Physical Geography of Australia

This article explores the physical characteristics and geology of the Murray Darling Basin in Australia. It discusses the formation of the basin, the climate, biogeography, and soil composition in the region. The article also provides information on the changes in climate and the impact on water availability. Overall, it provides a comprehensive overview of the physical geography of Australia.

PHYSICAL GEOGRAPHY OF AUSTRALIA
Keara Pulman
S0229471
7 June 2019

GEOGRAPHY OF DARLING DOWNS (Murray Darling)
Introduction
The formation of the Murray Basin can be attributed to several changes in the geology
that took place very many years ago. It is through these changes that this particular important
water source was formed. Understanding the physical characteristics of the Murray in regard to
its formation involves considering the present state of the rivers that are found within the Basin.
In the recent state, the changes in the climate contributes quite significantly in the function of
Murry. The region is an extension or outstretch of the Darling Downs in the Southeastern part of
Australia. The changes in the climate have again affected the changes in the nature of the soil as
well as the biogeography of the Australia ecosystem (Schumacher et al 2016).
Description of the region
This particular basin covers an area which is
estimated to be more than 1 more than one
million in terms of square kilometers. This is
equivalent to almost 14% of the Australia’s
mainland. The Basin includes more than
50% of Victoria State, 75% of the Victoria,
15% of the Queensland and finally South
Eastern Part of Australia being 8%.It is
regarded to be 20th world largest basin.

Figure 1: Location of the Murray Basin (Schumacher et al 2016)
Biogeography
The significant capability of human beings to come up with species other than the native range
has increased the potentiality of the artificial species.
Desert Landscape:
The desert scene might be the most particular region out of all the various locations. What makes
the desert scene different other different biological systems, are the outstanding outrageous
temperatures. Besides there is one unique landforms dispersed all through their environment.
Nearly everybody has a vision of unlimited miles of sand, yet sand just really covers around
1/fifth of all desert surfaces. The potentiality of the artificial species in the biological system is
tested through their survival rate. This has been propelled by the progressing economic and trade
activities globally and has facilitated a rapid spread of the non-indigenous species across the
oceans and other remote parts of the world.
Despite of the small percentage of the non-indigenous species in the biological system, they
have greater impacts to the health of individuals and to the economy of Australia. At the same
time, non-indigenous species affect the ecology as they exterminate the existence of other
species as well as changing the processes within the ecosystem. Non-indigenous fish
introduction into the freshwaters has been facilitated by the improved means of transport and the
reduced obstructions in trade activities. The non-indigenous fish in the current environment has

conquered a greater part of the world and is considered to be part of the components that
contributes to the changes in the environment globally.
Climate in Murray Darling Basin.
Murray Darling Basin’s climate range is a reflection of the size, which is more than 1
million square kilometers. It has a geographical diversity that ranges from the plains which are
semi-arid to the rugged mountains. The atmosphere of the Basin is sub-tropical in various areas,
these are found in the northern sectors while the western region is basically semi-dry. While the
atmosphere of the South is mostly mild. Precipitation moves on from summer into an
overwhelming winter from north to south. The eastern side of the Basin has high normal yearly
precipitation, up to 1,500 mm and in the south, snow falls for a while each winter on the
pinnacles of the Great Dividing Range. The western side of the Basin is commonly hot and dry,
and the normal yearly precipitation is commonly less than 300 mm.
The rates of evaporation in the Basin are high, with 94% of the precipitation that falls in the
Basin being utilised by plants or vanishing from the land and surface water. The low-lying
geography of the Basin ─ warm to hot semi-bone-dry conditions in many locales ─ and the
winding and moderate streaming nature of the rivers and waterways, all culminate to produce a
high rate of evaporation. The water catchment section of the Great Dividing Range on the south-
east and southern edges of the Basin and rivers with reliable sources add up to overflow,
regardless of their littler size. Generally speaking, it is estimated that better percentage of the
runoff is contributed by the waterway system which collectively become floods (Marshall and
Alexandra 2016).

 Rainfall annually 470mm
 The potential value of the evaporation 1274mm
 The ranges of daily temperature are significantly varied.
The atmosphere is exceptionally changing in the terms of conditions from season to
season. These changes in the conditions translate into the changes in the climates.
Notwithstanding, the availability of water in any region has always ben used as a measure of the
climate change as per the records kept in various weather stations.
Changes in Climate
The precipitation or rainfall amount is usually affected by the climate. This will in turn
affect the water accessibility and availability. The chemistry of water, in terms of the quality,
will definitely change thereby leading to the occurrence of the phenomena that is unique on its
own. The obvious changes to The Murray Darling Basin means it will probably wind up drier in
the future and continue progressively because of the rising convergences of destructive
substances in the ozone layer. In this way, extraordinary dry seasons may likewise lead to
increasingly outrageous floods.
The models of climate change predict a decrease in winter precipitation for the south-
eastern area of the Basin, meaning a significant decrease in both winter and yearly runoff. For
instance, if the worldwide normal temperature increases by 1°Celcius each year, the normal
yearly precipitation in south eastern area of the Basin, will expect to decrease by between 0% ─
9%. The normal yearly runoff is required to decrease between 2 ─ 22% for the southern segment
of the SEACI area (south of 33° scope). Decreases in precipitation as well as runoff of 2°C is

dangerous and atmospheric deviation are anticipated to be roughly doubled in the future.
Anticipated changes over the northern portion of the SEACI district are less sure, with certain
models anticipating an expansion, and a diminishing in precipitation and accordingly affecting
quantity of runoff (Wheeler et al 2018).
Normal surface water accessibility over the whole Murray Darling Basin for 2030 is
anticipated to fall by 10%. The effect is anticipated to be more prominent in the southern Basin,
and these forecasts are progressively dependent in the south (Hart 2016). The recent work by
CSIRO and the Bureau of Meteorology under the Climate Change in Australia program gives
complete data about environmental change projections in different areas of the Basin. The
prospect of environmental change implies that numerous components should be viewed when
making arrangements for the future administration of water for individuals, horticulture and the
earth (Prasad et al 2017).
Geology of Murry Darling Basin.
The vast area of the Murry Darling Basin is actually coupled with a varying history of the
geology in the tectonic units which are located within the basin itself. This particular basin has
been recognized as a purely organized landscape of the common geographical features of
Australia despite the fact its geology has never been defined neatly. The current landforms which
are seen today have taken sixty million years to form. Its foundations (Basins) are estimated to
be at least hundreds of million years old (Schellart and Spakman 2015).
Gondwana
This particular Basin is formed into many tectonic units. Some are relatively small while others
are very large. The majority of the units that were formed in Australia were formed when

Australia was still considered to be part of Gondwana. This is the period before it separated from
other land masses, estimated by research at about 500 million years ago.The other developed
units which are estimated to be around 2 million years old were as a result of the splitting of
Gondwana into the eastern and western halves. Other features developed nearly 140 million
years ago. This was the period when Australia split from India.
Development of the Murry Darling Basin
In the development of its ancient characteristics, there has been the emergence of 2 saucer-like
depressions. This is regarded as a series of basins that collectively form what is commonly
referred to as The Great Artesian Basin, formed between 60 to 250 million years ago.The Murray
Ground Water Basin was formed around 60 million years ago.The Murray Ground water Basin
serves as an underline to the plains of the Riverina which has been closely associated with the
Murray as well as its tributaries. The ongoing weathering as well as erosion have resulted in the
infilling of the Basin with sedimentary rocks. This has made the ancient rocks of the basement to
continue folding, hence undergoing a metamorphosis beneath the basin as well as its perimeter.
This has led to the formation of the mountain ranges as well as the outcrops which are found in
the southern and the eastern parts of the Murry Darling Basin. The south-west part of the Murry
Darling Basin is made up of the geographical feature that is responsible for the separation of the
Southern Ocean and the Basin itself.
Earth Moving Changes
The localized activity found in the crust of the earth, is one of the more significant influences on
the soil characteristics of the groundwater quality, this translates to the modern causes of the
river as depicted by various literature sources. In the period around 3 million years ago, there

was an uplift of the Pinnaroo Block which is found near Swan Reach on the lower parts of the
River Murray. This particular lake is estimated to have area coverage of 50,000 km² ranging
from Blanchetown in South Australia to Lake Mungo (Schumacher et al 2016).
Landforms
There is an occurrence of the constructive margin where two plates diverge from each
other, thereby leading to the formation of a new crust and specific boundaries. This also occurs
when the sea floor spreads in the mid-Atlantic, where the south as well as the northern plates are
being pulled apart, especially in the case of Australia and India. Some landforms are made by the
activity of wind, water, and ice. This activity physically changes the Earth's surface via cutting
and disintegrating area surfaces, conveying and keeping soil, sand and different trash. Crustal
development and other structural action inside the Earth make landforms; mountains,
deficiencies, sinks, and volcanoes. Landform is otherwise called geography which likewise
alludes to surface highlights of a country/area/world, for example, mountains, fields, deserts,
streams, cascades, shorelines, tropical timberlands, and so on.
Topology influences any nation's monetary riches, culture, governmental issues and
social structure and Australia is not an exception. The changes in the conditions of climates as a
result of variation in the topography in any region are responsible for the non -uniform
environmental characteristics inside the Basin. The pulling apart of the plates was brought about
by the convectional currents from the Indian plate. This particular magma produced the
submarine volcanoes that sometimes lead to the development of outcrops.
The hydrologic cycle is the procedure that involves water cycle between the sky, land and
seas all determined by energy from the sun. Without the presence of the hydrologic cycle, there

would be no such thing as life. Most organisms can’t survive without water. It is through this
way that one can see how water moves on the planet. The paper’s purpose is to clarify the
importance of this cycle, and relate it to the specific locale of any habitation form in Murray
Basin. In addition it gives knowledge on how it compares impacts of geographical features, for
example in a desert scene. At the point when the precipitation falls as snow it gets collected in
the spring and summer seasons. It is after such collections that they serve as the potential sources
of water. This is important since it is more often than not occurring at the seasons with reduced
precipitation. Murray is one of a kind of regions which experience similar type of the climate.
Soil In Murray Basin
Soil is made up of gases, minerals, and organic matter together with liquids and micro-organisms
that support life. In Australia, the main type of soil is the calcarosols which is common in areas
experiencing little rainfall and semi-arid areas (Wheeler, Robinson and Bark 2018). This type of
soil assumes hard or soft carbonate fragments and has high salinity which is suitable for grain
growing. In the southern parts of Australia, calcareous takes various structures including the grey
gypsum of large texture and the brown or red soils of the old surface of the land. Type and
structure of the soil determines a particular crop that can be grown in such soil. The calcareous
soils support the growth of grains due to the present moisture at moderate levels within the soil.
Classification of soil in Australia
Generally, the classification of soil in Australia is done in a hierarchical manner based on the
purpose of the soil usually from the more general purpose to that of more specific purpose.
Based on the classification, soil in Australia has been categorized into five levels which include
sub-order, order, sub-group, great group and family(Gupta, Hughes and Powell 2018). The use of

online key in the classification of soil in Australia has made this classification system to surpass
the early systems which were used in the classification. The online key included the factual key
of the early 1960s and the handbook of the late 1960s. Based on the keys, soil in Australia was
placed into various categories including anthroposols, vertosols, calcarosols, kandosols,
podosols, hydrosols, kurosols, chromosols, sodosols, dermosols and tenosols. Other soils in
Australia are associated by strong weathering processes and this gives a clear indication of the
arid nature of the continent of Australia (Cole et al 2016).
Sub-order soil level
The categories of the soil like chromosol, vertosols, sodosols, dermosols and ferrosols of the sub-
order level determines the major color of the uppermost horizon of the sub-order soil which may
include yellow, black, red, brown and grey. Even though colors of a class may bear same
naming, the congruency may differ from the ones in the factual key and the approximation is
done by the system of color under sell by man (Grafton et al 2018). The selected sub-order from
the full order, e.g., the grey vertosol and the red kurosols show some desperate features of the
particular order level for example, the splitting of rudosols and hydrosols into further categories.
Mainly, soil is formed from the processes of weathering of materials, deposition and
accumulations of organic matter. The components of soil that results from weathering of rocks
include living organisms, mineral particles, air, water and organic matter like humus. Formation
of the soil profile is influenced by factors such as climate topography, vegetation cover and the
apparent rock material. The biogeochemical processes that results into soil formation regarding
the environmental effects is referred to as pedogenesis. The environmental changes or conditions

determine the layers of the ground or the horizons which differ from one another in terms of
texture, color, structure and chemistry (Abel et al 2016).
Conclusion
The paper has explained in-depth the impacts of the climate change to an area’s biogeography.
The soil characteristic which is dependent on weather pattern has been one of the physical
features that quickly feel the climate change. This is due to the varying rate of weathering which
is purely responsible for the formation of soil. Although the area is perceived to be undergoing
various changes in terms of the geological make up to date, the rate has been slow. The
significance of the Murray Basin including being one of the potential sources of water in the
Australia can never be undermined but remains a matter of consideration in any other meaningful
environmental research.
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