- Created by: Alemae
- Created on: 25-05-18 19:03
River regime = the annual variation's in a rivers discharge
- 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
- 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
- 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
Human influences on river discharge
- Deforestation = less infiltration
- Urbanisation = impermeable rock
- 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
The Water budget
Water budget = precipitation - (evaporation + transpiration)
Water budget is the amount of water available for human use
- 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
- What is the water budget?
- How does the climate affect it?
The Hydrological Cycle (A.K.A Water Cycle)
· 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
The Hydrological Cycle (A.K.A Water Cycle) PT. 2
Hydrological cycle - the movement and storage of water through the Earth
- Evaporation - water heats up and becomes water vapour
- Transpiration - water absorbed by plants evaporates
- Channel Flow - downhill movement of water in rivers
- 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
Types of rainfall
Common in tropical areas and U.K. in summer = thunderstorms. Land is hot, air above becomes hot = rises but then becomes cool = rain
When warm air is forced to rise over cold air as it is undercut = condensation, clouds, rain
Hill/Mountains are a barrrier to warm air. Forced to rise = cooling and rain
- How many types of rainfall is there?
- What happens in orographic rainfall?
- What happens in convectional rainfall?
- What happens in cyclonic rainfall?
- Oceans - 97% of all water (residence = 3600 years)
- Cryosphere - 1.9%
- Groundwater - 1.1%
- 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)
- 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?
The causes of drought
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)
- Define the different type of droughts
- How can humans affect drought?
- What is the impact of ENSO?
Australia - "Big Dry"
- 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
- Southern Queensland 2002-3 (East Coast)
- 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
- 85% of annual rainfall concentrated in summer
- 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
- 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?
Ecological impact of droughts
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
- 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
- How does mnsoon season affect Balngladesh?
- How can flash floods have an impact?
- Human causes of flooding?
Tewksbury Floods 2007
- 13 people dead and hundreds evacuated
- 50,000 homes without power for 48 hours
- 9,000 businesses affected
- Total cost to U.K. economy = £3.2 billion
- Sewage polluted agricultural crops
- Destroyed some habitats
- Building on floodplains - Avon and Severn
- Soil saturated already
- Summer of 2007 in UK wettest since reords began = low pressure system
- No flood defences
Climate change impact on The Hydrological cycle
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
- More water in Atmosphere
- More storms?
- 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
- 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?
- 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 and human factors affecting water scarcit
- 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
- 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
More human causes of water scarcity
- 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.
- Deadzones = more than 400 exist = Gulf of Mexico size of New Jersey (hypoxia)
- Green revolution - has chemicals like nitrogen, methane... (carbon)
- 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)
Economic scarcity - Bolivia Privitisation
What was it?
- Structural Adjustment Program by IMF (privitisation a requirement to recieve aid)
- 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.
- 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
- How can privitisation cause water scarcity?
The Aral Sea - water and development (causing scar
- Was once world's 4th largest inland sea
- 2007 - 10% of original size
- 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
- What has physicaly happened to the Aral Sea? How has it created water scarcity?
- What has been the economic impact?
- Social impact?
- Environmental impact?
Israel and Paltestine (International water conflic
- 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
- Palestine people banned from making wells and Israelians move in
- Local Arabs there = 82 m3 year per person (1.4 million of them)
The Mekong (international conflicts)
- 15 large dams already in place in Upper -mekong = China geo-political leverage
- Water - threat of war (social control over South-East Asia)
- 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
Coca-Cola in India
- 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.
- How does this show internal conflicts within a country?
Water insecurity response - Dams
Three Gorges Dam
- World's largest HEP
- Cost $24 billion
- 1.3 million people relocated
- Caused landlides and increased erosion
- Give an example of a dam
- How much did it cost?
- Where there any social impacts?
- How did it affect the area environmentally?
Desalinisation - response to water insecurity
- 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
- 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?
Water Transfers - Response to water insecurity
- 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
- 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?
Integrated Water Resource Management -
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.
- Give an example where IWRM has been successful