The natural and cultural features that exist on the Earth's surface
and the activities that occur there are collectively known in geography as phenomena.
The location and distribution of such phenomena can cause both spatial
and temporal patterns. Such patterns can be mapped. Natural features include physical
features such as mountains, lakes and rivers and so on.
Natural activities might include things such as migration of birds
like the Bar-tailed Godwit from Siberia to New Zealand.
Cultural features include population centers and highways.
Cultural activities may include activities such as trade flows
and migration.
Geographers are able to identify the various distribution
patterns that exist and explain the processes that cause them.
In geography patterns can be studied on different scales:Local, regional and global.
So when I talk about spatial variations of coastal landforms at a
beach like Muriwai, this is an example of a local scale.
If I talk about the patterns of volcanic activity in the Bay of Plenty, New Zealand,
I'm looking at patterns on a regional scale.
If I talk about the distribution patterns of the
world's population I'm talking about patterns on a global scale.
On screen here are some of the main spatial patterns studied by geographers.
This can include clustered or nucleated, dispersed or scattered, linear, peripheral,
radial and grid like patterns.
Clustered or nucleated patterns exist where
features are close together.
Patterns of dispersal exist where features are far apart.
For example, if you look at any population distribution map of this
planet you will find that there are large clusters of the world's settlements
that are located relatively close to the sea. This is because there are many
advantages of being near the sea. This includes reasons such as people like
living near beaches,
milder climates,
the presence of ports that help facilitate
international trade in ocean transport.
There are large clusters of population
in the northeastern United States,
East Asia particularly around China, Japan and Korea.
Another large cluster in South Asia with
India, Bangladesh and Pakistan
and in Western Europe
By contrast settlements are more scattered in inland areas.
This is because the interior of continents tend to have harsher climates and are difficult to access
For example, Central Australia and the Himalayas.
Another example is way cultural tourist attractions, activities and accommodation
may be clustered together through a process known as agglomeration.
This can easily be observed in New Zealand tourist towns such as Rotorua and Queenstown.
A lot of natural attractions by contrast are dispersed over a larger area
and have a more random distribution pattern.
For example the sixteen lakes in proximity to Rotorua.
This is because natural processes that form the lakes
tend to produce more random, irregular distribution patterns.
Another example of a dispersed cultural activity is where most the world's registered rugby players come from.
These figures from 2017 show that the countries with more
than 100,000 registered rugby players are dispersed around the world.
Rugby Union has high player numbers in countries as geographically far apart as
New Zealand, Japan, South Africa, Argentina and the United Kingdom.
Linear patterns are where the features are in a line.
In the cultural environment there's often a
linear pattern of development that can follow main highways.
For example, deforestation took place in close proximity to the trans Amazonian highway in Brazil.
But sometimes there are natural linear patterns too. One well known natural
linear pattern is known as the Pacific Ring of Fire.
This is a line of earthquakes and volcanic eruptions that have taken place around the Pacific Rim.
This pattern exists because earthquakes and volcanoes are associated with tectonic plate boundaries.
Many types of cultural environments can display a
regular grid like pattern. These satellite images below show a pattern of
rectangular shapes. This image shows a landscape dominated by farming.
If you closely examine this image you can see fields in a rectangular pattern
separated by shelter belts.
Likewise the urban area shown in this image clearly
displays a grid-like pattern that is typical of a cultural environment.
Whereas if I show it in an image of a natural environment features such as
native bush will be far more random because nature tends to do things more randomly.
A peripheral pattern is one where the phenomena is arranged around the edges of a feature such as a lake.
This is typical of some tourist towns that develop around a lake
or settlements on Pacific Islands that have a mountainous interior.
Radial patterns are where the phenomena spreads from a central point.
For example, Mount Taranaki in New Zealand has a pattern of streams that radiate from the centre.
Spatial patterns can be vertical as well as horizontal.
For example, one common pattern is known as altitudinal zonation
whereby vegetation types change and get shorter and sparser with altitude.
For example, in mountainous regions of New Zealand the lowlands are characterized
by tall Podocarp forest.
As one travels vertically these forests
give way to beech forests which give way to various
alpine shrubs and tussock grass.
At higher altitudes only small plants can
survive until eventually all that can be found is rock and ice.
Temporal patterns are about how things change over time.
Take for example the temporal variations that can occur with coastal processes.
At beaches around the world there are temporal patterns that are both regular and cyclic.
Every day at a given beach there is a cyclic pattern of swash and
backwash going back and forth all day, every day.
There are also cyclic patterns of tides.
For example, at a beach like Muriwai New Zealand the tide has a semi-diurnal pattern.
This means that there will be two high tides and two low tides every day.
There is also a cyclic pattern associated with the seasons.
In summer beaches tend to have a steeper profile
that is called the summer profile due to the calmer weather conditions allowing
for more deposition of sand up the beach.
In winter there are more storms.
This results in a stronger backwash that drags sediment backwards so you have a flatter beach.
That is called the winter profile.
Sometimes there will be an extreme
natural event such as a tsunami or a hurricane that will suddenly cause a lot
of erosion in a short period of time.
These events are irregular but of short duration
and eventually the regular rates of erosion and deposition will resume.
Another temporal pattern is one where there is a gradual change over a long period of time.
For example, rising sea levels due to long term changes in climate.
A fluctuating temporal pattern is one where the numbers of fluctuating but
there is an overall trend.
An example of this is the net migration flows to New Zealand.
Overall New Zealand has gained much more immigrants been emigrants
flowing out of the country.
However in times of economic crisis
there have been some years when New Zealand has had a negative net migration.