the hydrosphere Flashcards
what is the hydrological cycle driven by
solar power (warms water to evaporate and rise in atmosphere and energy is converted to gravitational potential, converted to kinetic as it falls towards the sea)
how does solar power drive the hydrological cycle
warms water to evaporate and rise in atmosphere and energy is converted to gravitational potential, converted to kinetic as it falls towards the sea / drives evaporation from the land and the plants that lose water by transpiration
list 3 abstractive uses of water
domestic (toilets, washing, drinking) / industrial (power stations, chemical industry, for cooling, heating, washing and steam generation) / agriculture (feeding crops and livestock, irrigation)
why is irrigation used
crops can be grown in very dry areas, so plants close their stomata to stop water loss, which stops absorption of co2 and therefore growth. to max plant growth and stop them drying out, also acts as nutrient uptake as can only be absorbed by roots if dissolved in water
name 4 non-abstractive uses of water
energy (hydroelectric power, cool condenser steam in fossil fuel, and then returned to the source) / transport (mass transport for goods, seas, canals and rivers) / recreation (sailing, canoeing, sport fishing, swimming) / wildlife conservation (wetlands or reservoirs and flooded gravel pits- important for migratory water birds, mild winters prevent water from freezing)
why are rivers a good source of water
long and accessible, short residence time so quickly self-cleaned
state 4 main features that affect the usefulness of a river
total annual water flow (river channel discharge) / flow fluctuations / level of natural contaminants / pollutants from human activities
how can rivers be used with storage reservoirs
stores water in times of surplus to be used in time of a shortage - flood prevention.
list 9 things of consideration when considering reservoir locations
topography, geology, sedimentation, catchment area, water supply, existing land use, pollution risk, estuarine barrages
why is topography important to reservoir location
needs a narrow exit and large deep basin so a relatively small dam can hold lots of water, helps financially
why is geology important to reservoir location
rock beneath reservoir must be impermeable so water can’t infiltrate into rock and be lost, must be strong enough to support weight so it doesn’t subsidies or trigger an earthquake
why is water supply important to reservoir location
rainfall or river inflow should be regular with large volume, climate shouldn’t be too hot or too dry, would cause excess evaporation losses
why is existing land use important to reservoir location
the use of land to be flooded can be important, urban areas and conservation areas would be protected and agriculture wouldn’t be so much
why is pollution risk important to reservoir location
the land uses shouldn’t pose a serious pollution risk to the water, main threats are heavy metals and agricultural pesticides
why is it bad for climate change for build up of dead vegetation in a reservoir
it would decay anaerobically and release methane, which impacts climate change
why is sedimentation important to reservoir location
soil erosion in catchment area could make the water very turbid, resulting in sedimentation, could reduce water volume
why is infrastructure important to reservoir location
building a dam, treating water, and transportation requires workers, building material and access routes, so convenient site near dam is better than a site that would supply more water but isolated
why is estuarine barrages important to reservoir location
dam across a estuary can create a freshwater lake that can be used for water supplies
give 4 environmental effects from reservoirs
habitat change (flooding destroys habitats, but also creates new ones, barrier to wildlife like salmon that migrate along the river, important in recolonising) / changes in river flow (water may be abstracted from reservoir and pumped into consumers, regulate river flow, hold back in surplus) / sedimentation (reservoirs have a low flow rate, so sediments can’t be carried down stream, important in building up river banks and coastlines / reservoir microclimate (higher specific heat capacity of water reduces temperature fluctuations, cooler summers, water provides less friction than land so more wind, greater evaporation - increases humidity)
