water and its management

Question 1

what is the water cycle?

Answer 1

the on going cyclic movement of water within the earths atmosphere. the amount of water stays the same but the way it is distributed and stored is always changing.

Question 2

precipitation?

Answer 2

moisture that reaches the surface of the earth in the form of rain, snow, sleet, and hail

Question 3

surface run off?

Answer 3

this happens when there is more water on the surface than the land can absorb (saturated land). this is precipitation that flows over the ground surface until it reaches water bodies. this also carries eroded sediment to the water bodies

Question 4

interception?

Answer 4

when precipitation dies not reach the surface of the earth due to being obstructed by vegetation

Question 5

infiltration?

Answer 5

the flow of water from the surface to the sub surface. this can be determined by soil characteristics (porosity)

Question 6

through flow?

Answer 6

the sporadic horizontal flow of water within the soil layer until it reaches a waterbody. this is when the soil is saturated with water

Question 7

evaporation?

Answer 7

water from waterbodies is changed from water droplets to water vapor due to heat in the atmosphere

Question 8

transpiration?

Answer 8

the evaporation of water from plant leaves. stoma are cells on the leaves that control the amount of water that leaves the plant. this is the fastest way to get ground water out of the soil

Question 9

condensation?

Answer 9

water vapor that is converted back to water droplets as it rises to higher altitudes thus cooling down. the water droplets collide and then form raindrops.

Question 10

surface water?

Answer 10

water that is found on the surface of the earth, in lakes, oceans, rivers

Question 11

groundwater?

Answer 11

water that is underground in the soil and rocks

Question 12

aquifers?

Answer 12

pockets of water stored underground (or under the water table) in porous rocks like limestone

Question 13

what is the difference between confined and unconfined aquifer?

Answer 13

unconfined: partly filled with water, has a water table, and quickly recharged by precipitation
confined:fully filled with water, separated from the surface by impermeable rock, and slowly recharged

Question 14

water table?

Answer 14

boundary between water saturated and unsaturated ground. aquifers are found below the water table. precipitation and infiltration raises the water table

Question 15

artesian aquifer?

Answer 15

aquifer where the water is under pressure. water from a well sunk into an artesian aquifer will rise to the surface without the need of a pump

Question 16

potable?

Answer 16

safe to drink

Question 17

reservoirs?

Answer 17

an artificial lake used as a source of water supply, usually made behind a dam or side of a river.

Question 18

service reservoir?

Answer 18

where potable water is stored

Question 19

wells?

Answer 19

a hole dug into rock to reach the water stored in them

Question 20

rivers?

Answer 20

large natural stream of water flowing in a channel to the sea, a lake, or another river. they provide surface transfers of water to low land areas where there are many farms and villages

Question 21

permeable, semi permeable, non permeable?

Answer 21

allows all material to be passed through, allows some materials to be passed through, nothing is able to be passed through

Question 22

headwaters?

Answer 22

source of a stream of water

Question 23

what does recharge mean?

Answer 23

new water that enters an aquifer from the surface

Question 24

porosity?

Answer 24

the volume of open spaces in the soil or rock

Question 25

what is desalination?

Answer 25

the removal of salt from sea water by distillation or reverse osmosis

Question 26

what is distillation?

Answer 26

when water is boiled and released as vapor, leaving salt behind. the vapor is then condensed as liquid water which can be used
however: provision of energy (uses a lot of energy) and salt water is a source of pollution

Question 27

explain water usage on a domestic, industrial, and agricultural level?

Answer 27

domestic: cooking or drinking. washing clothes and flushing toilet, gardening, washing cars, lost in leaks
industrial: in factories for cooling, mixing and making products like dyes and paints, power generation
agricultural: irrigation, domestic animals

Question 28

water rich countries?

Answer 28

countries with plentiful fresh water supplies: may have a lot of land for rain to fall on (canada), or have many rivers (amazon). however, big areas do not ensure water as they may be surrounded by desert areas (australia)

Question 29

water poor countries?

Answer 29

countries with scarce fresh water supplies: dominated by desert countries

Question 30

water conflict?

Answer 30

conflict between countries over an access to water resources

Question 31

what is physical and economic water scarcity?

Answer 31

physical: not enough water to meet human and ecosystem demands to function effectively
economic: caused by a lack of investment in water infrastructure

Question 32

why do urban areas have higher access to drinking water?

Answer 32

it is more densely populated thus water pipes are easier and cheaper to build, wealthy people are likely to live in cities, easier to put pressure on government to make improvements

Question 33

what needs to be considered when choosing the location for a dam?

Answer 33

high precipitation, low temperature to prevent evaporation, built on strong permeable rock, built high up for HEP potential, narrow, steep sided valley. if in a wide valley there is a wider dam but it’s more expensive. away from developed areas to reduce pollution.

Question 34

advantages of dams?

Answer 34

• employment opportunities
• HEP
• flood control
• irrigation
• attract tourists
• gives water for large areas

Question 35

disadvantages of dams?

Answer 35

• relocating people
• construction costs are high and may take a long time
• maintenance costs are high
• problems for aquatic life
• deforestation
• increasing sea levels
• siltation

Question 36

how are dams sustainable and unsustainable?

Answer 36

sustainable: renewable energy (HEP), and does not burn fossil fuels
unsustainable: reservoir can be silted due to build up of material which reduces water storage capacity, dam structure under a lot of pressure can eventually fall, negative effects on environment and fish population.

Question 37

siltation?

Answer 37

build up of sediment which blocks something. can cause flooding as draining system may be ineffective

Question 38

what are the effects of dams on fish population?

Answer 38

dams block fish from moving about their natural pathways, causing interruptions in their life cycle that limit their abilities to reproduce

Question 39

what are the different ways water pollution can be caused?

Answer 39

sewage: waste mater which is rich in organic matter, allowing microbial organisms to thrive in it. needs to be treated
domestic waste: sewage from rural and urban settlements carry pathogenic microorganisms, increasing the content of nitrates and phosphates in rivers. detergents may contain toxic chemicals
industrial: use of chemicals, processing metal ores, waste heaps. gas from industrial chimneys can form acid rain.
agricultural: fertilizers, pesticides. amounts of phosphorus and nitrogen that are not absorbed by the plants may be washed from the land into ground water

Question 40

what are the impacts of water pollution:

Answer 40

• global inequalities in sewage treatment: developing countries have difficulty treating water as people aren’t educated and can’t put pressure on the government
• water born disease: caused by drinking contaminated water (typhoid, cholera)
  -biomagnification: increasing concentration of toxic substance in tissues of organisms at higher levels in the food chain
• bioaccumulation: accumulation of toxic chemical in tissue of organism
• accumulation of toxic substance in rivers: chemicals like fertilizer can reduce oxygen in lakes leading to death of marine life
  -acid rain: burning fossil fuels produce sulfur dioxide and oxides of nitrogen that are blown along long distances and react with water vapor in the atmosphere, forming acid rain

Question 41

what is the effect of acid rain on organisms in rivers?

Answer 41

• fish egg laying is reduced
• intolerable environment for aquatic life
• nutrients washed out of river
• leaching of heavy metals like aluminum which clogs fish gills and causes suffocation.