WATER EQ2

Question 1

What is a drought?

Answer 1

they exist when there is a deficit compared to normal precipitation levels

Question 2

What are the four types of drought, in order of severity?

Answer 2

Meteorological, hydrological, aagricultural, famine

Question 3

What is a meteorological drought?

Answer 3

defined by shortfalls in precipitation as a result of short term variability within the overall long term average shown in many arid/semi arid areas eg. the Sahel
-becoming more common as recent trends of rain are decreasing in frequency severity and duration

Question 4

What is a hydrological drought?

Answer 4

Associated with reduced stream flow and ground water levels which decrease because of reduced inputs of precipitation and high rates of evaporation
- this causes reduced water storsage in lakes and reservoirs with marked salination and poor water quality.

Question 5

What is an agricultural drought?

Answer 5

The rainfall deficiency from meteorological drought leads to deficency of soil moisture and soil water availability which has a knock on effect on plant growth and reduces biomass

Question 6

What is famine drought?

Answer 6

a humanitarian crisis in which the widespread faliure of agricultural systems leads to food shortages and famine with severe social, economic and enviromental impacts

Question 7

What is famine drought?

Answer 7

a humanitarian crisis in which the widespread faliure of agricultural systems leads to food shortages and famine with severe social, economic and enviromental impacts

Question 8

What are some measurements that could be taken to monitor and record drought?

Answer 8

rainfall
temperature
soil moisture
river flow
surface storage

Question 9

What is the PDSI?

Answer 9

Palmers Drought Severity Index
uses readily available temperature and precipitation data to estimate relative dryness.
standard index: -10 dry to +10 wet

Question 10

What are the physical causes of drought?

Answer 10

phenonemons
late monsoon seasons
heatwaves
long absences of rainfall

Question 11

What are the human causes of a drought?

Answer 11

climate change
over abstraction of ground water
politics/goverments
deforestation
soil degredation

Question 12

What is an ENSO cycle?

Answer 12

the El Nino Southern Oscillation
is a natural climate pattern in the tropical pacific ocean that fluctuates between warm and cold phases known as El Nino and La Nina, in an irregular cycle of 2-7 years

Question 13

What is the El Nino phase of the ENSO cycles?

Answer 13

changes to sea surface temperature in the souther pacific ocean.
makes weather wetter over south America and drier over Australia and southeast Asia.

Question 14

What is the La Nina phase of the ENSO cycles?

Answer 14

creates wetter wether over the western pacific ocean. creates drier conditions over the south pacific and drier conditions over south America and wetter over Australia and Southeast Asia.

Question 15

Which regions experience drought conditions in an El Nino year?

Answer 15

Africa, Latin America and south east Asia

Question 16

What is the atmospheric circulation model?

Answer 16

a simplified version of how our currents in the atmosphere move.
used to help explain weather patterns and climatic regions

Question 17

What is the ITCZ?

Answer 17

The Inter Tropical Convergence Zone
- an area of the tropics characterise by low pressure due to action by the hadley cell.
- earth tilts by 23 degrees so that sunlight is concentrated on different places throught the year
wet/dry climates change. Northeast trade winds mett Southeast trade winds at the equator

Question 18

What is a monsoon?

Answer 18

A particularly wet season lasting several months and happening in pultiple regions.
eg. India and west Africa

Question 19

What is a blocking high pressure system?

Answer 19

high pressure areas blocking unstable weather from moving in.
can stay for several days, weeks or months.

Question 20

What are some human factors that can lead to drought?

Answer 20

deforestation- decreases interception, more water enters rivers instead of soil water stores

building dams- prevents movement of water to where it is needed

increasing population- urban demand for water is higher so more is abstracted from ground water sources

Question 21

Brazil 2014-15 Drought and its causes (non essential case study)

Answer 21

• 2014-2015 were Brazils worst droughts for 80 years.
• water levels fell in some of the worlds largest HEP (hydroelectric power) schemes
  -power supplies were suspended, agriculture was in crisis, and urban taps ran dry in Rio and Sao Paulo

-blocking high pressure systems diverted its normal predictable rainfall
-increased groundwater extraction
-ground water became the only water source for the poor
-only 30% of wells dug were licensed
-2.5 million illegal boreholes
-aquifers dropping
-DIY wells vulnerable to pollution

Question 22

CASE STUDY: AUSTRALIAN DROUGHT 2019

Answer 22

Physical causes:
-unreliable rainfall
-rivers drying up
-sinking dry stable air
Human causes:
-increasing greenhouse gasses
-over abstraction of water

Impacts
-crop failure
-water restrictions
-increased food price due to importation
-rural communities lacked access to food and water

Role of climate change:
-decreasing average rainfall
-decreasing water flow
-dry sinking air stays for longer

Question 23

CASE STUDY: AUSTRALIAN DROUGHT 2019

Answer 23

Physical causes:
-unreliable rainfall
-rivers drying up
-sinking dry stable air
Human causes:
-increasing greenhouse gasses
-over abstraction of water

Impacts
-crop failure
-water restrictions
-increased food price due to importation
-rural communities lacked access to food and water

Role of climate change:
-decreasing average rainfall
-decreasing water flow
-dry sinking air stays for longer

Question 24

What is an ecosystem?

Answer 24

a community of organisms that interact with each other and their enviroment

Question 25

Why are ecosystems important?

Answer 25

biodiversity improves resources create hydrological systems carbon storage cultural/spiritual value

Question 26

What impact does drought have on forest ecosystems?

Answer 26

foliage loss impaired growth increased succeptibility to pests/disease increased forest fires takes up to 4 years to resume growth rate trees turn from carbon sinks to stores crops failing less pollinating insects

Question 27

What impact does drought have on wetland ecosystems?

Answer 27

increased tree mortality threat of wildfires permanent dry years for rivers changes to grassland

Question 28

What is a water surplus?

Answer 28

An excess of water compared to the demand from the population

Question 29

Why do some areas experience water surpluses?

Answer 29

-meterological causes of flooding include intense storms leading to flash flooding usually heavy rainfall and extreme monsoons, rainfall and snowmelt - human action can exacerbate flood risk (changing land use within river catchment, management of rivers using hard engineering systems)

Question 30

why do places experience flooding? (human factors)

Answer 30

Mismanagement deforestation agriculture changing land use urbanisation

Question 31

Why do places experience flooding? (Physical factors)

Answer 31

-drainagr basin shape -consecutive rainfall events -snow/ice melt -intense storms -ENSO cycles -impermeable soils or bedrock -intense monsoon periods -infiltration max reached

Question 32

CASE STUDY: UK FLOOD EVENT

Answer 32

Meteorological causes: -persistant heavy rainfall, strong winds and antecedant conditions of already saturated ground -Cumbria recorded 341.4 mm of rain over 24hrs (record highs for the UK) Flood risks: -record breaking rainfall -persistent wet conditions -impact of climate change Rain cause: -prolonged intense rainfall from storm desmond which enhanced orographic uplift and already saturated groumd social impacts: -widespread disruption to daily life -displacement of residents -damage to infrastructure economic impacts: -direct losses such as damage to infastructure and buisinesses -indirect losses felt through the regional economy eviromental impacts: -increased erosion -habitat loss -contamination of water sources.

Question 33

by 2100 the UK climate is expected to have…

Answer 33

a warmer wetter climate more extreme weather events hotter drier summers warmer wetter winters

Question 34

How is climate change influencing the hydrological system?

Answer 34

-causing more extreme weather events -impacting water availability -high temperatures increasing evaporation and precipitation

Question 35

How is climate change affecting water stress?

Answer 35

for every 1 degree celsius the global temperature increases, there is a 20% drop in renewable water sources global warming is set to increase the amount of water stressed areas and increase the stress in regions already facing it