Relict glacial: a landscape
created/changed by
glaciers but the glaciers
are no longer there
glacier: a large ice sheet on land
upland:
mountains/high land
lowland: low land/
on the ground
ROCK TYPES
SEDIMENTARY
Sandstone
clay
chalk
they are formed from sediments eroded and
deposited by rivers, the sea or on the sea bed.
some are resistant (eg. limestone) and some
are crumbly (eg. shale). they are compressed
for millions of years.
mainly found on lowland. rivers and coasts;
(South of UK)
IGNEOUS
found nearly everywhere in UK but mainly
Scotland and Ireland.
found on highland and relict glacials
granite
basalt
igneous rocks are formed when molten
rock cools, and becomes rock again.
METAMORPHIC
They are formed by rock that has been
transformed due to heat or pressure.
slate
marble
found mainly in the north near and in scotland
found in highland and relict glacial
the UK is split in half by the Tees-Exe line in two
areas. in the north and west of the UK, there is
more upland areas, these areas have more
resistant igneous and metamorphic rocks and
there are more faults. (slate and marble). in the
south east, it is mostly low land, which have
younger and weaker sedimentary rocks. these
erode more easily. (chalk)
PHYSCIAL PROCESSES
Tectonics
convection currents causes plates to
move, sometimes uplifting them
from the sea and creating land
Glaciation
alters river valleys, making them
wider/deeper, creating U-shaped valleys
Geology
how a rock forms in the past affecting how resistant it
is to erosion and the landscape the erosion will form.
RIVERS
RIVER SEVERN
the river severn is located in Teweksbury, Gloucestershire.
it flooded in
July 2007
because of
heavy rainfall.
the river severn flooded because Teweksbury meets the
river severn and avon which both flooded. they also built on
floodplains, had no flood defences and the heavy rainfall
runs off the imperable surfaces and into the river.
lots of homes, schools and businesses
had to close and there was an increase in
crime as abandoned homes were robbed.
they set up a free flood warning scheme and 25000 sandbags were distributed. 34
new flood defences were put in place providing protection to 30,000 homes. the
instant response was sending RAF helicopters were scrambled to help rescue people.
48,000 homes
affected.
£20,000-£30,000 repair
costs for each home.
13 deaths.
STORM HYDROPGRAPHS
when it rains, how much
rainfall reaches a river, and how
quickly, depends on the amount
and type of rainfall and what
the catchment area is like.
a hydropgraph is a way of showing how a river responds to
rainfall. it shows the relationship between rainfall (as a bar
graph) and river discharge (as a line graph).
HYDROPGRAPH FEATURES
rising limb: rising
water after rainfall
lag time: the difference between the time of the
heaviest rainfall and the peak in which the river
contains the largest amount of water (peak discharge)
Falling limb: shows the discharge of the river
falling as less water reaches the channel.
HUMAN/PHYSICAL CAUSES OF FLOODING
HUMAN
Urbanisation on the floodplain.
run off from impermeable surfaces, built by humans, into the rivers.
deforestation as trees can intercept rainfall
and when they are removed the precipitation
can reach the river channel quicker.