Water cycle and Water security Flashcards

Question

Convectional precipitation

Answer 1

caused when moisture evaporates and rises when heated by the sun - low pressure 3 c's

Answer 2

surface run off caused when soil is saturated

Answer 3

it is an open system an area of land that is drained by a river and its tributaries and separated from neighbouring drainage basins by a high ridge called the water shed

Answer 4

precipitation

Answer 5

evapotranspiration | runoff

Answer 6

interception storage channel storage saturated ground-water storage unsaturated ground water storage

Answer 7

``` interception stem flow overland flow infiltration throughflow percolation baseflow ```

Answer 8

inputs and outputs are cycles and there can be loose or gained to the system

Answer 9

factors that affect the whole basin

Answer 10

Inter tropical convergence zone

Answer 11

A zone of convergence at the thermal equator where the trade winds meet. A low pressure belt which migrates with the changing position of the thermal equator

Answer 12

- the thermal equator is exposed to the most intense heat from the sun over a small area - the movement of the thermal equator shifts the belt of planetary winds and pressure systems to the north and to the south annually - brings area of low pressure = rain and storms - moves to north which will experience wet weather and the area above will have hot, dry weather

Answer 13

``` pole = high pressure 60 = low pressure 30 = high pressure equator = low pressure 30 = high pressure 60 = low pressure pole = high pressure ```

Answer 14

- size of basin - drainage density - level of forest - impermeable soils and rocks - urban development - reservoirs - rural land-use - permeable soils and rocks - steep slopes - snow-capped peaks

Answer 15

large collects more precipitation and are affected by more basin-wide factors than small basins

Answer 16

low drainage density means slow movement of water across the basin area

Answer 17

more forested slopes means more interception of precipitation, which increases level of evapotranspiration and reduces surface run off

Answer 18

prevents infiltration and causes surface saturation

Answer 19

surfaces are impermeable and increase rapid run off, evaporation and interception

Answer 20

hold back the flow of water and create new surface stores

Answer 21

permits more natural processes than urban | -grasslands have higher infiltration, percolation, through-flow and evaporation than arable land

Answer 22

allow more infiltration and percolation, which in turn provide greater recharge of groundwater

Answer 23

promotes faster movement and shorter storage time than gentler slopes

Answer 24

holds water back until thaw - delayed flows

Answer 25

- types and intensity of precipitation - amount - intensity - seasonality - distribution

Answer 26

- convectional and relief - form - snow, rain or hail - snow as the entry of water into the system will create delays

Answer 27

-it will affect the amount of water in the basin ad the fluxes within it

Answer 28

the greater the intensity, the greater the likelihood of flooding

Answer 29

this is likely to result in the drainage basin system operating at different flow levels at different times of the year

Answer 30

-this is significant in large drainage basins (The Nile and The Ganges) where tributaries start in different climate zones

Answer 31

-highest precipitation found in tropics due to ITCZ and in some places during monsoon season

Answer 32

The intense solar radiation fuels the convection of warm humid air, resulting in condensation and precipitation e. g. Mawsynram, India - highest average rainfall = 11,873mm per year which is mostly during monsoon season June-Sept

Answer 33

in the Antacama Desert, Chile driest place on Earth with less than 0.2mm per year -stable area of high atmospheric pressure

Answer 34

- influenced by continentality (the distance from the sea) - continental interiors, such as the Gobi Desert in Asia or Alice Springs region in Australia - they are far from the moisture of maritime air masses

Answer 35

In mountain areas where prevailing winds are forced to rise over high altitudes

Answer 36

- vegetation intercepts rainfall - the water reaches soil via stem flow or through fall - the undergrowth may intercept some water falling - some water may return to atmosphere through evapotranspiration

Answer 37

the process whereby raindrops are prevented from falling directly on to the ground by the presence of a layer of vegetation

Answer 38

water flowing down the vegetation stems to the ground below

Answer 39

where water drips onto the ground

Answer 40

- precipitation | - vegetation

Answer 41

-when the precipitation is light and of short duration, as dry leaves and stems have the greatest water storage capacity

Answer 42

-as vegetation becomes water or rainfall intensity increases, more water will drip or flow to the ground and interception effectiveness will decrease

Answer 43

- the vegetation type and cover influence interception - denser types such as coniferous forests, intercept more rainfall than sparser deciduous forests - especially in winter, when temperate deciduous trees shed their leaves; and forests intercepts more than grass and crops

Answer 44

the movement of water vertically downwards through pores in the soil -once in the soil, water moves both vertically and laterally through. it - this is a downslope movement under the influence of gravity towards a stream or river

Answer 45

is the maximum rate at which the soil can absorb precipitation

Answer 46

- the amount of water already in the soil | - the degree of saturation

Answer 47

- precipitation intensity - vegetation cover - soil and rock type - slope gradient - water table depth - direct runoff (overland flow)

Answer 48

-infiltration-excess overland flow will occur when rainfall intensity exceeds infiltration capacity, meaning the water flows over the surface and infiltration is reduced

Answer 49

-roots help to break up the soil, increasing the infiltration rates

Answer 50

-infiltration rates will increase as porosity and permeability increases

Answer 51

-as gradient increase more water will flow over the surface, reducing infiltration

Answer 52

-as the water table rises during prolonged rainfall, the soil will become saturated, reducing infiltration

Answer 53

-water flowing over the surface of the ground

Answer 54

- occurs when water accumulates in the soil until the water table reaches or ponds on the surface, forcing further rainwater to run off surface - common where there are thin soils of moderate permeability - cavities near stream or river bank often have high moisture levels and may produce saturated overland flow early in rainstorm cycle

Answer 55

- occurs when the rainfall intensity exceeds the infiltration capacity, so the excess water flow over the ground surface - any surface runoff will quickly deliver water into river channels, increasing the risk of flooding downstream

Answer 56

the total amount of moisture removed from a drainage basin by processes of evaporation and transpiration which represents a significant output

Answer 57

the process by which liquid water is transformed into water vapour

Answer 58

the biological process by which water is drawn upwards from the soil by plants and evaporated through the minute pores (stomata)

Answer 59

the amount of evapotranspiration that could take place given unlimited supplies of water in an environment

Answer 60

the amount of evapotranspiration that takes place given the actual water availability

Answer 61

temperature wind vegetation cover soil moisture content

Answer 62

- rate of ET increases with temperature | - main source is solar radiation, so evaporation and temperature will increase with sunshine hours

Answer 63

-increase rate of evaporation by reducing the relative humidity and preventing saturation of the air

Answer 64

- transpiration will increase with increased vegetation cover which will depend on the type of vegetation and the season - vegetation with a low albedo (reflectivity) such as dark forests, will absorb more solar radiation increasing evaporation

Answer 65

- this will determine the amount of water available for transpiration - this is dependant on soil and rock permeability

Answer 66

water that has collected to flow in a rivulet, stream or river

Answer 67

-when infiltrating, water reaches permeable underlying bedrock, this will continue to move slowly downwards in to the rock by the process of percolation

Answer 68

The water will fill the spaces within the permeable or porous rock, creating groundwater storage and an aquifer - this will happen where the permeable layer lies above an impermeable rock layer so that the water can percolate further - this creates a saturated zone in the upper level called the water table - water may then move laterally as groundwater flow, if the geological structure allows

Answer 69

- permeability of the rock - linked to porosity and perviousness - angle of the rock

Answer 70

- porosity relates to the total volume of pore spaces and is greatest in coarse-grained rocks (Sandstone) - while pervious rocks such as limestone have joints and bedding planes along which water can flow - therefore percolation and groundwater flow rates will increase with porosity and perviousness - impermeable rocks such as granite, however will prevent any percolation or water movement through the ground

Answer 71

-the rate of groundwater flow will increase according to the angle of the rock strata as a steeper gradient will allow gravity to separate more effectivley

Answer 72

- over abstraction - deforestation - creation of dams and reservoirs - cloud seeding - urbanisation

Answer 73

-this is the attempt to change the type or amount of precipitation by dispersing substances into the air that serve as cloud condensation nuclei (hygroscopic nuclei)

Answer 74

-a microscopic particle in the free air, on to which water vapour may condense to form droplets

Answer 75

- new technology and research claims to have reliable results that make cloud seeding a dependable and affordable water-supply practice for many regions - however its effectiveness is still debated

Answer 76

e. g. Bejing, China - used it just before 2008 Olympic Games to create rain to clear the air of pollution e. g. Alpine Meadow, California - used to improve snow cover e. g. Texas - used to reduce the impact of drought

Answer 77

- creates impermeable surfaces that reduce infiltration and increases surface run off and through flow through artificial drains - stream and river discharges often increase rapidly as a result

Answer 78

e.g. Winchester and Maidenhead - urbanisation has increased flood risk in many towns and cities 2015 floods

Answer 79

- dams increase surface water stores and evaporation and reduce downstream river discharge - the flow rate of the river below a dam is restricted - water is held behind the dam and often released from some depth, the temp of the water below the dam is usually lower - the chemistry of the water is changed - water exiting will be higher in dissolved salts or have lower oxygen levels

Answer 80

- created to provide electricity without pollution, for flood protection and for making water accessible for agriculture and human needs - once they are built, the flow rate of the river below a dam is restricted

Answer 81

- reservoirs increase the potential for evaporation from the river - reservoir behind a dam causes the velocity if the water to drop

Answer 82

e. g. Asawm Dam, Egypt - lake Nasser behind the dam is estimated to have evaporation losses of 10 to 16 bn cubic metres every year - this represents a loss of 20-30% of the Egyptian water volume from the river nile

Answer 83

- groundwater can be abstracted from aquifers faster than it is replaced - causing reduced groundwater flow and lower water table - in some locations, reduced industrial activity or deforestation has increased groundwater storage, increasing the risk of groundwater flooding if the water table reaches the land surface

Answer 84

e. g. The Aral Sea - over 90% has disappeared due to over abstraction for irrigating cotton by Soviet Union - new diseases emerged relating to breathing - fields planted to make the Soviet Union completely self sufficient in cotton, this consumed the rivers feeding into the sea - now a pit of sand, salt and pollution - wind brings salt into nearby towns - health problems - pesticides- used to yield cotton, leached into the rivers, water pollution - health problems

Answer 85

- clearance of trees reduces evapotranspiration, but increases infiltration and surface run off - the moisture of this evapotranspiration contributes to form rainclouds which releases water back into rainforest - less moisture goes into the atmosphere when trees are cut, rainfall declines - leads to droughts - the moisture generated by rainforests travels around the world - therefore distance rainforests are important to farmers everywhere

Answer 86

e. g. Amazonia - deforestation has affected the drainage basin - lowered humidities, less precipitation - more surface run off and infiltration - more evaporation and less transpiration - more soil erosion and silt being fed into rivers

Answer 87

an underground layer of water-bearing permeable rock | -groundwater can be extracted by using water well

Answer 88

-an underground boundary between the soil surface and the area where groundwater saturates spaces between sediments and cracks in the rocks

Answer 89

- occurs when the water in soils evaporates in high temperatures daring salts from the soil to the surface - these salts are toxic to many plants and makes the land unusable - irrigation of land can cause this

Answer 90

when water is brought to land that is usually dry

Answer 91

``` precipitation = discharge + evapotranspiration + -change in storage P = Q + E + -S ```

Answer 92

precipitation is greater than potential evapotranspiration and the soil water store is full so there is a surplus of soil moisture for plant use, runoff and recharging groundwater -soil is at field capacity

Answer 93

potential evapotranspiration increases and exceeds precipitation, so there is more water evaporating from the ground surface and being transpired by plants than is falling as rain - water is drawn up from the soil by capillary action - the water is gradually used up

Answer 94

the soil water store has been used by high rates of evapotranspiration and low precipitation -plants can only survive if they are adapted to periods of drought or are irrigated

Answer 95

this occurs when potential evapotranspiration decreases so that it is lower than precipitation and the soil starts to fill up again

Answer 96

the soil is now full of water and cannot hold anymore - further rain could lead to surface run off

Answer 97

the amount of evapotranspiration that occurs as a result of temperature and vegetation as long as there is water available

Answer 98

it describes the annual variation in the discharge of a river at a particular point

Answer 99

occur when the river experiences one main factor leading to a period of high and a period of low discharge e.g. snowmelt in summer or a rainy season

Answer 100

more likely to occur in long rivers that cross more than one type of catchment which results in more than one factor influencing the pattern of discharge e.g. The Mekong river

Answer 101

e. g. The Mekong River - has a large catchment so therefore experiences different climates across the basin - varying terrain and vegetation cover adding to the complexity of the pattern - passes through mountainous relief close to its source in the Tibetan Plateau - as well as tropical areas with dense vegetation cover and monsoon climate close to its mouth

Answer 102

- size of catchment - precipitation - temperatures - vegetation cover - human intervention - geology and soil type

Answer 103

the larger the catchment area, the greater the discharge and more complex river regime

Answer 104

- amount, pattern and intensity - seasonal maximum often reflected in regime - snow reduces discharge until it melts in the summer

Answer 105

- this controls evapotranspiration which will be the greatest in the summer and reduce the discharge - glaciers melt in the summer which results in an increase in discharge

Answer 106

- this is influenced by climate and humans | - the greater the vegetation = less fluctuation in discharge as water is intercepted, utilised and evaporated

Answer 107

-dam building changes flow and can regulate it

Answer 108

- water stored in groundwater in permeable rocks steadily feeds the river as base flow all year, reducing fluctuation - impermeable will fluctuate more - decreases more in summer

Answer 109

precipitation

Answer 110

water levels rising in the river

Answer 111

time between peak rainfall and peak flow (how long the water takes to get to the river)

Answer 112

amount of water in the river (discharge, cumecs)

Answer 113

highest discharge

Answer 114

water that comes as surface run off/ overland flow

Answer 115

water levels falling in the river

Answer 116

water that came through the soil

Answer 117

water that came through the rocks

Answer 118

- short lag time - peak discharge is high - rising limb is steep - rainfall has reached the river quickly - more likely to cause flooding

Answer 119

- long lag time - peak discharge is ow - rising limb is gentle - rainfall has reached river slowly - less likely to cause flooding

Answer 120

- saturated ground - frozen ground - steep relief - high drainage density - circular drainage basin shape - more rainfall - dry soil

Answer 121

- impermeable surfaces - deforestation - urban areas

Answer 122

``` -forest area less rainfall -hot temperatures -permeable surfaces -elongated basin shape -low drainage density -flat land -dry soil ```

Answer 123

- rural area | - afforestation

Answer 124

- normally dry ground would have lots of pore spaces - therefore would encourage infiltration to occur until the soil becomes saturated again - unless the precipitation is bigger than infiltration capacity

Answer 125

- sometimes the dry ground may have experienced high evapotranspiration which may have drawn salts up through the soil via capillary action - left a salty crust on the surface, making it initially impermeable until washed away

Answer 126

- drainage basin size - drainage basin shape - drainage basin relief - soil type - rock type - drainage density - natural vegetation - land use - precipitation intensity - precipitation duration - snowfall - evapotranspiration

Answer 127

- smalls basins - water will reach the channel rapidly, as it has shorter distance to travel - large basins - water will take longer to reach the channel as it has a greater distance to travel

Answer 128

- circular basins - it will take less time for the water to reach the channel, as all the extremities are equidistant from the channel - elongated basins - water will take a long time to reach the channel from the extremities of the drainage basin

Answer 129

- steep slopes - water flows rapidly downhill and reaches the channel quickly - gentle slopes - water can infiltrate into the ground and travel slowly to the channel through the soil and rock

Answer 130

- clay soils and thin soils- clay soils have low porosity and the grains swell when they absorb water, so water infiltrates slowly. Thin soil becomes saturated quickly - sandy soils and thick soils - sandy soils have high porosity so the water can infiltrate. Deep soils allow more infiltration

Answer 131

- impermeable rocks - water cannot percolate into the rock, increasing surface run off to rivers - permeable rocks - water percolates through pore spaces and fissures into the groundwater store

Answer 132

- high drainage density - a large number of surface streams per km squared means the storm water will reach the main channel rapidly - low drainage density - a small number of surface streams per km squared means the water travels slowly through the soil and rocks to the river

Answer 133

- thin grass - intercepts little water and there is little loss by evapotranspiration so more water reaches the channel rapidly - forest and woodland - intercepts water and has high rates of evapotranspiration, so less water reaches the channel and more slowly

Answer 134

- urban - urban surfaces have more hard surfaces such as roads and drains that carry the water rapidly and directly to the river - rural - vegetated surfaces intercept water and allow infiltration so water travels slowly to the river channel

Answer 135

- high intensity - when rain falls faster than the infiltration capacity, surface run off occurs and transports the water rapidly to the channel - low intensity - water can infiltrate into the soil and then travel slowly through the soil to the river channel

Answer 136

- prolonged - the water table rises and the soil becomes saturated causing surface run off which travels to the river channel - short duration - most of the water infiltrates into the soil and travels slowly through the soil into the rocks before reaching the channel

Answer 137

- fast snowmelt - meltwater cannot infiltrate into the frozen ground, so it flows rapidly over the surface into the river channel - slow snowmelt - the ground thaws with the snow, so the meltwater can infiltrates into the soil and rocks before reaching the channel

Answer 138

- low rates - fewer losses from the drainage basin system will increase discharge into the river channel - high rates - high evapotranspiration losses will reduce discharge into the river channel

Answer 139

- they are required to determine whether any proposed developments will influence flood risk with the change in land use - The National Planning Policy Framework set out strict guidelines in England

Answer 140

decisions vary depending on how much weight I given to environmental factors versus those favouring economic development - this increases the likelihood of higher flow and faster response time as it alters the rivers flow

Answer 141

Sustainable drainage systems | -these have been introduced to reduce run off produced

Answer 142

- green roofs - infiltration basins - permeable pavements - rainwater harvesting - soak away - filter drains - detention basins - wetlands

Answer 143

vegetation cover planted over a waterproof membrane

Answer 144

shallow depressions dug out to delay run off and increase infiltration

Answer 145

to delay runoff by using gaps between pavement slabs

Answer 146

collecting rainwater from roofs to be recycled e.g. for irrigation gardens

Answer 147

a channel dug out to disperse surface water into the ground

Answer 148

trenches filled with gravel to take run off away

Answer 149

to delay storm runoff for a few hours

Answer 150

retention areas with marsh/wetland vegetation

Answer 151

- meteorological drought - agricultural drought - hydrological drought - socio/economic/famine drought

Answer 152

-occurs when long term precipitation is lower than normal (region specific)

Answer 153

insufficient soil moisture to meet the crops needs

Answer 154

deficiencies in surface and sub surface supplies | -rivers, reservoirs, lakes and groundwater - can lead to salinisation in high temps

Answer 155

- global atmospheric circulation system and the ITCZ - mid latitude blocking anticyclones - El Nino southern oscillation cycle

Answer 156

air rises leading to low pressure and rainfall - when air reaches the edge of the atmosphere, it cant go any further so it travels north and south 30 degrees and fall creating high pressure areas

Answer 157

the air becomes colder and denser and falls creating an area of high pressure and dry conditions at around 30 degrees north and south

Answer 158

air rises again at 60 degrees north and south and descends again at poles

Answer 159

- At the equator the ground is intensely heated by the sun which causes the air to rise creating an area of low pressure - as air rises, forms thick cumulonimbus clouds and air continues to rise up to upper atmosphere - air separates and starts to move both north and south. towards poles - when It reaches 30 - ccc - forms sub tropical high p - the air completes the cycle and flows back towards the equator as trade winds

Answer 160

the winds flow to the right and are called northeast trade winds -due to coriolis force and friction

Answer 161

the winds flow to the left and are called southeast trade winds -due to Coriolis force and friction

Answer 162

- the sub-tropical high pressure zone (STR sub tropical ridge) associated with the descending Hadley cell air blocks the high humidity, rain bearing air masses that arrive with the ITCZ - this is because it is very dense and stable which can cause severe drought in areas like the Sahel

Answer 163

- air falls - winds move clockwise and are gentle - high pressure area - dry weather - hot in summer and very cold in winter - very stable, not easily moved and can stay put for several weeks

Answer 164

- in mid latitudes, frontal precipitation is created in low pressure systems that form along polar front where warm tropical air rises over cold polar air - depressions move from west to east in the mid lat due to coriolis force and their track is directed by the polar front jet streams - the loops of the jet stream sometimes stabilise or even break up and this allows high pressure areas from subtropics to move northwards - anticyclones bring stale weather conditions with very little precipitation - the rain bearing depressions are pushed around them usually to north but sometimes to south -causing drought In mid latitude countries - the stability of anticyclones means they can persist and block weather systems from the west for up to two weeks - if this is repeated over the space of 2 months - normal precipitation levels are reduced and may cause drought

Answer 165

- deforestation -reduces evapotranspiration - poverty - land over-use, marginal land use - over cultivation and over grazing - development - population rise - growing affluence of a population - increases demand - climate change - over abstraction of groundwater (hydrological drought)

Answer 166

- human responses to water shortages influence water levels in reservoirs, aquifers and rivers - people have directly affected the development of droughts by abstracting water from rivers and groundwater - and by reducing the supply of water by building reservoirs and water transfers - humans are indirectly affected the developments of droughts by changing land uses and altering hydrological processes

Answer 167

- reduces vegetation cover - reduces evapotranspiration rates and thereby reducing atmospheric moisture and precipitation - the removal of vegetation also changes soil conditions through compaction and reduces organic matter and moisture retention - this reduces infiltration and increases surface run off which reduces soil moisture content and water storage

Answer 168

a cyclical sequence of events that amplifies or increases change

Answer 169

a cyclical sequence of events that damps down or neutralises the effects of a system

Answer 170

a measure of how much light that hits a surface is reflected without being absorbed

Answer 171

Abiotic | biotic

Answer 172

non-living - water - soil - rocks - atmosphere

Answer 173

living - plants - animals - fungi

Answer 174

``` nutrient cycling hydro cycle weathering food webs -these make up the functioning of the ecosystem ```

Answer 175

the biological, chemical and physical processes that take place within an ecosystem

Answer 176

is the capacity of an ecosystem to recover from disturbance or withstand ongoing pressure

Answer 177

- less river and groundwater flow into the wetlands lead to areas of open water shrinking and drying up leading to habitat loss - wetland less able to provide clean water for streams - organic soils oxidise and break down releasing carbon into atmosphere - concentrations of pollutants increase, further reducing populations of different species - less resilient species may be eliminated from the ecosystem affecting the food web - persistent dry conditions can encourage wild fires - soil moisture reduces and soil dries out, becoming vulnerable to erosion and then less able to store water in times of flood - loss of food supply for non aquatic birds are less able to find invertebrates e. g. Minsmere, Suffolk

Answer 178

- supplies water to people - drought can occur in west of the US which can help to create wild fires - caused large insect outbreaks which is deadly to millions of trees and making them more prone to fires

Answer 179

- water storage - regulation of hydrological cycle - timber production - wildlife habitat - carbon sequestration - recreational opportunities

Answer 180

- living trees take an average of 2-4 years to recover and resume normal growth rates following a period of drought - resilience to drought was lower for some species (pine) which keeps using water at a a high rate

Answer 181

- foliage loss - impairing growth - increased accumulation of pests and diseases - lashing damage to vascular tissues - impairing water transport

Answer 182

-river flooding | discharge exceeds banks full of discharge and overflows from the river

Answer 183

- surface flooding - urban flooding where the drains overflow and water comes up - water table rising to the surface creates ground saturation which results in saturated overland flow and groundwater flooding - infiltration excess flooding - rain is falling faster than infiltration capacity rate

Answer 184

a low pressure weather system which causes frontal rain as warm air from the warm front is forced to rise over cold air from the cold front

Answer 185

-they move eastwards across the Atlantic to the UK because jet-streams move them

Answer 186

- the cold front is blue with triangles, warm front is red with semi circles, black circular lines are isobars which are close together - they look like a swirling cloud

Answer 187

- steady rain can lead to saturated overland flow - intense rain can lead to infiltration excess overland flow - if the jet stream stays put over a region for a longer period of time - this place can receive more depressions than usual and therefore be at greater risk of flooding

Answer 188

- there is uncertainty - it has been suggested that the jet stream may become weaker as the Arctic warms and the tropics expand - meaning it may stay put over areas for longer period time leading to more extreme conditions e. g. Cumbria floods in 2015 Storm Desmond

Answer 189

- snow and ice responsible for flooding in mountain ranges and in higher latitudes - melting snow in late spring creates flooding in the continental interiors of Asia and America - the quick transition from winter to spring upstream causes rapid snow melting, while their lower reaches remain frozen with limited infiltration - flood water is often held up by temporary ice dams - sometimes rain falls on melting snow when a rapid thaw occurs and this combination can cause heavy flooding

Answer 190

- the rapid melting arctic is new disturbing the jet stream - the northern Hemisphere's jet stream moves from west to east in the mid latitudes between hot tropicals and cold arctic - the strongest winds are concentrated in a band - not fixed - brings storms - climate change has increased temps in tropics, when jet streams move north to Uk, experience unusually hot temps - some suggest that rapidly warming arctic is weakening the jet b y reducing the contrast between the tropical and polar air - as a result, the jet meanders more to the north and south, and these meanders can remain fixed over one location for longer

Answer 191

-the itcz moves north in the summer and south in winter and causes the Asian Monsoon season

Answer 192

describes the seasonal reversals of wind direction, caused by temperatures between the land and sea

Answer 193

- large land masses heat up rapidly, drawing humid air in from the surrounding ocean - as the moisture laden air reaches the warm. land, it rises ad the moisture condenses as rain - warmer land (low pressure and rise) - Cooler ocean (high pressure - cool air sinks)

Answer 194

- land mass becomes cooler than the surrounding ocean - cold, dry air flows. from the land out over the ocean - cooler land (high pressure - sinks) - warm ocean (low pressure -warm rises)

Answer 195

due to intense solar heating in late spring as the solar maximum moves north from the equator

Answer 196

- suggested an increase in monsoon rainfall on a seasonal mean due to warming. over the Indian Ocean which. allows more moisture to be carries to India - the variability of rainfall on shorter time scales has bigger impacts - intense heavy rainfall leads to flooding - breaks in the monsoon of a week or more lead to water shortages and agricultural drought

Answer 197

- floodplain drainage - deforestation and removal of natural vegetation - mismanagement of rivers using hard engineering - urbanisation

Answer 198

- done to provide land for agriculture or expand or urban areas - this reduces the natural storage capacity of the floodplain especially where natural wetlands are lost - land also shrinks when it is drained making it more low lying and vulnerable to flooding

Answer 199

- for agriculture and urbanisation - reduces interception and evapotranspiration - increases surface run off (saturated overland flow) and resulting in discharge reaching the river quicker (flashy graph) - increases soil erosion, resulting in higher sediment deposition and load in channels - reducing river capacity increasing flood risk e. g. deforestation in Nepal and Tibet is increasing flood risk in Bangladesh from the Ganges and Brahmaputra rivers

Answer 200

- using these structures can sometimes just transfer the flood problem elsewhere - building artificial levees increase channel capacity but precipitation is funnelled downstream instead

Answer 201

e. g. The river Mississippi - where channelisation (altering of channels, making it wider, deeper and straighter) and levees have actually increased flood risk by constricting the water and putting pressure on the levees until they burst (1993 and 2011)

Answer 202

- expansion of impermeable surfaces (roads, roofs, patios) increases surface run off into rivers via the urban drainage system - lag times are reduced as drainage systems aim to deliver water quickly to water courses so that streets don't flood

Answer 203

- structural damage to building and infrastructure (bridges) - lower property values - higher insurance premiums/refusals of insurance - loss of livelihoods (farming, factories) - drop in tourism

Answer 204

- natural moderate floods can be beneficial to wetland ecosystems by encouraging nutrient dispersal, breeding and migration - recharge of groundwater supplies - environments already degraded by human activities, flooding becomes more negative - excessive overland flow brings too much sediment and washes too many nutrients into ecosystems leading to eutrophication or pollution from chemicals which degrade ecosystems

Answer 205

- stress and grief - sewage mixing with flood water creating secondary hazard (diseases) - tropical countries - poisonous snakes

Answer 206

-spring floods are frequently intensified by rapid snow melt in the higher parts of the River Ouse catchment

Answer 207

- spring floods occurs as ice dams melt leading to catastrophic draining of glacial lakes - sometimes the flooding is exacerbated by landslides or earthquake induced dam failure

Answer 208

-glacial outburst floods are particularly frequent because of activity, which generates melt water beneath the ice sheets and acts as a trigger for ice instability and the sudden release of melt water - jokulhlaup

Answer 209

when temps soar upstream but ground remains frozen downstream, reducing infiltration

Answer 210

refers to the climate anomalies that relate to each other over large distractions -ENSO cycles have been connected with climate anomalies across the world

Answer 211

- in the ocean warm water pushes colder water downwards blocking the important upwelling of nutrient rich water from the bottom - this causes some marine life to migrate to colder waters - animals that normally feed on the sea life suffer and fisheries throughout central and South America suffered

Answer 212

-in the western US and central and South America, the warm air and moisture lead to increase storms, rainfalls, floods, loss of life and property and increase to some vector prone diseases like Malaria - even in places that it doesn't normally occur

Answer 213

-the opposite takes place, these areas suffer from droughts, wildfires, and colder oceans

Answer 214

- precipitation - run off leading to flooding - ice - Permafrost - reservoir, lake and wetland storage - snow - soil moisture stores leading to drought.

Answer 215

- will increase precipitation intensity - large amount of water will fall in a shorter length of time - length, intensity and frequency of heatwaves in Southern Europe has increased - rain instead of snow - warmer atmosphere has more water holding capacity

Answer 216

- there will be an increase in extremes - more low flows and more high flows - more intense rainfall will increase run off rates and reduce infiltration

Answer 217

- glaciers. have retreated with down wasting - thinning of a glacier due to the melting of the ice - due to rapid increase in temp and more rain/little snow - tropical altitude glaciers retreated the most (The Andes) - lowering flow from decreasing cryosphere supply

Answer 218

- physical changes of climate at high altitudes - this increases air and ocean temperatures leading to Permafrost degradation - deepening of the active layer - impacts groundwater supplies and relapses methane from thaw lakes - leads to positive feedback and accelerating change

Answer 219

- changes in wetland storage are occurring | - wetlands are affected where there are decreasing water volumes and higher temperatures

Answer 220

- length of snow cover season has decreased | - spring melt has occurred earlier

Answer 221

- where precipitation increases - soil moisture increases - warmer temperatures have led to increased drying of the land surface - increased severity of droughts - The Sahel

Answer 222

- unknown tipping point - complexity of the atmospheric system (The ENSO cycles and sunspot activity) complicates data - insufficient and incomplete data - inconsistent results of climate models - uncertainty about amounts of carbon will be released and the effect will. have on temps and rainfall - population, development, technology, new reserves

Answer 223

when present and future water supplies cannot be guaranteed

Answer 224

renewable water supplies from rivers, aquifers and lakes become very low (less than 500 m3 per person per year) Leading to widespread restrictions

Answer 225

if a country's renewable freshwater supply falls to below 1000m3 per person per year

Answer 226

if a country's renewable freshwater supply is between 1000 and 1700m3 per person per year

Answer 227

when clean water in unaffordable even if its available

Answer 228

The total amount of a country's water resources (internal and external resources) both surface water and groundwater, which is generates through the hydrological cycle

Answer 229

Ancient groundwater stored in an aquifer no longer replenished. Once used, it will not regenerate (non renewable).

Answer 230

- ENSO cycles - sub tropical ridge - Anticyclones - Climate change - Salt water encroachment

Answer 231

- the sub tropical ridge is the descending Hadley cell air | - this blocks the low pressure from ITCZ = drought and water scarcity

Answer 232

-blocking anticyclones in the northern hemisphere

Answer 233

- this is a human cause however it is impacting the hydrological cycle and therefore water scarcity - this will increase variability in precipitation patterns - changes in run off, aquifer recharge and water quality - the warmer climate will increase evaporation rates and transpiration - leading to less effective precipitation - the higher temperatures of a warmer climate and localised industrial discharges of warm waste increase many forms of pollution - warm water encourage the growth of bacteria = negative on health - the quality of water may be affected by sedimentation, nutrient enrichment, dissolved organic carbon , pathogens and pesticides

Answer 234

- occurs due to over-abstraction of water - saltwater contaminating freshwater - salt water seeps into the groundwater

Answer 235

- when water is abstracted from aquifers near the coast - more water is abstracted as well as sea level rise, salt water seeps into the ground and into the aquifer - slowly contaminating the freshwater supply

Answer 236

- increasing population and urbanisation - Improving living standards - Industrialisation - Agriculture - low development levels - climate change - Increasing population and economic growth

Answer 237

- lack of investment into making freshwater available and affordable - water stress

Answer 238

- damage to ecosystem - decline in water availability - water stress

Answer 239

- increasing demand for water - over abstraction of groundwater and surface stores - salt intrusion at the coast - water stress

Answer 240

- world population estimated to be 9.1bn in 2050 - water demand is increasing rapidly - Increased urbanisation is causing local pressure on the availability of freshwater - more than half of world pop live in urban areas - this number is predicted to be 6.3bn by 2050 - urban population in Africa and Asia

Answer 241

- rising incomes and living standards of a growing middle class in developing and emerging countries - sharp increase in water use which can be unsustainable

Answer 242

- increase meat consumption - building larger homes - Increased use of cars, appliances, energy-consumption in production and use

Answer 243

- water demand for manufacturing would increase by 400% from 2000 to 2050 - most increase in emerging and developing - polluted water has increased due to industrial spillage and poor waste management

Answer 244

- largest use of water consuming between 70-90% - 2050 - 60% more food will need to be produced to meet the demands of the growing population - Increases in agricultural demands for freshwater are unsustainable

Answer 245

- depleting aquifers and reducing river flow - degrading wildlife habitats - Increasing pesticide and fertiliser pollution as they seen into the groundwater - causing water-logging and increased salinity

Answer 246

-Aral Sea - over abstraction from surface store and disrupting the drainage basin cycle -Brazil - over abstraction from groundwater, illegal wells exacerbating the droughts of 2015 Florida - salt water intrusion

Answer 247

- supply and demand - water scarcity or large population - Infrastructure and investment - government subsidies and taxes - publicly or privately run

Answer 248

- resources - physical availability of water and its quality - access - for safe water for human use - capacity - effective water management for affordability - use - different purposes - environment - water management for sustainability

Answer 249

- providing access to clean water involves construction and maintenance of robust infrastructure systems - these services are expensive and therefore difficult for many developing nations to provide - - this is worse in area of poverty and high population density

Answer 250

-some rely on street vendors where the cost can be up to x100 more than if its was supplied to the home

Answer 251

- in the 1980s, the world bank and IMF gave loans that required many developing countries to privatise their water system - In hope that completion would reduce costs - many of these projects have been cancelled due to public pressure as the price of water became unaffordable for a large portion of the population

Answer 252

- colonial governments installed limited infrastructure to cover what were at the time small cities - massive urban growth has not outgrown the limited infrastructure and the IMF restricts governments spending on services such as water

Answer 253

Bolivia - in 1999 Bechtel took over water control in exchange for debt relief for the Bolivian government - the price immediately rose so that is cost 20% of the average income - people protested for four days and the government cancelled the contract - this impact of this is that it led to growing demand fro popular control of Bolivia's natural resources - Gas wars in 2003 and 2005

Answer 254

Canada - water is 80% cheaper than Germany - water is generally over consumed and under priced - water is publicly owned and operated - Industry use is very high

Answer 255

Denmark - freshwater prices are the highest in the world - Psychological effect on consumers - theory is that when consumers pay high costs they appreciate the scarcity and value of water - led to water being saved - water consumption in dairy farms and agriculture have fallen dramatically - some food companies are struggling and the difference in the water prices between Denmark and other countries is distorting competition within the food industry

Answer 256

- improvements in water quality improve sanitation, as well as personal and food hygiene - lower medical costs and lower days of work - Improved sanitation in school especially for girls - Improves school attendance - Improved education, improve career opportunities - leads to reduced poverty

Answer 257

- with better access to water and water quality, improves sanitation as well as personal and food hygiene - 26% reduction in diarrhoea - 65% reduction of death from diarrhoea - Improvements to health, reduces poverty as they are able to go to work

Answer 258

- bad drought -people don't have enough to eat - enough food - don't understand what they need to be eating - 90% if people don't have a toilet and half don't have access to clean drinking - agriculture employs 80% of the pop, but the country does not grow enough food to feed them - has one of the highest rates of stunting - a condition caused by chronic malnutrition during the first 1,000 days of life - children not growing physically or cognitively - poor health, impacts school and employment in later life - half of all under fives are stunted

Answer 259

-water needed for manufacturing and industry - these water supplies needs to be reliable and predictable to support financially sustainable investments in economic activities

Answer 260

- global water demand for these industrial activities are increasing - demand for manufacturing industry is expected to increase by 400% between 2000 and 2050 - mostly in emerging and developing

Answer 261

demand is increasing | -energy production is water intensive which increases stress on freshwater sources

Answer 262

- In localised areas where water use for industrial production is not well regulated or enforced, pollution would increase - Increasing economic activity with the degradation of environmental services

Answer 263

- it is critical for a families health and social dignity - access to water for economic productive uses such as agriculture or family run businesses is critical for generating income and contributing to overall economic productivity

Answer 264

-investment in improved water management and sanitation services can help reduce poverty and sustain economic growth through better health, reduced health costs, increased productivity and time savings

Answer 265

Limited realisation that there is inequality with it although it is a human right to have water

Answer 266

- half of all wetlands have been lost - these reduce floods, store water, provide direct economic benefits - forested highlands recharge aquifers and ensure clean water flow for agriculture and hydropower

Answer 267

-urban sprawl, urbanisation, over-abstraction, agriculture, deforestation, pollution all undermine an environments capacity to sustain itself

Answer 268

degreased water systems that have difficulty regulating and restoring themselves, losing resilience which accelerates water quality degradation and reduces water availability for nature and people

Answer 269

- the sea has a productive ecosystem with fish in water and invertebrates in muds - providing a food source for over 400 species - sea water falling due to evaporation exceeding inflow - causing salinity levels to increase - water demands are increasing in California so water that should reach the sea is diverted to agriculture

Answer 270

crosses more than one border

Answer 271

- dams, water pollution , water abstraction are always that upstream countries can affect water supply for downstream countries - 40% of the world's population lives within a river or lake drainage basin that extends over 2 or more countries - there are 300 transboundary aquifers

Answer 272

- 158 of the 263 transboundary water basins lack any type of cooperative management framework - there are 263 transboundary lakes which account for 60% of the global freshwater flow - developed countries have more money to invest into infrastructure and technology which therefore only benefits itself

Answer 273

- longest river in the world - goes through 11 countries - 2 major tributaries - flows through semi-arid and arid areas - increases importance of water resources due to scarcity

Answer 274

- provides for domestic use, industrial use and agricultural use - important for Sudan and Egypt - 95% of Egypt's water needs

Answer 275

- population growth - economic development - climate change

Answer 276

1929 - nile agreement between the uk and Egypt - granted significant water allocations to Sudan and Egypt making no allowance for water needs of other nile states - granted Egypt veto power over construction power and projects - upstream countries are increasingly harvesting the waters to meet the needs of their growing populations and economies

Answer 277

-nile basin initiative was made to enhance cooperation over the use of the nile water sources

Answer 278

many countries signed the cooperative framework agreement which was strongly opposed by Egypt and Sudan

Answer 279

Ethiopia announced the construction of the Grand Renaissance Dam on the Blue Nile -Egyptian livelihoods may suffer due to Higher reliance on agriculture

Answer 280

Ethiopia, Egypt and Sudan made an agreement at the new dam - Still haven't solved the border cvnttiius issues of sharing the nile

Answer 281

- $1.8bn project began in 2018 - started to generate electricity in 2015 - became the 3rd largest HEP plant in Africa - cash crops planted around the river

Answer 282

- potentially devastating to the downstream indigenous people - will prevent seasonal floods - more than 200,000 people rely on the Omo River below the river dam for subsistence farming - depend on seasonal floods to replenish the dry soils for planting - tribes people are armed to defend themselves against neighbouring tribes - there are fears that water shortages could cause violent conflict

Answer 283

-artificial floods can be released from the reservoir and irrigation projects are planned for massive sugar and cotton plantations - which will improve livelihoods of downstream people

Answer 284

- may only benefit Ethiopian state owned companies - report of human rights violations made by army against people who oppose the sugar plantains - 2011 - UNESCO's world heritage committee made the construction be halted to investigate the impact on a nearby by world heritage site (Lake Turkana) - the dam could reduce water level of lake by 10m - affecting 300,000 people, increasing salinity, threatening drinking water supply, fishing industry and the lake ecosystem

Answer 285

- arid climate with abundant rainfall - summer droughts and water shortages in the capital - forced the government to embark on the $32bn southeastern Anatolia Project (GAP)

Answer 286

- an attempt to improve incomes in Anatolia the least developed part of Turkey - development of an integrated water and energy supply system

Answer 287

-impacts Syria and Iraq because it involves damming Euphrates and Tigris Rivers which provides both countries which much of their water

Answer 288

- 55% lost through evaporation and transportation - 14% groundwater - 15% is unusable - only 16% for use

Answer 289

- construct 22 dams - 19 HEP power plants - provide irrigation fir 1.7m hectares - diversify agriculture into cash crops - help Anatolian economy to grow by 400%

Answer 290

- Turkey agreed to release water from the Ilisu Dam for Syria - Turkey intends to build the Cizre Dam to collect additional water for irrigation before the Tigris crosses the border - projections claim that by 2040 the Tigris and Euphrates Rivers will no longer reach the sea - due to dam activity and climate change

Answer 291

- many riverside towns have been flooded causing many to move to a new city (Hasankeyf) - thousands of hectares of farmland have been left uncultivated due to many channels and rivers going dry - al-Adel estimates their agricultural production as dropped by half

Answer 292

- security experts increasingly argue that resource shortages disrupt communities and create militant recruiting grounds - having military defeated ISIS, Iraq says maintaining supremacy against the Islamic group depends on providing the country with a brighter future - water is critical for this - 80% of water goes to agriculture - providing for livelihoods for more than a 1/3 of the population

Answer 293

- located around southeast Australia - home to more than 2 million people - provides for 75% of Australia's water

Answer 294

- due to an increase in water abstraction since the 1920s which is not well managed - affected by ENSO cycles, annual, seasonal and local variations in rainfall - some areas experience surpluses while others have deficits - semi desert areas in south Australia and sub tropical in Queensland

Answer 295

- agriculture - takes the most water and demand is increasing for this - irrigation - boosts profits and crops that yield the best returns - urban residents - most populated region of southeast Australia - industrial - Queensland mining industry - indigenous groups - where traditional water rights for aboriginal groups are threatened

Answer 296

- technological fixes | - attitudinal fix

Answer 297

which either involve large scale hard engineering projects or small scale innovations and appropriate technology

Answer 298

which involve people changing their behaviour towards water use to conserve water

Answer 299

- equity and social justice - public participation - futurity - environment

Answer 300

- doesn't negatively affect downstream - affordable and accessible - compensation for those negatively impacted - fair distribution of water supply

Answer 301

- involves communities in decision making and implementation - appropriate technologies used so public can access

Answer 302

- sense of security - water security - economic viability - conservation of water supply

Answer 303

- no polluting - restoration of lost and damaged ecosystems - protection of wetlands - minimising local and global environment impacts

Answer 304

- smart irrigation - price of water - virtual water - water recycling - rainwater harvesting

Answer 305

- slow supply of constant water - doesn't waste any as water is going straight to root - enables monitoring of crops - allows for control of water through technology

Answer 306

- attitudinal fix | - increasing price of water to reduce water consumption

Answer 307

- water scarce countries tries to cut out use of water by importing crops - most arid countries uses this - instead to use for agricultural use, can use for domestic

Answer 308

-used recycled sewage water for agriculture or even purifies for drinking

Answer 309

- small/large scale | - collecting rainwater for use

Answer 310

- built on the Yangtze river which flows west to east through south china - the concrete and steel dam is 2.3km long, 180m high and uses about 510,000 tons of steel.

Answer 311

- designed to control flooding on the Yangtze, improve water supply by regulating river flow, generating HEP for China's economic growth and make the river navigable - enables surplus water to build up and be diverted to northern china via the south-north transfer project

Answer 312

- power generated by 34 generators is equivalent to burning 25 million tons of crude oil - very expensive $35bn - 632m2 of land flooded to form a reservoir, displacing 1.4m people from 1500 villages - water quality effected by waste from industry, sewage and farms - decomposing vegetation in the reservoir produces methane which is a strong greenhouse gas

Answer 313

- to provide water for the Beijing region of China which has 35% of the population, 40% of the arable land but only 7% is water - 3 routes will trader 25bn m3 of water from the Yangtze River to northern China, a western route to the yellow river, an eastern route via a series of lakes and central route - due for completion in 2050 - critics suggest that with better water management, this project is not needed - rainwater harvesting, reduction in water pollution and better irrigation techniques would improve the water supply

Answer 314

- Beijing has similar water scarcity to Saudi Arabia with just 100m3 per person - boost economic development in Beijing - will reduce abstraction of groundwater (water table has dropped by 300m since the 70s)

Answer 315

- costs $70bn - submerges 370km2 of land - 345,000 will be displaced - risks draining too much water from south - could cause conflict - eastern route runs through heavy industry so likely to become polluted - water supply might be expensive for farmers to buy so they will continue to extract groundwater - river ecosystems will be affected as natural flooding regimes are changed as floodplains are dried out

Answer 316

- abstraction of water from the Mediterranean - water is either evaporated to leave behind the salts that make seawater unusable or undergoes reverse osmosis, where water is pushed through a membrane to separate it from its salts

Answer 317

- can provide a reliable supply for large settlements - 5 plants opened in 2013, aiming to provide 70% of Israel's domestic water supplies by 2020 - some plant do use solar power - produces up to 6000 tonnes of potable water per hour

Answer 318

- each plant requires its own power station in order to boil the water, contributing to carbon emissions - some do use solar power - produces vast amounts of brine that needs to be release back into sea or disposed of which can potentially harm ecosystems

Answer 319

- domestic consumers - agriculture - The UN - Environmental agency - the EU

Answer 320

The un economic commission for Europe water convention - protect and ensure the quantity, quality and sustainable use of trans-boundary water resources - helps with cooperation and resolving issues - establisehd in 1992-1996 - to restore water issues - adopt the integrated water presence management at basin scale

Answer 321

- sets out that water resources are an integral component of ecosystems natural water sources and socio-economic good - promotes co-ordinated management of water and land in a sustainable way

Answer 322

- water framework and directive and hydropower, agreed in Berlin in 2000 - set targets to restore river, lakes and canals to a good condition - requires basin wide assessments of all risks to natural environments posed by new developments

Answer 323

- checks compliance with EU framework - many will change post Brexit - manage coastal flood risk - manage waste

Answer 324

-the world bank stated that the management of basins should involve all players, with lots of cooperation to ensure every player benefits

Answer 325

- WaterAid – an international non-governmental organisation | - raises funds to improve access to safe water, sanitation and hygiene

Answer 326

Kitayita village - - 3,000 people lack access to safe water - local builders- been trained in the construction of rainwater harvesting jars -made from locally available materials (made by covering wooden mould with mud, letting it dry and then encasing it in concrete). - objective is to help the community construct on-site water supplies, close to home, removing need for people to travel long distances across difficult terrain to collect water. - jars have long life, and once constructed provides a stable water source for many years. - cheap (just £60 could pay for the construction of one jar) and effective - 1 jar can supply 7 households

Answer 327

- Public participation – appropriate tech used so public can access - Environment – collecting rain water rather than using from larger supplies - Not affecting peoples well-being

Answer 328

-Singapore attempts to boost sustainablility in many ways, e.g the whole of Singapore is a water harvesting catchment. Diversified supplies include local catchment water, recycled water and water desalinisation.

Answer 329

- Their water recycling project, known as NEWater, manages to meet up to 30% of the nation’s current water needs - it is also very sustainable, by 2060, PUB (Singapore’s National water agency) aims to increase efficiency to meet 55% of the water demand with NEWater

Answer 330

Singapore has made an agreement until 2061 to import water from Malaysia. They have also managed to cut leakages to 5%, as opposed to 20% leakages in the UK.

Answer 331

The increased water catchment for consumption can lead to less inputs into the water cycle, less evapotranspiration and soil water utilisation. Furthermore, as with any process, desalination has by-products that must be taken care of

Answer 332

- southwest of the USA - river mouth in Mexico - 7 states, 2 countries - 36 million people rely on this - most endangered river in America - provides for 5 million acres of farmland

Answer 333

- heavy pumping of groundwater has led to declining aquifers - little base flow feeding the river - Salton sea - this is sustained by water from the river -this is shrinking due to more rover water going to cities and farmland - Lake Mead water levels near Las Vegas is becoming low

Answer 334

- 20% of the world's land is under full irrigation - majority of irrigation water is pumped from aquifers - this leads to groundwater depletion - which is unsustainable

Answer 335

- 20% of freshwater extraction is for industrial and energy production - this creates large amounts of water pollution - half of water used for energy is for HEP and nuclear power stations

Answer 336

- rising living standards leads to increased per capita consumption of water - water that is polluted by a lack of sanitation is an effective medium for the breeding and transmission of diseases (cholera) - water is a productive ground for some disease vectors (mosquitoes - Malaria) - safe water is important for washing and preparing food

Answer 337

- inadequate supply of water can easily impede any water dependant aspects of economic development - costs will rise - this will encourage people to over-exploit what resources they have - this can prolong periods of drought - can lead to desertification

Water cycle and Water security Flashcards

(361 cards)