Water cycle

Question 1

Where’s all non renewable water held?

Answer 1

Cryosphere (glaciers)
Underground (fossil water), under Kenyan desert there’s enough water to supply the population for 70 years

Question 2

What is a drainage basin?

Answer 2

Area surrounding a river where rain falling on land will flow to that river

Question 3

3 types of precipitation explained:

Answer 3

Frontal - warm air meets cold air, then forced above the cold air, cools down as it rises

Orographic - warm air meets mountain causing it to rise, then cools

Convectional - sun heats up the ground, moisture evaporates, as it gets higher it cools down

Question 4

Where is convectional precipitation more common in?

Answer 4

In tropics and in coastal areas

Question 5

What is interception?

Answer 5

Water landing on vegetation before reaching the ground

Question 6

What is a storm hydrograph?

Answer 6

Way of displaying how the discharge of a river can change over time in response to a rainfall event.

Question 7

What is lag time?

Answer 7

The time difference between the peak rainfall and peak discharge of the river.

Question 8

The height at which a flood can occur is called what?

Answer 8

Bankfull discharge

Question 9

5 physical reasons for river flooding

Answer 9

1.Precipitation type, amount and duration - Heavy short showers cause river to rise quickly, lower lag time.
2.Relief or gradient of the river - river with steeper slopes means less infiltration of water into the ground, flows to river quickly, shorter lag time.
3.Vegetation type and coverage
4.Geology
5.Amount of streams connecting to that river

Question 10

4 human reasons for river flooding

Answer 10

1.Urbanisation - impermeable surfaces, increase in population density as well so more people placed in flood risk areas
2.Deforestation
3.Agriculture - farming practices lead to soil not being able to store as much water
4.Hard engineering - Dredging rivers to make them deeper so prevents flooding, however can increase risk of flooding downstream

Question 11

What does an El Nino event cause?

Answer 11

High pressure air in areas nearing Australia so more droughts there, increasing risk of wildfires

Question 12

What does La Nina event cause?

Answer 12

When normal conditions become more extreme, drier conditions in east by South America and wetter conditions in west (monsoonal conditions)

Question 13

Case study about ENSO effects (Australia drought):

Answer 13

.From 2001 to 2009
.Worst hit area was a basin responsible for 40% of Australia’s agricultural produce
.Crop yields fell and food prices increased
.Millions of sheep died due to dehydration and lack of pasture, causing over 100 000 people employed in agriculture to lose their jobs

Question 14

Case study about ENSO effects (Amazon droughts) :

Answer 14

Climate change has affected evapotranspiration and rainfall patterns in tropical rainforests.
Amazon experienced droughts in 2005 and 2010.
Photosynthesis slowed down during the droughts and less carbon removed.
Forest wildfires causing more carbon to be released.

Question 15

Case study on climate change affecting water sources (California):

Answer 15

Increased temperature means increased evaporation in reservoirs, in 2022 the Shasta lake was at lowest level since records began.
.Less water for California which has high demand, densely populated state
.Low levels of rainfall leading to wildfires
.11 of the years between 2000 to 2015 were drought years
.High temperatures leading to less snow building up in winters, snowmelt provides 1/3 of water in California’s cities and farms

Question 16

Case study on climate change causing benefits (Sahel region):

Answer 16

Since 1996 there have been several wet years in between the droughts, conversion of dry land to productive farmland is possible

The people are taking advantage of this for example in Burkina Faso the farmers have dug improved planting pits to trap rainfall on fields and increase yields

Question 17

Conflict in river Nile:

Answer 17

.Dam built by Ethiopia to increase the water collected, HEP power to contribute to its development
.Countries downstream including Egypt and Sudan affected
.Sudan war is a torn nation so won’t make an effort to stop it but Egypt are against it because less water will decrease its productivity in agriculture.
.Partial agreement reached in 2015

Question 18

All hard engineering strategies to manage water supply and examples:

Answer 18

-Water transfer schemes (South - North transfer in China)
-Mega dams (Three Gorges Dam, China)
-Desalination plants (Saudi Arabia)

Question 19

South-North water transfer project in China:

Answer 19

Taking water water from Yangtze river to the North to cities like Beijing, will help reduce risk of water shortages in that region and reduce abstraction of groundwater as well as promoting economic development

However will cost $70 billion, relocates 345 000 people and risks draining too much water from Southern China

Question 20

Water management in Singapore (4 taps approach):

Answer 20

-Desalination used to meet around 40% of country’s water demand.
-Smart water pricing, people who use high levels of water are charged more.
-40% of country’s water comes from high tech recycled water, one technique used is UV treatment.
-Imported water from Malaysia

Question 21

Example of river with consistently high discharges

Answer 21

Amazon, Brazil:

Fed by Andean rivers outside rainforest region and high evapotranspiration levels

Human actions include deforestation reducing interception and increasing surface runoff, as well as large dams can reduce flow of water below it and increase above

Question 22

Example of river with lower discharge

Answer 22

Murray Darling, Australia:

Most of basin undergoes long periods of drought
Some parts located in rain shadow (water is collected by mountains surrounding river instead)

Lots of its water collected by cities and for irrigation

Question 23

Examples of rivers with lots of variety in discharge

Answer 23

Yukon, Alaska:

Snowmelt can add to river and during cold weather the precipitation is frozen
Rapid rises in discharge as permafrost can make soil impermeable increasing surface runoff

Indus river, South and Central Asia:

Basin largely comprised of igneous and metamorphic rocks which are less permeable, increased surface runoff
Fed by snowmelt of Himalayas

Question 24

Water insecurity in Asia:

Answer 24

-Agriculture uses 90% of freshwater withdrawals in South Asia
-42% of China’s sewage is dumped into Yangtze River each year, 500 000 diarrhoea infant deaths in Asia each year
-Billion gallons of raw sewage dumped into Ganges (India) each day

Question 25

Water insecurity in Americas:

Answer 25

-Changes to rainfall due to El Nino and climate change lead to drought in places like California
-Population growth and expansion of industry (e.g. cotton farming in Texas) is increasing aquifer depletion

-Poor sanitation, only 2% of sanitation in Latin America is treated
-Groundwater contamination from released wastes coming from agriculture, mining and industry

Question 26

Water insecurity in Africa:

Answer 26

-80% of total water used for agricultural uses, leads to less clean drinking water, 19 of world’s 25 countries with lowest access to clean water are in Africa
-Lack of risk preparedness, droughts; flood and storms can displace people

Question 27

Examples of countries with:
1) High water availability and low demand
2)Low water availability and high demand
3) Low water availability and low demand

Answer 27

1)Brazil and Russia
2)Mexico and India (water stressed)
3)Kenya

Question 28

3 ways governments can help with water conservation and examples:

Answer 28

-Reducing domestic water consumption (e.g. 2001 the UK government banned installation of toilets that used more than 6 litres of water per flush)

-Reducing agricultural water consumption
(e.g. More than 2 million small holder farmers in Sub-Saharan Africa are growing drought resistant maize)

-Recycling water, most recycled water can be used for toilet flushing, industry, irrigation and power plants (e.g. done in Singapore)

Question 29

Players in reducing water conflict:

Answer 29

UNECE, UN water convention:

Helps to maintain quality, quantity and sustainable use of trans boundary water resources, maintains cooperation and helps resolving issues

Colorado River storage project:

Numerous treaties and agreements have been established so that water is shared fairly between 7 US states and Mexico
In 2007 new agreement was reached, the amount of water available determined the supplies to each state, resulted in supplies to California reducing by 20%

Question 30

Contrasting water pricing around the world:

Answer 30

1)High in water scarce countries like Papua New Guinea, 50L of water would cost 54% of low income worker’s daily salary

2)High in countries reducing domestic water consumption, Denmark has world’s most expensive water as the government are aiming to cut water consumption of population

3)Low in countries where water isn’t privatized, supply of water in Canada is in public sector, charges consumers 80% less than Germany