water cycle - local scale Flashcards
how may water be lost as an output in a local drainage basin system?
evapotranspiration and runoff
how is more water gained?
through precipitation
How is it an open system?
as inputs and outputs are not balanced
inputs e.g.
precipitation
outputs e.g.
evapotranspiration, stemflow
stores e.g.
groundwater, soil water, rivers, interception, surface
flows e.g.
infiltration, percolation, through flow, surface runoff, groundwater flow, streamflow, stemflow
whats meant by evapotranspiration?
the combined return of water to the atmosphere from evaporation and transpiration (plants)
what is streamflow?
water that flows through streams and into the ocean or tributaries to other rivers
what is streamflow?
what is groundwater?
water stored in the pore spaces of rock
what is meant by infiltration?
water moving from above ground into soil
percolation meaning?
water moves from the ground or soil into porous rock or rock fractures
what is the water balance?
expresses the process of water storage and transfer in a drainage system
what is the water balance formula?
precipitation = total runoff + evapotranspiration +/- storage
how is the water cycle impacted on a local scale?
deforestation, storm events, seasonal changes, agriculture, urbanisation
deforestation - impact
less interception. soil less able to store water
storm events - impact
increases runoff and water storage
seasonal changes - impact
more interception in spring; snow reduces flows; hot weather reduces precipitation
agriculture - impact
ground trampled so less infiltration; arable - ploughing increases infiltration -ditches increase runoff
urbanisation - impact
impermeable surfaces increase runoff
what does the soil water budget show??
the annual balance between inputs and outputs in the water cycle and how inputs and outputs impact soil water storage and availability
when is there a surplus of water
in the winter moths
when does it recharge soil water?
autumn
why is soil water recharged in autmn?
because the inputs of precipitation exceed the outputs of evapotranspiration
when is the water utilised?
in spring and summer when potential evapotranspiratation is at its heighests due to warmer weather
when do stores deplete?
when Evapotranspiration is greater than precipitation
what is a maximum storage of water?
field capacity
what is the water budget dependent on?
type, depth and permeability of the soil and bedrock
