1.
Natural processes operate at different rates and /or scales to create temporal
variations (changes over time) in geographic environments.
Analyse how interacting natural processes operating at different rates and /
or scales cause ONE example of temporal variations found in natural
elements and /or natural features in your geographic environment.
In my natural environment of Muriwai there are many
examples of variation. One variation is the difference between
the erosional features like a cave, and stack on the headland and
the depositional features of a beach to the north (see map). The
main reason why these variations occur is due to the operation
of wave erosion. This is a major large- scale process at Muriwai
since the large fetch and prevailing strong winds result in highenergy waves that average over 2m and can reach up to 5m in
storm conditions. This large-scale process can be broken down
into the sub-processes of wave refraction, wave erosion and
wave deposition.
When these waves approach the headland they slow down and
refract. This causes the waves to bend to fit the headland and
direct their energy onto Otakamiro point. Here the waves then
break down the rock by various types of wave erosion. One
important type of this is hydraulic action in which the pressure
differential weakens and breaks apart cracks in the rock. Over
time this develops into a cave followed by an arch and then a
stack.
At the beach a different process dominates. Here waves have
less energy so that wave deposition occurs. As sediment is
deposited a large foreshore is built up.
Since each of these sub-processes dominate in different parts of
the environment these variations result.
Overall Mark: Not Achieved
Reason: Does not answer question. Is about spatial not temporal
variations. A pity as depth is shown for spatial.
2.
Natural processes operate at different rates and /or scales to create temporal
variations (changes over time) in geographic environments.
Analyse how interacting natural processes operating at different rates and /
or scales cause ONE example of temporal variations found in natural
elements and /or natural features in your geographic environment.
Temporal variation refers to changes that occur over time. In
my natural environment there are several examples of
variation such as the differences that occur in the steeper beach
profile in summer compared to a much flatter profile in winter.
The difference in the beach profile is due to the different type of
waves that dominate in each season and to the interacting
processes of wind and wave action.
In summer waves are much smaller, often called spillers or
constructive waves. These occur because of the settled high
pressure systems at that time of the year meaning winds are
much gentler. Waves depend on winds to form as the kinetic
energy of the wind is transferred to the waves. A a result only
small waves occur at this time of the year. These waves have
little energy meaning they are unable to erode so that wave
deposition dominates. Incoming waves or swash bring in more
sediment than the weaker backwash removes so that over time a
steeper slope profile occurs.
In winter or in storm conditions the opposite occurs – deep
depressions result in strong winds that then form high waves.
These are also known as plunger or destructive waves. These
waves have a great deal of energy. Their backwash is stronger
than the swash so that more sediment is taken off the beach than
is brought onto it. Over time the foreshore is reduced leaving a
much flatter beach profile. (see diagrams).
Overall Mark: Not Achieved
Reason: Good understanding of a temporal variation and the role played
by 2 interacting processes but its not linked to a specific environment so
cannot score.
3.
Natural processes operate at different rates and /or scales to create temporal
variations (changes over time) in geographic environments.
Analyse how interacting natural processes operating at different rates and /
or scales cause ONE examples of temporal variation found in natural
elements and /or natural features in your geographic environment.
Temporal variation refers to changes that occur over time. In
my natural environment of South Muriwai one example of
variation has been to the sand dunes. After the sand dunes were
first created their shape has changed as a result of human
interaction modifying the natural processes. The original sand
dunes were created by the process of saltation. The strong SW
winds that blow over 11 knots (the critical speed required for this
process) onshore pick up the grains of titanomagnetite sand and
carry them in a bouncing fashion across the foreshore to the
backshore. Here the movement is stopped by the presence of
vegetation. The vegetation sets up a zone of zero wind velocity
that then causes the wind to deposit its load by the process of
Aeolian deposition. This is the first stage of dune formation. As
the vegetation is buried the plants grow upwards so causing
further deposition and the dune grows.
Over time this process has been affected by human action. In the
1880’s early European farmers burnt the vegetation and used
animals such as goats that depleted the dunes vegetative cover.
This meant there was no barrier to the wind so Aeolian
deposition could not occur. As a result the process of saltation
was allowed to proceed unhindered. The sand was carried
inland and the dunes decreased in size. Similar affects resulted
from the 1990’s craze of dune surfing.
This shows how the dunes have changed their shape over time
due to different human interactions on the process of saltation
and aeolian deposition.
Overall Mark: Merit
Reason: The temporal variation to the feature is related to 2 processes.
However the interaction between the processes and mention of rate
and/or scale is missing to take to an excellence level.
4.
Natural processes operate at different rates and /or scales to create temporal
variations (changes over time) in geographic environments.
Analyse how interacting natural processes operating at different rates and /
or scales cause ONE examples of temporal variation found in natural
elements and /or natural features in your geographic environment.
Temporal variation refers to changes that occur over time. In
my natural environment of South Muriwai one example of
variation has been to the sand dunes. After the sand dunes were
first created their shape has changed as a result of human
interaction. The sand dunes were originally fairly high
averaging over 8metres. However, in the time of the early
Europeans farmers introduced sheep and goats to the dunes.
These animals ate the vegetation cover so that their size was
decreased.
As a result the dunes were no longer able to protect farmland
from all the sand and a solution had to be found. Europeans
quickly discovered that if they planted the dunes their size
would be increased. In the first sand stabalisation programme in
1931 Marram grass was used that was quick growing for this
purpose and very rapidly the size of the dunes increased.
However, this solution proved too successful as the dunes grew
so quickly they eventually became unstable and collapsed.
Instead a native dune plant spinifex was used during a second
sand stabalisation programme in 1969. This proved much more
successful. Attempts have also been made to keep people from
walking over the dunes and destroying the vegetation by
providing board walks and putting up fences. As a result of
these initiatives the dunes are now more stable.
Overall Mark: Not Achieved
Reason: This is about changes to a feature over time due to human
actions not natural processes. There needs to be a link to the effects
these actions have on the natural processes that form the feature for it
to score.
5.
Natural processes operate at different rates and /or scales to create temporal
variations (changes over time) in geographic environments.
Analyse how interacting natural processes operating at different rates and /
or scales cause ONE examples of temporal variation found in natural
elements and /or natural features in your geographic environment.
Temporal variation refers to changes that occur over time. In
my natural environment of South Muriwai one example of
variation has been to the headland.
The headland was originally formed under the sea. It was only
when this was uplifted above sea level that it became subject to
change by wave processes.
Waves at Muriwai are high energy due to the long fetch of over
2,000km across the Tasman sea. When the waves approach the
headland they hit the headland and erode it. The rock crumbles
to form a notch. Over time this notch gets larger until it forms a
cave. Caves that form either side of the headland then join to
create an arch. The arch roof falls down to leave an isolated
column of rock called a stack.
This shows that over a period of time the headland has changed
shape to become a headland and a stack.
Overall Mark: Not Achieved
Reason: Many reasons. Only one process is mentioned when answer
requires 2. It also lacks any analysis that explains why wave erosion
occurs or why waves are directed onto the headland.
Unpack the Question:
Natural processes operate at different rates and /or scales to create temporal
variations (changes over time) in geographic environments.
Analyse how interacting natural processes operating at different rates and /
or scales cause TWO examples of temporal variations found in natural
elements and /or natural features in your geographic environment.
ACHIEVED
MERIT
EXCELLENCE
ONE temporal variations
is outlined as a result of
at least 2 named natural
processes
ONE temporal variations
is outlined as a result of
at least 2 named natural
processes
ONE temporal variations
is outlined as a result of
at least 2 named natural
processes
The temporal variation is
analysed saying what
and why it has changed
over time.
The temporal variation is
analysed in detail saying
what and why it has
changed over time.
The temporal variation is
analysed
comprehensively saying
what and why it has
changed over time.
At least one reference to
a case study
Several references to a
case study (names, dates
and/or statistics)
Several references to a
case study (names, dates
and/or statistics) used
throughout.
The interaction, scale
and/or rate of the
variation is explained.
Also uses
geographic terms
Based on what you have learnt have a go at writing an Excellence answer to this
question.