Theme 1 - Drainage Basin of the UK Flashcards
drainage basin?
area of land drained by a river and its tributaries
flow?
movement of water
store?
place where water is stationary within the water cycle
interception?
when rainfall does not reach the ground as it is blocked by trees, buildings and so on
infiltration?
movement of water into the soil
throughflow?
flow of water through the soil
overland flow?
flow of water across the ground surface
groundwater flow?
flow of water through rocks
transpiration?
water given off by plants
stem flow?
movement of water that has been intercepted down the stem or trunk of a plant
percolation?
movement of water from the soil into the bedrock
what happens to water as it moves through a drainage basin?
flows from one store to the next
what causes speed of water moving through a drainage basin to vary? 5
~type and quantity of rainfall
~type and quality of vegetation cover
~size and shape of the drainage basin
~steepness of slopes
~geology and soil type within the drainage basin
how does type and quantity of rainfall effect the rate of water flow? 2
~moves quicker in heavy rain
~raindrops are larger and fall in quicker so less infiltration and more surface runoff
how does type and quantity of vegetation cover effect the rate of water flow?
~more interception occurs in a woodland compared to a meadow
how does the size and shape of drainage basin effect the rate of water flow? 2
~larger basins have a larger discharge as the drain water from a large surface area of land
~round drainage basins lead to a faster movement of water into the river than elongated ones
how does steepness of slopes effect the rate of water flow?
~steeper slopes mean greater surface runoff and less infiltration
how does geology and soil type within the drainage basin effect the rate of water flow? 2
~impermeable soil or rocks led to less infiltration or groundwater flow and more surface runoff
stores of the drainage basin? 7
~oceans
~rivers and lakes
~rocks
~soil
~ground surface
~vegetation
~atmosphere
flows of the drainage basin? 10
~evaporation
~river flow
~overland flow
~throughflow
~groundwater flow
~percolation
~infiltration
~stem flow
~precipitation
~transpiration
why do river flood? 4
~climate
~geology
~vegetation
~urbanisation
how can climate cause rivers to flood?
increased amounts of rainfall
how can vegetation cause rivers to flood?
if vegetation is removed water will flow quicker as there is no blockage and more water will flow as less will be absorbed by plants
how can geology cause rivers to flood? 2
~porous rocks lave large spaces within the rock which allow water to pass through - lowers flood risk
~impermeable rocks have very small spaces not allowing water through - high risk of flood and overland flow
how can urbanisation cause rivers to flood?
expansion of towns and cities causes more surfaces to be made out of impermeable material like tarmac which reduces amount of infiltration - more overland flow so higher risk of flooding
hydrograph?
a line graph used to display the discharge of a river over a period of time
lag time?
the time between the peak rainfall and peak discharge in a river
rising limb?
the part of a hydrograph where the discharge of a river is increasing
effects of river flooding?
~road blockage
~villages cut off
~evacuation of people
~businesses lost money e.g. farmers
define hard engineering? 2
~constructing defences to control natural processes
~often large scale, expensive and relatively effective
examples of hard engineering? 4
~dams
~levees/embankments
~artificial river channels
~gabions
define soft engineering? 2
~work with the environment rather than control it
~cheaper than HE and have less impact on the environment but can be less effective
examples of soft engineering? 3
~warning systems
~restrict building on floodplains
~afforestation
land use zoning?
planning what the land is used for within a river basin so that less valuable land is closer to the river
