Hydrological cycle breakdown

River regime = the annual variation's in a rivers discharge

Why?

• Climate and seasons - can affect precipitation going into river (e.g. Colorado River with Sierra Nevada Mountains or The Mekong and the Himalayas - snow melt) and evapotranspiration

• Geology and soil type  - permeable rock/soils as stored as groundwater - released into river as base flow

• Vegetation cover - wetlands can hold water and release slowly

Questions

• What is a river regime?
• Identify 3 physical factors impacting it

Drainage Basin = area of land drained by river and tributaries

Physical factors on Drainage basins

• Climate - influences precipitation type and amount and vegetation
• Soils/geology = impacts throughflow through infiltration - aquifer impact
• Vegetation = evapotranspiration/infiltration/interception
• Relief - affects run-off (gradient)

Human factors on Drainage basins

• Deforestation - less evaporation = surface run-off increase
• Urbanisation - less infiltration
• Dams, etc. - increased evaporationpotentail
• Abstraction - groundwater stores/aquifers

Questions

• Define drainage basin
• Identify physical factors impacting drainage basin
• Identify human factors impacting drainage basin

Storm Hydrograph - shows variation of river's discharge over a short period of time

Physical influences on river discharge

• size of basin =takes less time for water to reach gauging stations
• drainage density = more streams/rivers per unit = water moves quickly
• relief = more surface run-ooff
• vegetation = low density of vegetation = less infiltration = more surface run off
• Saturation

Human influences on river discharge

• Deforestation = less infiltration
• Afforestation
• Urbanisation = impermeable rock

Questions:

• Define what a storm hydrograph is
• Identify 3 physical influences on river discharge and lag time
• Identify 3 human influences on river discharge and lag time

Water budget = precipitation - (evaporation + transpiration)

Water budget is the amount of water available for human use

Influences:

• Climate - increased temperature increases rate of evapotranspiration so less water. Affects type of preciptation (snow, etc.) and well as length/duration. (monsoon) Drought can also kill vegetation = less infiltration

Questions

• What is the water budget?
• How does the climate affect it?

Key Points

·         IT IS A CLOSED SYSTEM (meaning no external factors can influence it)

·         It is driven due to solar power (sun) and gravity

Inputs in the water cycle

·         Precipitation - type (rain,snow) and dependent on seasons. Type of rainfall (orographic, frontal, convectional)

Fluxes in Water cycle (when water is moving)

·         Interception - absorbtion of water by lfat surfaces (leaves)

·         Infiltration - absorbed into soil

·         Throughflow - water heading down slope through soil

·         Groundwater flow - movement of water underground

·         Surface run-off - water at the top

·         Precolation - absorbed into rock from soil

Hydrological cycle - the movement and storage of water through the Earth

Outputs

• Evaporation - water heats up and becomes water vapour
• Transpiration -  water absorbed by plants evaporates
• Channel Flow - downhill movement of water in rivers

Questions:

• What is the "Hydrological cycle"?
• Identify an input in the hydrological cycle
• Identify 3  flows within the hydrological cycle
• Identify 3 outputs in the hydrological cycle

Convectional rainfall:

Common in tropical areas and U.K. in summer = thunderstorms. Land is hot, air above becomes hot = rises but then becomes cool = rain

Cyclonic rainfall:

When warm air is forced to rise over cold air as it is undercut = condensation, clouds, rain

Orographic rainfall

Hill/Mountains are a barrrier to warm air. Forced to rise = cooling and rain 

Questions:

• How many types of rainfall is there?
• What happens in orographic rainfall?
• What happens in convectional rainfall?
• What happens in cyclonic rainfall?

Water Stores:

• Oceans - 97% of all water         (residence = 3600 years)
• Cryosphere - 1.9%
• Groundwater - 1.1%
• Rivers,Lakes
• Atmosphere - smallest amount of all stores               (residence = 10 days)
• Soil Moisture

Notes - fossil aquifers are non-replenishable = not sustainable

Only 2% of all water in world is freshwater and of that, only 1% is surface water (87% is in ice and 12% groundwater)

Questions

• How much water in the world is freshwater?
• How much of that is in ice and ground twaer?
• How much is surface water?
• How much water globally does the oceans contain?
• For how long does it stay in the ocean?
• How much water in the cyrosphere?
• How much water in groundwater?
• How big is th atmosphere as a store? How long does water stay there?
• Name two other stores of water?
• What is the problem with fossil aquifers?

Tpes of drought/why

• Meteorological drought - less precipitation either short-term or trends like climate change (Sahel - Africa)
• Agricultural Drought - due to over-grazing, irrigation = desertification
• Hydrological Drought - reduced stream flow and groundwater levels due to less rain(U.K. 1973 - minister for drought appointed)
• Famine Drought- food shortage crisis = social, economic, environmental impact (Horn of Africa 2012-2014)

Note - HUMANS DO NOT DIRECTLY CAUSE DROUGHT! INDIRECTLY, YES. 

• ENSO -  Has the power to change climate across more than half of the Earth – most powerful earth phenomena – disrupts weather patterns globally ( 50 days late – rainy season in South Africa)

Questions:

• Define the different type of droughts
• How can humans affect drought?
• What is the impact of ENSO?

• 30% of Australia usually affected by drought in any year

Big Dry 2006

• Nationwide - 1 in a 1000 year event
• Affected everywhere, particuarly Murray-Darling Basin = 50% of Australia's national agriculture output.
• Needed for irrigated farming
• Reservoirs fell to 40% of original capacity
• Per capita water consumption = one of highest in world
• Associated with climate change

El Nino

• Southern Queensland 2002-3 (East Coast)

Questions:

• How bad in Austrlia affected by drought?
• How did it impact the Murray-Darling Bain?
• What happened to reservoirs?
• Water consumption per capita?
• What was the Big Dry associated with?
• When has El Nino caused drought in Australia?

• Human factors = act like a positive feedback loop enhancing impact

Physical factors

• 85% of annual rainfall concentrated in summer
• Semi-arid

Impact

• 1999-2000 Ethiopean-Eritrean Drought = 10 million people needed food assistance
• Overgrazing by cattle
• Population doubling every 20-30 years
• Agriculture rain-fed
• The two countries at war with each other = blocked food access

Questions:

• What hysical factors made the drought worse?
• When was the drought?
• How many people needed fos assistance?
• How did agricultre and cattle worsen the situation?
• What about population?

Why they are useful to Earth

• Wetlands - cover 10% of Earth's surface
• Act as temporary water stores - recharges water aquifers and stops eroision
• Helps to maintain water quality by trapping and recycling nutrients
• Carbon store

Destrution via drought and humans

• Less interception = vegetation deterioration due to drought
• Wildfires (California 2017 - 5,000 acres burnt in total)
• Development - Europe and USA = 2.5 million square kilomeres been dstroyed
• Exploiting fuel resources like peat = wetland habitat loss
• Jonglei Canal Project = White Nile from Sudd Swamp to Suth Sudan dry areas
• Dams on the Tigris and Euphrates = S. Iraq marshlands almost completely destroyed

Questions:

• Why are carbon stores important?
• Identify physical factors leading to wetland destrution
• Identify human factors leading to wetland destruction

UK Cockermouth 2009 flooding (flash flood)

• P C Bill Barker died
• 314 mm of rain in 24hrs
• Confluence - Derwent and Cocker
• £28,000 per house in damages

Bangladesh (snow met and monsoon)

• 80% of Bangladesh's rainfall - june to october
• End = 1/3 of country underwater
• Himalayas - feeds Mekong etc.

Causes of flooding

Human = deforestation, urbanisation, building on floodplains, straightening rivers, dams

Physical = saturation, prolongued rain, flash flood, drought = flooding

Questions

• How does mnsoon season affect Balngladesh?
• How can flash floods have an impact?
• Human causes of flooding?

Social impacts

• 13 people dead and hundreds evacuated
• 50,000 homes without power for 48 hours

Economic impacts

• 9,000 businesses affected
• Total cost to U.K. economy = £3.2 billion

Environmental impacts

• Sewage polluted agricultural crops
• Destroyed some habitats

Why?

• Building on floodplains - Avon and Severn
• Soil saturated already
• Summer of 2007 in UK wettest since reords began = low pressure system
• No flood defences

How will climate change affect the water cycle?

• More CO2 and greenhouse emissions = enhanced greenhouse effect = more land heat
• Affects ENSO, evapotranspiration and temperatures globally
• Drought
• More water in Atmosphere
• More storms?

Facts:

• A 1 degree rise in temperatures could increase global run-off by 40%
• In the past 30 years, droughts have  become more widesread and persistent

Questions:

• Identify 3 ways in which climate change may affect the Hydrological Cycle
• Give a piece of eidence to support your claim
• Why is it difficult to say definitively how climate change will impact the water cycle?

Key Terms

• Virtual Water - hidden flow of water in commodities and trade
• Water Stress - annual supply of water per person BELOW 1700m3
• Water scarcity - annual supply of water per person BELOW 1000m3
• Economic Scarcity - fresh water sources limited because of lack of money, governance or tech
• Physical Scaricty - when more than 75% of regions blue water flows being used. (25% of world)

Why not enough water?

• 60% of world's water supplies in just 10 countries
• 66% of world population lives in places with 25% of world's annual rainfall
• Rising middle class (emerging countries = more consumption  - toilet =8 litres) Rich countries use up to 10x as much water per head
• Population growth - 8 billion by 2030 (food = irrigation)

Physical factors

• Geology = controls distribution of aquifers (water bearing rocks) = groundwater storage. Permeable rock absorbs - can't be evaporated - all year supply
• Climate = global distribution oof water, seasons, monsoons, ENSO, climate change
• River regimes = Amazon River has annual discharge of 175,000 cubic metres per second. Droughts in 2005 and 2010 covered twice the size of California in S. America. Deforestation.
• Distance from sea
• Relief of land

Human factors

• Pollution - trans-national rivers. 1 billion people globally without safe water. 1/3 of all rivers in China highly polluted. 2 milllion cihnese people suffer from water related illnesses. (Cancer-cluster villages - liver and digestive cancers)
• Ground water contamination - Nearly 20% of all wells in Bangladesh unsafe due to high concentrations of arsenic

Industry Pollution

• Fukishima Nuclear Meltdown 2010 = radioactive sludge at bottom of water bodies
• Biggest source of pollution in most of developed world (TNCs, over-population...)

Sewage (Black Water)

• Citarum River indonesia - used as toilet - 400 tonnes of waste of livestock every day. World's most polluted river. Summer = unconscious. 5 million people rely on river supply. Lead concentration = 25,000 times recommended level. 

Chemical fertilisers

• Deadzones = more than 400 exist = Gulf of Mexico size of New Jersey (hypoxia)
• Green revolution - has chemicals like nitrogen, methane... (carbon)

Overabstraction

• Salt encroachment = Italy, Spain, Turkey = falling water tables
• Rivers less reliable - not continual flow
• Agriculture and Industry biggest users of water (70% and 60% respectively)

What was it?

• Structural Adjustment Program by IMF (privitisation a requirement to recieve aid)

What happened?

• TNC Aguas Del Tunari in Charge. Their annual revenue = $14 billin in 2000 v.s. Bolivia's national budget of $2.7 billion. Forced out due to protests.

Problem

• Bolivia has socialist leanings - water is seen as right not commodity
• Oversight of capitalist organisation - not always right way
• One of the poorest countries in S. America

Questions:

• How can privitisation cause water scarcity?

What happened?

• Was once world's 4th largest inland sea
• 2007 - 10% of original size

Why/impacts?

• USSR tried to irrigate to create jobs in unproductive region
• The fishing community once employed 60,000 people. Industry collapsed
• Health issues - weapons testing, pollution - 10% of children die in first year.
• 160/310 bird species left
• Up to 10 million may be foorced to migrate and become environmental refugees

Questions:

• What has physicaly happened to the Aral Sea? How has it created water scarcity?
• What has been the economic impact?
• Social impact?
• Environmental impact?

Facts:

• Israel exploits more than 80% of Palestine's water
• Israel consumers = 370 m3 a year per person
• Palestine consumes = 107 m3 a year per person

West Bank 

• Palestine people banned from making wells and Israelians move in
• Local Arabs there = 82 m3 year per person (1.4 million of them) 

Backgroung Information

• 15 large dams already in place in Upper -mekong = China geo-political leverage
• Water - threat of war (social control over South-East Asia)

Threats

• Cambodia - by 2050 its population is expected to jump from 15 million to 24 million
• Could hinder crop irrigration, fishing and endanger food security
• Exacebates drought conditions

What happened?

• For every 3.75 litres of water used by the plant, it produced one litre of product and a large amount of waste water.
• Plachimada now gets its drinking water through pipes, that provide water for only a few hours once in two days, and through tanker lorries which also arrive once in two days.
• Coca Cola subject to criticism that they are depleting groundwater aquifers in the State of Kerala.

Questions

• How does this show internal conflicts within a country?

Three Gorges Dam

• World's largest HEP
• Cost $24 billion
• 1.3 million people relocated
• Caused landlides and increased erosion

Questions:

• Give an example of a dam
• How much did it cost?
• Where there any social impacts?
• How did it affect the area environmentally?

Dubai

• The "M" station in Jebel Ali
• Cost $2.7 billion
• can produce 140 MIG of desalinised water every day
• Water is free in Dubai
• Leads to overuse as some shopping centres have aquariums and ice rinks
• NOT SUSTAINABLE

Questions

• Where has desaliniation taken place?
• Give a specific plant name
• How much can it produce?
• How much does water cost in Dubai?
• What has this led to?
• Is it sustainable?

Kielder Water

• Cost £167 million to build reservior
• 58 families moves
• The dam and reservoir is in the cheviots hills. Controls water going down the Tyne, Wear and tees and distributes to Newcastle, Sunderland and Middlesborough through pipes
• Generates 6MW - enough for 4,000 homes per year

Questions:

• Give an example of a UK Water transfer scheme
• How much did it cost?
• How many families were moved?
• How does it work?
• How much does it generate in electricity?

What is IWRM?

• IWRM is a broad framework in which decision makers can collaboratively decide the goals of water management and co-ordinate how to achieve them.

Example: - Lerma-Chapala River Basin (Mexico)

• One of world’s most water-stressed basins.

• From 1981 to 2001, Lake Chapala lost 90% of its natural volume and the remaining water was left heavily contaminated
• Now, water quality is improving with around 60 per cent of discharges eliminated
• Finance has been secured to invest in water sanitation and treatment programs.
• Natural capacity of lake restored

• 1970s = move towards IWRM
• after 30 years, the benefits are starting to be realised.

Questions:

• Give an example where IWRM has been successful