A larger basin with more tributaries and upland
areas bordering it will force more water down to
the river and so increase discharge
A flatter, smaller area of ground with fewer
waterways will reduce the amount of water
reaching the river and so discharge will be less
Type of Precipitation
Solid precipitation, eg snow, will settle and hold water for
periods of time, this reduces river discharge
Liquid precipitation, eg rain, will flow
much faster toward the channel so
increase discharge
More gaseous forms, eg fog/mist,
will again take longer to reach the
channel so reduce discharge
Land Use
If land has been farmed it will be more
compact so speed up surface run off and
increase river discharge
If land has been left untouched however
water will more easily infiltrate the soil so
discharge will decrease
Geology
Permeable rock will allow water to infiltrate it
and so lengthen the time before it reaches the
channel, therefore reducing river discharge
Impermeable rock however will not allow
water to percolate into it, forcing it to
remain in the soil and reach the river
faster, thus increasing discharge
Relief
Steep ground will
force water to flow
faster and reach the
channel faster,
therefore increasing
discharge
Land with a lower gradient will
make water flow slower and so
reduce discharge
Soil
Small particles making up the
soil, such as clay, will force
more surface run off and so
increase river discharge
Larger particles in the soil, such
as sand, allow water to more
easily infiltrate it and become
stored. This slows the time it will
take to reach the river channel
and so reduce discharge
Urbanisation
Land covered in impermeable and man-made surfaces
will force water into drains and the river channel much
faster and so discharge will rapidly increase
Soil allows for water to infiltrate and become
stored, this reduces river discharge
Deforestation
Land where trees have been
removed will experience reduced
interception and transpiration levels
and so discharge will increase.
Trees covering the land however will intercept
water before it becomes surface run off and so
increase the time it takes for it to reach the river
channel and so reduce discharge
Amount of precipitation
Heavy liquid precipitation will
saturate the ground quickly and
force more water into the river
channel, thus increasing discharge
Light, or solid, precipitation will
become stored easier and so
take longer to reach the channel
and so discharge will drop