water cycle Flashcards
(84 cards)
1
Q
How is total water distributed?
A
oceans store 97.5% and freshwater only stores 2.5%
2
Q
How is freshwater distributed?
A
30% groundwater, 69% cryosphere 0.4% surface water with only 1 % of freshwater accessible.
3
Q
How is surface water distributed?
A
67% lakes,12% soil,10% atmosphere
4
Q
Residence time of different stores?
A
oceans 4000 years, glaciers 1000 years, groundwater 10000 years
5
Q
what are the 2 processes that drive the global hydrological system?
A
Solar energy- heats up water causing evaporation and transpiration with 74% of rain concentrated in the tropics.
Gradational potential energy-transports rain between different stores in form of fluxes.
6
Q
what does a closed system mean?
how are some stores changing?
A
continuous with nothing lost
shift in climatic zone mean some stores are depleting e.g., glaciers.
7
Q
What movement occurs between stores of land and oceans and what is this balance known as?
A
in oceans evaporation > precipitation and on land precipitation > evaporation whilst the difference is made in surface runoff putting them in equilibrium this balance is known as the global water budget.
8
Q
what are the 8 characteristics of polar hydrology?
A
> Freeze-thaw seasonal differences.
> spring thaw causes rapid runoff increasing evaporation tenfold.
> freeze thaw cycle causes release of biogenic gas.
> snow insulates the land and 85% of solar radiation is reflected.
> Permafrost creates impermeable substances.
> Lakes and rivers frozen and limited veg reduces heat absorption.
> characterized by orographic and frontal precipitation and low
humidity.
> annual precipitation less than 200mm
9
Q
What are the characteristics of tropical rainforest hydrology?
A
> Few seasonal differences.
dense veg intercepts and consumes 75% of precipitation.
50-75% of precipitation returned by evapotranspiration cools the air as energy is used during the process.
Rainforests generate their own rain.
less than 25% of rain reaches rivers and surface water.
deforestation reduces evaporation thus reducing local rainfall.
constant high temps, characterised by convectional rainfall and high humidity.
annual precipitation more than 2000mm
10
Q
global water budget definition?
A
The global water budget is the total amount of inputs, outputs and stores of water in the global system.
11
Q
what and where is the biggest flux from ocean to land?
A
steep angle if the sun results in intense Solar radiation causing high evapouration.Trade winds transfer water vapor to ITCZ. Strong convectional currents lift air, so it cools into clouds forming storms, most rainfall is created here so is the biggest flux from ocean to land.
12
Q
why are polar regions important?
A
2/3rds of water is locked up in the cryosphere - where temps are below 0 and frozen as glaciers as its melted its added to the global hydrological system affecting the thermohaline circulation.
13
Q
What is the thermohaline circualtion?
A
A global conveyor belt of warm and cold water,
>where ocean water in polar regions is colder more saline and denser causing it to sink.
> cold sinking water draws in warmer surface water from the tropics.
> the movement of water from the tropics draws cold water from the ocean bottom, to be warmed again.
14
Q
What is the thermohaline circulation?
A
A global conveyor belt of warm and cold water,
>where ocean water in polar regions is colder more saline and denser causing it to sink.
> cold sinking water draws in warmer surface water from the tropics.
> the movement of water from the tropics draws cold water from the ocean bottom, to be warmed again.
15
Q
What isfossil water?
A
Untapped ancient stores of freshwater exist in polar regions and beneath many deserts, now technology allows access to water known as aquifers. Kenya’s Lotikipi aquifer contains around 200billion cubic meters of freshwater, 70 years of Kenya’s supply.
16
Q
What is a drainage basin?
A
A series of rivers and its tributaries operating in a open system where water can be lost or gained. Examples include- Mississippi basin draining 3.3million km and Thames basin draining 16,000km.
17
Q
Watershed definition?
A
an imaginary line around the edges of a basin separating one basin from another.
18
Q
How can a drainage basin lose water?
A
> Evaporation and transpiration to atmosphere.
Surface run-off to the sea
Percolation into groundwater stores.
19
Q
what 3 hydrological processes occur when preciptation occurs?
A
> infiltration into topsoil
surface runoff
evaporation
20
Q
What 3 process occur to delay fluxes between stores?
A
> interception by plants
percolation through rocks to become groundwater.
surface runoff into rivers
21
Q
What is the input into the hydrological cycle?
A
Precipitation- moisture in any form
22
Q
What acts as storage in the hydrological cycle?
A
Interception- temporary storage in plants and buildings before reaching soil.
Vegetation storage- Any moisture taken up by vegetation and held within plants.
Surface storage- any surface water in lakes or ponds.
Soild moisture- Water held in soil.
Groundwater storage- Water held in permeable rocks (AKA aquifers)
Channel storage- Water held in rivers and streams.
23
Q
What are the flows the hydrological cycle?
A
> Infiltration- water entering topsoil.
Throughflow- Water seeping laterally through soil below surface but above the water table.
Percolation- Downward seepage of water through mainly permeable rock under gravity
Groundwater flow- slow moving water that seeps into a river channel.
Surface Runoff-Flow over a surface usually impermeable, frozen or saturated.
24
Q
What are outputs in the hydrological cycle?
A
> evaporation-conversion of water to vapour.
> Transpiration- water taken up by plants and relased as water vapour via osmosis
> Evapourtranspiration-combined effect of evaporation and transpiration
> River discharge- the volume of water passing a certain point in the channel over a certain amount of time.
25
Drainage basin factors
>snow capped peaks hold water until they thaw delaying the flow
>steep slopes promote faster movements and shorter storage times
>permable soils and rocks allow more infiltration and percolation, providing greater recharge of groundwater
>High drainage density (lots of tributaries) means fast water movement across the basin.
>Rural land use permits more natural processes than urban. Grassland has more infiltration, percolation, throughflow and evaporation than arable land.
>reservoirs hold back the flow of water and create new surface stores.
> Large-density basins collect more precipitation and are affected by more basin-wide factors than small basins.
>Low drainage density means slow movement of water across the basin area.
>Forested slopes intercept more precipitation,increase levels of evapotranspiration and reduce surface run-off.
>Impermeable rocks and soils prevent infiltration and cause surface saturation.
>Urban surfaces impermeable so increase surface runoff,evapouration and interception.
26
what are the 3 types of rainfall and where and why do they occur?
Orographic (relief) rainfall - Western side of the UK receives the highest rainfall totals, especially in autumn and winter. Warmer moist Atlantic air from the southwest is forced to rise as it reaches the western uplands. As it rises it cools over high ground forming clouds - producing heavy rainfall over western and northern parts of the UK, air then decends and warms.
Convectional rainfall - Typical of the eastern and south-eastern UK in summer, during periods of high temp ,rainfall created by cooling of sea and it condensing forming clouds and rain, often intense and associated with electrical storms causing flashflooding as soil becomes saturated.
Frontal rain- Brings the most rainfall to the UK over the course of a year. Fronts are formed as part of a low-pressure area (depression), where warmer moist air from the southwest meets colder polar air from the north or north-west. The warmer air is forced to rise over cooler air- forming rain along both warm and cold fronts.
27
What is the rain-shadow effect?
The eastern side of the UK receives less rain than the west because western hills force moist air to rise as it approaches from the Atlantic leading to orographic rainfall from the north and west.
28
How do humans impact drainage basins?
Overabstraction- Thames basin home to 13 million people. Also, one of the driest areas in the UK, averaging just 690mm of rainfall a year. Under pressure from growing water demands abd greater abstraction. Over 40% of Londons' water comes from chalk aquifers, replenished by rain falling on Marlborough Downs, chilterns and north downs on the west north and south of london, abstracting too much water leads to rivers drying up in times of low rainfall.
Deforestation- Forests are fragile natural environments, complex biodiversity of their forests flourish on relatively thin soil. Removal of dense forest canopy protecting vital top soil can have devastating consequences as accelerate natural processes:
reduces evapourtranspiration, stores less rainwater, increased runoff,causes flash flooding, little rainfall soaks into ground so less aquifer stores and water table lower.
Urbanisation- Prevents water infiltrating into the soils only allowing 5% deep infiltration and 10% shallow from 25% deep and 25% shallow. With urbanisation increasing runoff by 45% and reducing evapourtranspiration.
Reservoirs- man-made storage reservoirs interrupt natural flows of water,delaying flows through drainage basin adding to amounts lost through evaporation. In tropics plants make evapotranspiration rates 6x higher than in open water,salinity levels in reservoir also rise as water evaporates, reservoirs also abstract water from drainage basins.
29
What is a water budget?
Balance that reflects differences between inputs and outputs in any given area, representing balance between surpluses and defecits.
30
what is the water balance equation?
P=Q+E +/- S
where,
P=precipitation, Q=runoff, E= potential evapourtranspiration , S= soil moisture and groundwater storage.
31
What happens from January to april in terms of soil moisture?
From Jan to April Precipitation (P) exceeds potential evapotranspiration (PE) resulting in a soil moisture surplus for plants, runoff and groundwater recharge.
32
What happens from April to july ?
PE exceeds P. Soil moisture is used up by plants or lost via evapouration. (soil moisture utilisation)
33
What happens in July?
Soil moisture used up, P absorbed by soil, rather than as run-off, River levels fall or dry up completely.
34
what occurs from august to September?
Deficiency of soil moisture, as store is used up. PE exceeds P, plants adapt to survive, crops need irrigation.
35
What occurs from september to october.
P exceeds PE. Soil moisture is recharged.
36
What occurs from Nov to Dec?
Soil moisture surplus, capacity reached, addition rain percolates to the water table and ground stores recharged.
37
Explain rain distribution across the months
October- P exceeds PE- recharging storage areas until full by jan. Overland flow increases until there is a water surplus raising flood risk. As temps rise and rainfall decreases in spring soils lose moisture until late august where theres a soil deficit.
38
What does field capacity mean?
Field capacity is the maximum capacity that a soil can hold. Reduced whenever E exceeds P.
39
What happens when soils saturate above the field capacity?
A water surplus- generating surface-runoff potentially causing flashflooding, especially common in dry areas, where sun baked soils cannot absorb intensive storm rain quick enough causing soil saturation.
40
What is a river regime?
Pattern of a rivers flow/discharge throughout the year.
41
What are the 2 main types of river regimes?
Simple- The river experiences a period of seasonally high discharge, followed by low discharge. Typical of rivers where inputs depend on snowmelt, glacial meltwater and monsoons. Rivers with temperate climates tned to have simple regimes. Eg. River Rhone
Complex- Where larger rivers cross several different relief and climatic zones, and therefore experience effects of differnet seasonal and climatic events. Eg. in the Ganges and missispi river. Human factors also increase complexity such as dams for energy.
42
What does a river regime show?
Differences in precipitation, temperature,evapourtranspiration and land-use characteristics of river catchment area as well as the characteristics of drainage basin itself (relief etc)
Some of the world's longest rivers cross many different climatic zones and landuses making these the most complex.
43
name and explain 3 examples of complex river regimes.
Yukon - Alaska/Canada/USA- with high flow in spring and summer and low flow in winter where precipitation is frozen. Varies majorly seasonally, with a few human influences as rural area mostly. Crossing tundra,taiga and mountain climates.
Amazon- Brazil-high flow in wetter seasons and low flow in dry seasons, moderate seasonal variability fed by andean rivers outisde the rainforest region. Affected by large dams used for irrigation and HEP. In rainforest climate with rainfall in every month with some seasons with more rain than others, High PE levels.
Murray-Darling-Australia- High flow in wet seasons with low flow in dry seasons with lots of seasonable variability, waters affected by australias major cities and farms for irrigation. seasonal sub-tropical enviroment, monsoon climate in Queenslands northern tributeries and temperate climate in south feeding DM, most of basin under a rain shadow so undergoes large periods of drought.
44
what is a storm hydrograph?
Graph showing the discharge of a river at any given point in time. A storm hydrograph shows how the tiver responds to a particular storm and displays rainfall and discharge. When rain falls only a fraction goes into the actual river, the rest is delayed as surface run off. When this water makes its way into the river, discharge increases as shown by the rising limb on the graph. Gap between peak rainfall and discharge is known as the lag time .
45
why do storm hydrographs vary?
Each storm hydrograph reflects the localised and contemporary characteristics of the drainage basin. Each change in landuse and previous period of weather will determine the height and timing of the peak .
46
How do physical characteristics affect hydrographs?
Size- larger catchments typically have higher flows but it takes longer for peak flow to occur.
Shape- circular catchments concentrate water more quicky, in long narrow catchments water takes time to reach downstream.
Drainage density- more tributeries mean water is carried more efficently, increasing concentration of flows in turn increasing peak flow
Rock permablilty- permable rocks alllow increased infliltration, percolation and ground water flow reducing runoff.
soil characteristics- permable and dry soils increase infiltration: deep soils store more water reducing surface run-off and evaporation.
Relief- Transfer water quicker with less infliltation increasing peak flow and reducing lag time.
Vegetation type and chracteristics- vegetation increases interception and evapotranspiration plus infiltration through presence of roots in soil reducing run-off and river flow.
47
How human factors affect hydrographs?
Land use- deforestation reduces vegetation cover and ploughing of land increases run-off
Urbanisation- concrete areas how a low permability and and increase overland flow via drains and surface runoff reducing lag time and increasing peak flows.
Water management( reservoirs, abstraction)- Dams and reservoirs regulate flows downstream by storing water. Abstraction lowers groundwater level and increases percolation and infiltration when it rains.
48
How is planning for housing affected by the hydrological cycle?
Planners in the UK are requires ro determine if land change will infuence flood risk.
In order to recieve permissions National Policy Framework requires
1. planners to give careful considerations to enviromental considerations.
2.Planners need to give weight to the need for development.
Planners have to show land use changes won't runoff beyod that estimated for a greenfield site.
49
What are sustainable drainage systems (SuDS) give examples.
Recently introduced to reduce runoff produced from rainfall. Examples include
>green roofs- vegetation cover planted over a waterproof membrane.
> Infiltration basins- Shallow depressions dug out to delay storm runoff and increase infiltration.
>permable pavements- to delay runoff by using gaps between pavement slabs.
>rainwater haversting- collecting rainfall from roofs for recycling.
>soak away- channel dug out to disperse surface water into the ground
>Wetlands- Retention areas with marsh/wetland vegetation
50
What is a tipping point and which country is close to reaching this point?
a tipping point involves the irreresable damage to the hydrological cycle and climatic cycles. The country which is close to reaching this tipping point is brazil's amazon.
Forests recycle half of their rainfall but the positive feedback loop of deforestation and less rainfall is reducing rainforest regenerative potential as a result of this forest ecosystems are less resilent.Thinning forests have reduced soil water storage and evaportranspiration,leading to changing weather patterns with lower precipitation.
51
What is a tipping point and which country is close to reaching this point?
a tipping point involves the irreresable damage to the hydrological cycle and climatic cycles. The country which is close to reaching this tipping point is brazil's amazon.
Forests recycle half of their rainfall but the positive feedback loop of deforestation and less rainfall is reducing rainforest regenerative potential as a result of this forest ecosystems are less resilent.Thinning forests have reduced soil water storage and evaportranspiration,leading to changing weather patterns with lower precipitation.
52
What effect does drought have on the amazon?
The amazons rainforest's capacity to absorb carbon will be reduced, regional water cycles will change and soill temperature will increase, the amazon rainforest will be replaced with savannah like grassland,more wildfires will increase the level of carbon in the atmosphere,reduced rainfall will threaten Brazils dependancy on HEP, the world will lose a major carbon sink and source of moisture.
53
What is a drought and what are the 3 classifications of drought?
Droughts are where there is a water defecit in a particular place over a period of time,compared to the average rainfall for that same period. In the UK, that's 15 consecutive days with less than 0.2mm rainfall in Libya its 2 years.
Meteorological- The degree of dryness compared to 'normal' precipitation.
Agricultural-insufficent water for crops, so that they wilt without irrigation.
Hydrological- where drainage basins suffer shortfalls
54
What are the causes of flooding?
Flash floods- when torrential rain intensity exceeds the capacity of the river to cope with the amount of water - and flooding results.In september 2016 flooding caused travel chaos in many parts of the UK as thunderstorms unleashed half a month of rain in some places.
Monsoon rainfall- Ocuurs in southeast asia between may and spetember. In july 2016 heavy monsoon rains in the Philippines led to flooding,landslides and evacuations in villages just north west of capital manila. Monsoon rains are often heavy, but in this large low pressure system brought heavier rains.
Snowmelt- Flooding can occur when the snow melts and resulting water cannot infiltrate the soil. In winter 2013 Norfolk police reported flooding caused by melting snow after wet weather caused thawing. A combination of heavy rain and rapid thawing brought flooding.
55
What exacerbates flood risk?
Farmers not only produce food but also manage and maintain the landscape however overgrazing of sheep has meant that bare slopes now replace forests degrading soil.
>trees previously absorbed and slowly released water, meandering channels slowed flow and bogs held water back
> Now bare and drier soils, straightened and dredged channels mean faster runoff, reduced stream lag times and higher peak discharge with rainwater reaching floodplains quicker- with flood plains being increasingly impermeable due to urbanisation flooding may be inevitable.
56
How can rivers be mismanaged?
In 2005 a combination of raised riverbanks, pumping stations and diversion channels carried surplus water away from built up areas in Cumbria. These hard-engineering schemes are common in cumbria, reinforced after 2005 floods. Design based on flood-return-period- statistical estimate of how a flood of a certain magnitude is likely to occur,based in past flood levels.( eg. a 1/100 flood or a 1/50 flood) however with these events becoming more common these defences are likely to be overwhelmed. In 2015 Keswick flood defences were overtopped by river greta rising to 5.9m.
57
Explain how flood risk can be mitigated?
Enviromental agency believe soft engineering is the way forward involving:
>reafforestation of upland areas the reduce surface runoff
>restoration of river channels to their natural meandering states
>restoration of flood plains to their natural absorbent states
>refusal of planning permissions to exapand developments near to rivers
58
What is The Walker cell?
circulation of air whereby the upper atmospheric air moves eastwards, and surface air moves west across the pacific causing trade winds.
59
What happens in normal years in the pacific?
Pacific winds circulate around the walker cell. Winds travel westwards bringing along warm surface water with them. Cold peruvian current that flows northwards along the west coast of SA drawn into circulation flowing westward. As it flows west, it's heated by the sun causing warm moist air to rise over indonesia, creating a low pressure area and heavy rain. Air then circulates east over the upper atmosphere, sinking into the cooler high-pressure area over western SA, giving dry conditions creating perus deserts.
60
What happens during la nina years?
Normal situation intensifies and is known as La Nina
> low pressure over western pacific becomes lower, and higher pressure over eastern pacific higher.
> As a result rainfall increases over Southeast asia and SA suffers drought
>trade winds strengthen due to increased pressure differences between the 2 areas.
60
What happens during la nina years?
Normal situation intensifies and is known as La Nina
> low pressure over western pacific becomes lower, and higher pressure over eastern pacific higher.
> As a result rainfall increases over Southeast asia and SA suffers drought
>trade winds strengthen due to increased pressure differences between the 2 areas.
61
What happens during El Nino years?
>Pressure and weather systems reverse, warmer waters develop in the eastern pacific, with temps rising up to 8Co.
>Low pressure forms, drawing westerly winds from the pacific. Warm, moist air rises, creating heavy rainfall over eastern pacific air then circulates west in the upper atmosphere.
>The decending air then creates drier conditions leading to drought in Australia and Indonesia.
62
What is ENSO and the southern ocillation index?
Change in air pressure between 'normal years' and El Nino is called the El Nino Southern Ocilation (ENSO)
> Its strength, direction and speed is called the Southern Oscillation index (SOI). Meteorolgists record air pressure at Easter island and subtract it from northern australia to calculate SOI. Sharp drop represents el nino being imminent.
63
What is the future of el nino and la nina?
>more extreme
> regions bordering pacific will see flood seasons following drought and vice versa
64
Why is there not enough water for everyone what evidence is there for a world water gap?
50% of available water is used. But rapid pop growth in areas where supply is limited together with an uneven distribution of global water supply and deterioration of water sources mean a world water gap exists.
>12% of pop consumes 85% of its water
>1.8 billion people lack clean drinking water.
>2.4billion lack adequate sanitation and 0.7
billion face water shortages
>0.8 million die from diarrhoea as a result of dirty water and 25% of people drink from a water source contaminated with faeces
>half of the worlds rivers and lakes are badly polluted.
>food supplies threatened as water shortages increase
> in water impovrished areas women spend many hours collecting water OP cost worth $24billion and denies girls eductation.
65
by 2025 how much is water demand expected to rise by?
20% globally
66
How does a country become water-stressed?
When a countrys water consumption exceeds 10% of its renewable freshwater supply meaning less than 1700 tonnes of water per person.
67
When does a country undergo water scarcity?
When water supply falls under 1000 tonnes this can threaten food supplies and reduce economic development.
68
What are the most significant water-related problems in Asia & the pacific currently?
>Asia & pacific- critical health problems with 3 of pop without clean water, 500,000 diarrhoea-related infant deaths each year in Asia.
>Water Pollution- the level of bacterial waste from human sources is 10x greater than recommended levels
>Agriculture uses 90% of freshwater withdrawals in south asia with 750 mil people unable to drink irrigation water.
>42% of chinas sewage and 45% of idustrial waste dumped into the Yangtze River each year and a billion gallons of raw sewage dumped into the ganges each day.
69
What are the key causes of water insecurity in europe?
Increasing water consumption with over half of Europe's cities overexploiting their groundwater reserves.
> Declining water quality in countries with groundwater pollution from pecidies eg. Aral sea.
70
What are the key causes of water insecurity in North America?
>aquifer depletion is increasing, due to population and urban growth
> changes in rainfall in california have led to drought
> water pollution from agricultural run-off has contaminated many ground and surface waters.
71
Causes of water insecurity in Africa?
>Predicted that 25 African countries will face either water stress of water scarcity by 2025.
> 19 of 25 countries in the world with lowest acess to clean water are in Africa.
>Lack of groundwater protection from agricultural uses
>lack of risk preparedness and mitigation
72
Causes of water insecurity in Latin America and the Caribbean?
>groundwater contamination and depletion from waste of agriculture and mining.
>poor sanitation- only 2% of sewage in latin America is treated
>Economic scarcity, with conflict over access and use of water.
73
How much has water consumption increased in proportion to population size and why?
>Global pop has increased by 4X but water consumption has increased 6X.
>Gap caused by improved living standards from increased economic development globally.
74
How has increasing urbanisation and pop lead to more pressure?
>Worlds pop growing by 80mil a year and expected to reach 9.1 bil by 2050.
>Demand for water growing twice as fast.
>6.3 billion in 2050 expected to be living in urban areas.
> led to rising middle class -->causing increase meat consumption, energy consumption, building of homes and appliances which all lead to increased water consumption and pressure.
75
How does industrialisation cause water insecurity?
>OECD predicts global water demand for manufacturing to increase by 400% from 2000 to 2050,
>Where water use isn't well regulated, pollution could increase rapidly with idustrial spillage contaminating groundwater sources.
76
How does Agriculture cuase water insecurity?
The largest consumer of water, consuming 70-90% of water. By 2050, global agriculture will need to produce 60% more food to meet demands of growing pop. Crop production causes:
>aquifers to be depleted and river flow to reduce.
>Increasing pesticide and fertlizer pollution as they seep into groundwater.
>Increased salinity of groundwater as freshwater pumped out.
77
Which areas face the highest water stress?
Middle east, china, USA, india, chile.
78
What is economic water scarcity?
The inablity to collect, purify, disribute water due to its high cost with it being charged for extortionate prices in low income countries.
79
Why does the price of water vary?
>Traditionally governments provided water as a service with price at cost.
> However with free market regulations many countries have privatised water.
> However, as a result of this costs have risen to provide profits for private companies.
> An example of where this has happened is Bolivia, in 1999 water privatised raising price so water supplies cost 20% of average income.
Aditionally in HIC water price varies with water in canada nationalised charging 80% less than germany.
>Denmark has worlds most expensive water in order to reduce water consumption by consumers.
80
What is the water poverty index and what are its 5 main components?
WPI was developed in 2002 as a means of monitoring progress and prioritising water needs in response to UN dev Goals addressing poverty and water access.
5 main components:
> WATER RESOURCES - Physical availability,
quantity and the total amount available.
>ACCESS TO WATER - distance from safe water for drinking, cooking, irrigation and industrial uses.
>HANDLING CAPACITY - Effective
management, infrastructure, and income.
>USE OF WATER- Domestic, agricultural and industrial uses
>ENVIROMENTAL INDICATORS- Ability to sustain nature and ecosystems.
Each component given a score out of 20 totalling up to 100
81
Why is global water demand increasing?
>All forms of energy generation require water as part of the production process. Thermal and HE power generation both require large quantities of water. 75% of water consumption in the UK is linked to energy generation.
> in 2050 food production will require 140% more water, specifically, agriculture will need to produce 60% more food globally this isn't sustainable more efficent uses of water needed to reduce losses and increase crop productivity.
82
How many people are without access to safe water?
in 2016 800 million people across the world lack access to safe water and sanitation with every 1$ investment into sanitation generating 7$ in economic development.
> A lack of water infrastructure in nigeria causes 335 000 children to die each year.
83
How has increasing water demand led to conflict?
Cross river boundries when economic development on either sides of a boundry is uneven, biggest conflicts when action of one country affects its neighbours water supplies.
