The Water Cycle

Question 1

Where is water stored?

Answer 1

The atmosphere
The ocean
Ice caps - cryosphere
Soil
Groundwater
Vegetation
Lakes and rivers

Question 2

What is the difference between blue and green water?

Answer 2

Blue water: water in the form of oceans/ lakes/ rivers
Green water: water stored in vegetation and organic matter

Question 3

Define the global hydrological cycle

Answer 3

The continuous cycle of water between the oceans, the land, and the atmosphere on a global scale. This is a closed system.

Question 4

Why is water a valuable resource?

Answer 4

Most of it is seawater
69% of freshwater is locked up as snow and ice
30% is deep underground
Our water supply is unevenly distributed
Varying residence times
Fossil water- not renewable or reachable for human use
Or very short residence times- we can’t harness the water as it disappears too quickly
This means that only about 1% of freshwater is easily available for humans to use

Question 5

What is a water budget?

Answer 5

Water budgets show the annual balance between inputs
(precipitation) and outputs (evapotranspiration) and their
impact on soil, water availability and are influenced by climate
type ( tropical temperate or polar examples).

Question 6

What two processes drive the hydrological cycle?

Answer 6

Gravitational and solar energy

Question 7

What is fossil water?

Answer 7

Untapped ancient stores of freshwater exist in polar regions and beneath some deserts

Question 8

What is throughflow?

Answer 8

Also known as inter-flow; water seeping laterally through soil below the surface, but above the water table

Question 8

What three components are part of any water cycle?

Answer 8

Stores
Fluxes: which measure rate of flow between the stores
Processes: physical mechanisms that drive the movement of water

Question 8

Label a drainage basin

Question 8

Drainage basin factors

Answer 8

Snow - capped peaks hold water back until thaw - delayed flow
Large drainage basins affected more by precipitation
Forest and vegetation result in more inception
Impermeable soils and rocks prevent infiltration and cause surface saturation
Impermeable urban surfaces
Reservoirs hold water back and create new surface water stores
Grasslands have higher infiltration, percolation, throughflow and evaporation
Steep slopes promote faster movement

Question 9

Define the water balance and why it is important to analyse

Answer 9

Is the balance between inputs (precipitation) and outputs (runoff and groundwater storage) into a river. This affects the river regime (pattern of flow) and is essential to predict flooding, ensure there is enough water in the system to meet human needs, and manage amounts of water extraction from the river.

Question 10

The Water Budget Graph

Answer 10

Soil moisture surplus: after winter in spring there is an abundance of soil moisture that can supply rivers

Soil moisture utilisation: when evapouration exceeds precipitation in the summer and is utlized

Soil moisture deficit: By the second half of the summer there has been so much evapouration that there is a soil defecit

Soil moisture recharge: In winter precipitation is increased and evapouration falls in autumn allowing soil moisture to be recharged

Question 11

Define river regime

Answer 11

The variability in the discharge of a river during the year in response to precipitation, temperature, evapotranspiration and drainage basin characteristics

Question 12

Aral Sea Case study

Answer 12

Formerly one of the four largest lakes in the world with an area of 68,000 km2 (26,300 sq mi), the Aral Sea has been steadily shrinking since the 1960s after the rivers that fed it were diverted by Soviet irrigation projects. By 2007 it had shrunk to 10% of its original size splitting into four different lakes.
Water was required to support the cotton industry (globalisation, human factors)

Question 13

Amazon Case study

Answer 13

The land of the Amazon Rainforest is naturally nutrient-deficient because most of the nutrients are stored within the aboveground biomass of the vegetation. Tree root systems hold the soil together to slow the rate of flooding and reduce erosion. Trees themselves also absorb water during the rainy season. When the trees are removed from the environment, the rainy season can have devastating effects. Rains wash away the vital topsoil and what nutrients are left. Increased deforestation therefore leads to decreased biodiversity and species richness.
Due to slash and burn technique there is no vegetation for inception

Question 14

Hydrographs: Baseflow

Answer 14

Estimate of the water that flows into a river from groundwater flows

Question 15

Hydrographs: Attendant discharge

Answer 15

The discharge before a storm event

Question 16

Draw a hydrograph

Answer 16

Include these labels:
Baseflow
Peak discharge
Peak rainfall
Rising limb
Receding limb
Attendant discharge
Lag time

Question 17

Agricultural drought

Answer 17

Happens when crops become affected due to a lack of supply of surface or groundwater.

Question 18

Famine drought

Answer 18

Happens when there is crop failure on such a large spatial scale that a humanitarian crisis ensues for a region.

Question 19

Meteorological drought

Answer 19

Happens when dry weather patterns dominate an area

Question 20

Hydrological drought

Answer 20

Occurs when low water supply becomes evident, especially in streams, reservoirs, and groundwater levels, usually after many months of meteorological drought.

Question 21

Physical factors affecting drought: Sea temperature

Answer 21

If sea surface temperature changes then this can cause a change in the amount of rainfall different regions receive.

Question 22

Physical factors affecting drought: Soil moisture

Answer 22

When there is moisture in the soil evapouration means that precipitation occurs this prevents drought. When there is no moisture warm air rises without moisture and no rainfall occurs. As warm air rises air rushes to fill the gap this can can erode the soil.

Question 23

Physical factors affecting drought: Atmospheric temperature

Answer 23

Higher temperatures lead to higher evapouration. Water vapour is moved elsewhere by atmospheric circulation.

Question 24

Physical factors affecting drought: Atmopsheric moisture

Answer 24

When there is moisture in the atmosphere, we get rain as air cools and condenses into clouds.

Question 25

Physical factors affecting drought: Lack of rainfall

Answer 25

This means that groundwater supplies are not recharged and therefore less water is reaching rivers leading to a hydrological drought.

Question 26

EL Nino

Answer 26

Normal year:
Wind blows across Pacific east to west.
This drags all the warm water over towards Australia.
Warm water evaporates, cools and condenses and rains a lot over the Western Pacific
By moving all the warm water west, there is room for cold water from the deep to replace the warm water in the Eastern Pacific.

El Nino:
Winds that are blowing from east to west start to become weaker or even reverse
This means that warm water that was being pushed to the west now heads back east.
This means that the central Pacific is now warmest, and thus creates large rainclouds.
This means the rain has been moved away from Australia (and the western Pacific) and instead air descends on this region- creating dry conditions and possibly drought.

Question 27

Why is Australia effected by droughts?

Answer 27

Low variable rainfall because the climate is dominated by the sub-tropic high pressure belt of the Southern Hemisphere
Most Australian droughts are related to El Nino
‘Big dry’ in 2006 is thought to have been associated with climate change leading to a trend of warmer, drier climate for south-eastern Australia

Question 28

The Big Dry

Answer 28

2006
Affected more than half of farmlands especially in the Murray- Darling Basin which provides 50% of the nations agricultural outputs
Disastrous effects on Australia’s exports

Question 29

Australia: water scarcity

Answer 29

South of Australia relies on River Murray for 40% of its drinking water. In recent years it has been over-extracted so much that water no longer flows to the mouth. Resources have been extracted for agricultural, industrial and urban use.

Question 30

Marsh Arabs

Answer 30

Central Marsh of Iraq
Explains Al-Asadi “The town was like Venice. It had more than 1,200 islands, and between each island, there was water and natural canals.”
At their height, these wetlands sustained up to half a million people: Marsh Arabs
who relied on buffalo breeding, fishing, hunting, and a few crops. Their lifestyle
resembled that of the Sumerians who first settled the marshes 6,000 years ago.
But all that has vanished in the intervening years. Saddam Hussein perceived a threat in the Marsh Arabs, accusing them of sheltering Shi’ite rebels. He ordered them all to leave, and built roads into the marshes so that his soldiers could find and expel any who remained. In 1993, he dealt the crowning blow, diverting the water of the Tigris River away from the marshes, into a massive canal called the Glory River.
The Central Marsh was completely dehydrated. A few years after the fall of Saddam, the land around the Glory River also dried up.

Question 31

Regenerating the marshes

Answer 31

After the dictator’s fall, however, locals began to return. With the help
of a bulldozer hired by Nature Iraq for about $350, they broke down the
main embankment that Saddam had built, and water returned to the Central Marsh.
It wasn’t quite the same, however. Since pre-Saddam times, the quality of the water had drastically worsened; salinity levels reach 4,000 parts per million (ppm) now, says Jassim, compared to 200 ppm during the 1960s. The current level of salinization makes it difficult to breed buffalo, and stunts the growth of the reeds.

Question 32

Groundwater flooding

Answer 32

Flooding that occurs after the ground has become saturated from heavy rain

Question 33

Surfacewater flooding

Answer 33

Flooding that occurs when intense rain has insufficient time to infiltrate, so flows overland

Question 34

Primary causes of flooding

Answer 34

Intense rainfall
Snowmelt
Tropical storm
Tidal surge (up a river)
Dam failure

Question 35

Secondary causes of flooding

Answer 35

Steep/slope angle
Soil thickness
Deforestation

Question 36

Physical causes of flooding

Answer 36

Nature of drainage basin
Intense precipitation in ground baked areas (areas that are hard from the sun)
Intense rainfall reduces infiltration
capacity
Climatic hazards (tropical storms)
Rapid snow melt
Coastal influences
Climatological

Question 37

Human causes of flooding

Answer 37

Enhanced climatic hazards due to humans catalyses physical processes
Deforestation
Urbanisation
Land management techniques/agriculture

Question 38

Teweksbury floods

Answer 38

2007
Cost of £3.2 billion
13 people died
48,000 homes affected
Environment Agency is warning that the average annual cost of flood damage could rise by 60% by 2035, unless funding for defences is doubled to £1bn a year by then to protect against climate change.
350,000 people in Gloucestershire were left without tap water after the water treatment works was flooded.
1 in 4 residents from the worst affected areas reported to have suffered significant mental health problems (e.g. depression requiring medication).

Question 39

Climate change: Colorado River Basin

Answer 39

River flows, concluding they would most probably decline by 8.7% by 2060. That’s a loss of 1,300,000 acre-feet, the entire annual capacity of the canal diverting water to Los Angeles, Orange, and San Diego counties.
Now we have confirmation from Reclamation that whatever water is left in the Colorado River won’t go as far. Hotter temperatures will drive an increase in water demand. The average projected increase in water use, based solely on temperature increases, is 500,000 acre-feet.

Question 40

Global warming: Thawing of permafrost affecting drainage basin

Answer 40

Currently, permafrost covers about nearly 5.8 million square miles, and scientists found as much as 2.5 million square miles of that could thawin a 2 degree Celsius scenario. The new research was published Monday in the journal Nature Climate Change.
Permafrost contains vast amounts of carbon in the form of plants that died since the last ice age and have remained frozen rather than decomposing. When permafrost thaws, this long-trapped carbon is released into the atmosphere, further propelling future warming. A 2015 study estimated that the thawing permafrost could release up to 92 gigatons of carbon into the atmosphere by the century’s end.

Question 41

Facts that highlight why water is a valuable resource

Answer 41

• 1.8 billion people lack clean water
• Every 90 seconds a child dies from a water-borne virus
• Half of the worlds rivers and lakes are polluted
• Half of rivers no longer flow all year round

Question 42

What is the difference between water stress and water scarcity?

Answer 42

Water stress (below 1,700 m³
per person) and water scarcity (below 1000 m³ per
person).

Question 43

Physical causes of water stress

Answer 43

Climate
Discharge level
Coastal storm surges and rising sea levels
Annual and seasonal precipitation distribution
Topography
Snowfall and glaciers
Pollution of groundwater reserves
Geology

Question 44

Human causes of water stress

Answer 44

Industrial waste dumped in river
Over abstraction from groundwater sources for domestic, agriculture and industry
Heavy metal toxins from mining
Untreated sewage causing water-borne diseases
Chemical fertilisers causing eutrophication (excessive growth e.g algae) leading to hypoxia (insufficient oxygen)

Question 45

Mexico water crisis

Answer 45

Currently, more than 12 million persons lack drinkable water, especially in rural areas. Water pollution is due to the discharge of domestic, industrial, agricultural and mining residues. Ninety million Mexicans, despite having the infrastructure to receive drinkable water, need to filter their water through domestic purifying systems or buy it at a very high costs from private companies, since purifying plants and distribution networks provided by the government or the individual storage systems do not function properly, thus polluting the vital liquid before reaching the final consumer
Turning drinkable water into a PRIVATE GOOD

Question 46

Preventing water insecurity: The Three Gorges Dam

Answer 46

Designed to control flooding in Yangtze, improve water supply by regulating river flow, generate HEP
632km^2 have been flooded to form reservoir
1.3 million people have been relocated from 1500 villages. Decomposing vegetation in the resevoir produce methane which is released when water passes through HEP turbines.

Question 47

The South-North Water Transfer Project

Answer 47

Beijing has 35% of China’s population but only 7% of its water. Three routes will take water from the Yangtze to northern China, a western route to the Yellow River, Eastern route via a series of lakes and a central route. Cost $70 million due to be completed by 2050. Will reduce water shortages and abstraction of groundwater however, it risks draining too much from Southern China.

Question 48

Israel’s desalination project

Answer 48

Five plants were opened by 2013 taking water directly from the Mediterranean sea. Aims to provide 70% of Israel’s domestic water supplies by 2020. Produces up to 600 tonnes of potable water per hour.

Question 49

Rainwater harvesting Jars in Uganda

Answer 49

Kitayita village has 3,000 people who lack access to safe water. Local builders have been trained in the construction of rainwater harvesting jars which have the capacity of 1,500 litres which provide a stable source of water for many years.

Question 50

Israel water management

Answer 50

Using smart irrigation, where drip systems allow water to drip slowly to plants’ roots through a system of valves and pipes - reducing wastage and evaporation.

Question 51

Water management in Singapore

Answer 51

Traditionally Singapore has been provided 80% of its water from Malaysia by 2010 this halved. Subsidies protect the poorest citizens from expensive water. Per capita water consumption fell from 165 litres per day in 2000 to 150 in 2015 through metering the water supply and educating the public.

Question 52

The Nile case study

Answer 52

11 countries compete for the Nile’s water. The Nile is susceptible to change due to El Nino and El Nina variations. Located in hot arid areas: lots of evaporation.
Over 300 million people live within the Nile basin and this is expected to double by 2030.

Question 53

What percentage of Egypts water needs depend of the Nile?

Answer 53

95%

Question 54

Nile agreement 1929

Answer 54

Between Egypt and the UK granted significant water allocations to Egypt and Sudan making NO allowances for other Nile state countries.

Question 55

Define IWRM

Answer 55

A process which promotes the co-ordinated development and management of water, land and related resources in order to maximise economic and social welfare in an equitable manner without compromising the sustainability of vital ecosystems.

Question 56

Colorado River facts

Answer 56

The river surrounds 7 US states and Mexico
Provides drinking water for 50 million Americans
The river has been in consistent drought since 2000

Question 57

Examples of integrated water management

Answer 57

In 2012 - the US states divided up the shortages. The amount of water available determines supplies to each state. As a result California has reduced the amount it extracts by 20%. In 2012 an agreement called Minute 139 was signed between the US and Mexico which gives Mexico the right to store some of Colorado’s river in Lake Mead. The IWRM prevents greedy upstream behaviour.

Question 58

What stores of water are considered non-renewable?

Answer 58

Fossil water and cryosphere losses

Question 59

Orographic preciptiation

Answer 59

Warm moist air is pushed up as it reaches a mountain and this causes cloud formation and precipitation on one side of the mountain which causes a rain shadow effect on the other side of the mountain which there is less precipitation

Question 60

Convectional rainfall

Answer 60

Usually occurs in the UK during the summer when the sun heats the land this rising air creates convection currents warm air cools and condenses to form clouds the large cumulonimbus clouds can produce heavy rainfall.

Question 61

Frontal rainfall

Answer 61

Occurs when a warm front meets a cold front the heavier cold air sinks to the ground and the warm air rises above it. When the warm air rises, it cools and the cooler air forms clouds producing heavier rainfall.

Question 62

Meteorological causes of flooding

Answer 62

Intense storms leading to flash flooding, unusually heavy or prolonged rainfall, extreme monsoonal rainfall and snowmelt

Question 63

Mekong river

Answer 63

China has the world’s seond largest population and therefore requires a lot of resources including water and energy to sustain this. China has built many dams to generate hydroelectric power 1995 ‘The Mekong Agreement’ There are 430 dams along the entire Mekong 11 dams are in China. Travels through six countries: China, Myanmar, Thailand, Lao PDR, Cambodia and Vietnam.

Question 64

Boscastle 2004 flood

Answer 64

75mm of rain fell in two hours. Is located in a steep valley called Valency Valley. Is located just after the confluence of the River Jordan and River Valency. Human causes: The sewage and drainage system was old and had a smaller capacity and deforestation of the valley sides to make way for agriculture.

Question 65

Chittagong, Bangladesh - management in developing countries

Answer 65

A Coastal Climate Resilient infrastructure Project (2012) supported by the Asian Development Bank (ADB) aims
to ´climate-proof´ the area. The project involves:
-Improving road connections, raising embankments to 60cm above normal flood levels
-Creating new market areas with sheds on raised platforms
-Constructing 25 tropical cyclone shelters, taking account of sea level rise
-Training in climate resistance and adaption measures

Question 66

The hydrological cycle outputs, inputs and flows

Answer 66

The hydrological cycle is a system of linked processes: inputs
(precipitation patterns and types: orographic, frontal,
convectional) flows (interception, infiltration, direct runoff,
saturated overland flow, throughflow, percolation,
groundwater flow) and outputs (evaporation, transpiration
and channel flow).

Question 67

Meteorological causes of flooding

Answer 67

Including intense storms
leading to flash flooding, unusually heavy or prolonged
rainfall, extreme monsoonal rainfall and snowmelt.

Question 68

Physical causes vs human causes of water insecurity

Answer 68

The causes of water insecurity are physical (climate
variability, salt water encroachment at coast) as well as
human (over abstraction from rivers, lakes and
groundwater aquifers, water contamination from agriculture,
industrial water pollution).

Question 69

Salt water encroachment

Answer 69

Salinity intrusion has been a serious threat in the downstream areas of Kallada River for more than one and half decades, affecting the groundwater quality of Munroe Island.Physico-chemical analysis of ground water revealed that samples were unsuitable for drinking due to higher content of Na, Ca, and K. Microbiological analysis of island groundwater showed the presence of coliform and E. coli bacteria.

Question 70

The Nile Basin Initiative

Answer 70

Coperation between all Nile countries they will need 1.5 Niles by 2050 to support demand there goal is to achieve water security, share substantial socioeconomic benefits and promote regional peace and security.

Question 71

Ethiopia Dam on the Nile

Answer 71

Grand Ethiopian Renaissance Dam

Question 72

Which countries have not signed the 1995 agreement for the Mekong River?

Answer 72

China and Myanmar

Question 73

Helsinki water convention

Answer 73

The Convention is a unique legally binding instrument promoting the sustainable management of shared water resources, the implementation of the Sustainable Development Goals, the prevention of conflicts, and the promotion of peace and regional integration. In 2003, the convention was amended to allow non-European countries to join.

Question 74

Helsinki water convention successes

Answer 74

2007 The new Franco-Swiss Genevese aquifer agreement is signed. The Genevese Aquifer extends over 19 kilometers underneath the southern extremity of Lake Geneva and the Rhône River across the border between France and Switzerland. Each user is entitled to a 20% extraction margin with respect to its reserved water volume. Extractions in excess of the 20% margin are to be reported to Geneva, permitting Geneva to take certain measures as needed.