Chapter 4: Water and its Management Flashcards
Distribution of water
Oceans
Freshwater =
ice caps and glaciers
lakes and rivers
groundwater
atmosphere
surface water
Water cycle
Evaporation
Transpiration
Condensation
Precipitation
Interception
Surface run off
Infiltration
Percolation
Groundwater flow
Sources of fresh water
Aquifers
Wells
Rivers
Reservoirs
Desalination plants
Where is water held in groundwater and how is it extracted?
Artesian wells
Aquifers
Porous Permeable
Lose structure and large air gaps
Drill pipe underground
Pumping system
What is Groundwater depletion
Water pumped faster than replenished
Water table drops
Salinity contamination
Wells dry up
Land subsidence
Increased cost and energy
Economic losses as cost > profit
Overconsumption
Droughts
Deeper wells
Types of Surface water
Streams
Lakes
Rivers
Natural springs
Reservoirs
Dams
Back flow of rivers
Explain the 2 types of Desalination
Remove dissolved salt water from seawater/ brackish water from river estuaries
Treat sewage water to make potable
Expensive
High energy and construction
distillation: water boiled and released as vapour leaving salt behind
reverse osmosis: pump water at high pressure through fine membrane
What is fresh water used for
Domestic
Agricultural
Industrial
What does fresh water usage depend on?
Level of economic development
LEDCs
most in agriculture (subsistence or commercial)
wasted water (inefficient irrigation)
small manufacturing, less demand for water
collect water from wells
lack of electricity needed
MEDCs
most in industrial and domestic
intensive farming (machines and technology)
less waste of water
industries require lots of water
high living standards
Water availability
Water rich and water poor regions
Physical water shortage = reserves exploited with high demand
Economic water shortage = people have insufficient water even though region has adequate water reserves
Conflicts when ownership and use disputed
Water quality
Potable water treated so no contamination and harmful bacteria
Non potable water extracted directly from wells etc contaminated by faeces and bacteria causing diseases and diarrhoea
Lack of access to safe water
Unsanitary facilities
Drinking water contaminated by human faeces
What is a dam
barrier across river to control flow of water
creates a reservoir upstream, artificial body of water
Uses of dams
irrigate crops
employment
renewable energy
domestic and industrial
navigation
protect from flooding
storing surplus water
protect from drought
Choice of site of dam
no earthquake or earth movements, stable
no faults or joints
hard rocks, granite
impermeable non porous
narrow cross section
less surface area
close to consumed area
sufficient annual rainfall
streams or rivers to supply to reservoir
materials available locally
avoid historical, ecological, cultural sites
avoid habitats of endangered species
Impacts of dams
Environmental:
eutrophication
habitat destruction
destruction of migration patterns
waterborne diseases
Economic:
development, improve quality of life
facilities and job opportunities
electricity
potable water
irrigation supply
Social:
resettlement
displaced people
diseases
Sources of water pollution
Domestic waste
Industrial processes
Agricultural processes
How does Domestic waste pollute water
sewage from urban or rural areas
untreated, not purified
contaminated by faeces spread pathogens
detergents damage gills of fish and mucus layers protecting fish from bacteria
Types and impact of industrial processes
mining
transport of minerals
energy
manufacture raw materials
toxic chemicals
acid rainfall
Acid rain formation
Industries burn fossil fuels
Suffer dioxide + nitrous oxide
Combine with water droplets
Form sulfuric acid and nitric acid
Increased acidity
Impacts of acid rain
damage waxy layer of plants
browning
dieback of foliage
leaches aluminium from soil to lakes
fish eggs can’t hatch
acidic food for animals
aquatic animals die
reduced biodiversity as species and lots die
Agricultural practices effect on water pollution
leakage
drainage of animal waste
run off of fertilisers
contaminated water for irrigation
poorly ploughed fields
sedimentation
soil erosion
stagnation and deoxygenation
antibiotics excreted
eutrophication
bioaccumulation
Impact of pollution
global inequalities in sewage water treatment
risk of infectious bacterial diseases
accumulation in lakes and rivers
bioaccumulation in food chains
acid rain
eutrophication
global inequalities in sewage and water treatment
LEDCs
water polluted with faeces
inadequate sanitation services
greater income = investments to improve sanitation and treatment
Managing pollution of fresh water
improved sanitation
treatment of sewage
pollution control and legislation