containing a glacial lake fails

Question 27

Drainage density formula

Answer 27

Total length of streams (km) / size of drainage basin (km2)

Question 28

Prolonged heavy rainfall

Answer 28

-Usually in autumn or early winter there are low pressure systems causing prolonged and heavy rain.
-The degree of flooding depends on the precise depression sequence which blocks all high pressure systems

Question 29

Seasonal monsoon rainfall

Answer 29

-In areas of southern and Eastern Asia around 70% of annual rainfall occurs during 100 days
-Half of the country of Bangladesh is less than 12.5m above sea level meaning that when a flood occurred $290 million of crops were damaged, 25 million homeless and 2000 dead

Question 30

Intense storms

Answer 30

-In July 2010, Pakistan received 9000mm of water in one week, ten times the yearly average
-Led to local flash floods and landslides which led to flooding of all major rivers downstream

Question 31

Snow and ice

Answer 31

-Melting snow in late spring with very limited infiltration occurs as ice is still melted underneath
-E.g Dig Tsho glacial lake in Eastern Nepal in 1985, led to a 5m wave ice avalanche overtopping the moraine dam leading to a loss of $1.5 million

Question 32

Local conditions (secondary causes)

Answer 32

-The Carlisle floods, 2005 happened as upper parts of catchment were dominated by mountains therefore encouraging rapid surface run off
-It was also built on the floodplain of the river Eden and close to confluence of three rivers

Question 33

Human causes of flooding- urbanisation

Answer 33

-Increases flood risk as impermeable surfaces are increased for things such as roads
-This increases surface run off
-Shorter lag times due to urban drainage systems
-Bridges and culverts divert water under infrastructure
-In London 60% of residents have paved over their front gardens for car parking

Question 34

Human cause of flooding- floodplain drainage

Answer 34

-Provides land for agriculture and expansion of urban areas
-Reduces natural storage capacity of the flood plain
-Land may shrink as it dries and becomes lower so it is even more likely to flood

Question 35

Human cause of flooding- deforestation

Answer 35

-Deforestation reduces interception and evapotranspiration
-Results in increased surface run off which causes precipitation to reach the channel faster
-Results in flashy hydrographs
-Leads to exposes soil so erosion occurs at a faster rate which increases river sediment load which increases the likelihood of flooding
-Nepal and Tibet increase frequency or flooding in Bangladesh from Ganges and Brahmaputra rivers

Question 36

Human cause of flooding- flooding mismanagement

Answer 36

-Attrications in the drainage basin which will effect downstream
-Hard engineering reduces frequency of floods e.g embankments
-Keswick built 5m high walls along the river Greta
-In 2015, levels rose above the wall to 5.9 metres

Question 37

Flood frequency formula

Answer 37

T = n + 1/ M

T= recurrence interval
N= number of years of observation
M= rank order

Question 38

Bangladesh floods 2007- Human causes

Answer 38

-Dhaka now has over 1 million people due to urbanisation
-Rapid deforestation in the Himalayan mountains to make space for. Houses and farmland and to provide timber
-One of the poorest countries in the world with a GDP of $300 per person
-Unable to afford flood defences

Question 39

Bangladesh floods 2007- Physical causes

Answer 39

-Low lying country at the base of Himalayan mountains
-Most of the country lives on the delta of three large rivers: Ganges, Brahmaputra, Meghria
-Snow on the mountains melts in spring
-Monsoon climate, 80% of rain falls in 3 months of the year
-Suffers from tropical cyclones bringing heavy rain and storm surges which cause coastal flooding
-The long duration of heavy rainfall saturates the soil, increasing surface run off and increasing discharge

Question 40

Social effects of Bangladesh 2007 floods

Answer 40

-An estimated 25 million people were made homeless, 112,000 houses were destroyed in India as porous mud brings became saturated by flood water
-Over 2000 people died as people were reluctant to evacuate and didn’t want to leave livestock behind
-Wells became polluted with sewage causing a lack of clean drinking water and over 100,000 people caught water borne diseases

Question 41

Economic effects of Bangladesh 2007

Answer 41

-Cost of the flood was estimated at $1 billion including damage to crops and property
-Factories were closed around Dhaka, due to flood damage and loss of raw materials, this leads to unemployment
-Widespread loss of livestock, since 80% of Bangladesh rely on agriculture many lost their livelihoods
-$290 million of crops were damaged in the initial floods

Question 42

Environmental effects Bangladesh 2007

Answer 42

-The main highway connecting Dhaka to the rest of the country was flooded isolating the capital
-Transport and other infrastructure disrupted meaning that emergency supplies could not get through
-2.2 million acres of damaged crop land
-Rivers polluted with sewage
-10,000km of roads were destroyed and landslides blocked roads in the highlands of Nepal and Assam

Question 43

Short term management Bangladesh 2007

Answer 43

-Domestic and international flights suspended during July
-$150 million of aid was sought by Bangladesh and Saudi Arabia pledged $50 million and 5 planes worth of food and medicine
-Government worked with NGOs to provide emergency relief in the form of rice, clothing, medicine and blankets
-Bilateral aid from other countries was directed to the Un management team

Question 44

Long term management Bangladesh 2007

Answer 44

-Many local people worked together to rebuild their homes and lives in self help schemes
-World bank provided Bangladesh with a 5 year loan following the 2004 floods to pay for infrastructure, water resource management and education
-Clearing of old canals has allowed a more efficient drainage system allowing water to drain away more efficiently

Question 45

Storm Desmond 2015

Answer 45

-2 flood related deaths
-Around 16,000 properties in England were flooded
-£24 million had been spend on emergency payments to households and businesses, 3,000 families were helped into alternative accommodation
-£200 million in additional funding for flood recovery
-Footpaths and wells were washed away and ground severely

Question 46

Impacts of climate change

Answer 46

-wetlands dry up
-less water available
-rivers dry up from increased evaporation
-increased flooding
-dryer soils

Question 47

Ways to adapt for climate change

Answer 47

-more space to rivers
-make the ground permeable
-wooded banks around rivers
-keep water in soil by replanting hedges
-free rivers from channelisation
-stop wasting water
-improve irrigation techniques

Question 48

Impacts of short term climate change

Answer 48

-increased intensity and frequency of droughts as a result of global warming
-more frequent cyclone and monsoon events threaten water supplies intermittently
-increases in annual temperature leads to greater evaporation from surface water and reservoirs in summer although spring discharge may increase