Physical Geography
Physical Geography is the study of the Earth’s surface features and processes. It aims to explain the geographic pattern of landforms, soils, water, vegetation, and climate by understanding the processes operating at the surface of the earth, and how these processes interact, affect and complement human activities. Physical Geography at Brock emphasizes
The field-based nature of the discipline. Students are exposed to a wide range of geographic studies including geomorphology, glacial studies, climatology, meteorology, biogeography, and environmental studies.
Geomatics
Geomatics includes scientific and technological activities which integrate various fields, including cartography, remote sensing, and geographical information systems (GIS), for the collection, analysis, and management of spatially referenced data. A number of geomatics courses are available at Brock, and students with a special interest have the option of pursuing an innovative degree program (the Concentration in Geomatics) that combines university courses with courses taught in a postgraduate program at
Niagara College. Equipped with these skills, students are well positioned to meet the growing demand for professionals who combine a geographic education with strong geomatics skills.On the Earth's surface, land, air, water, soils, plants and animals all exist together, and the physical reality of any one place is made up of all these elements. Matter and energy pass continually from one to the other.
Modern physical geography tries to interpret the natural environment as a dynamic entity. One way of demonstrating this is to use a systems approach. The study of land forms has undergone a significant change of emphasis in the last twenty years. Any understanding of land forms
Depends on an appreciation of the relative roles of climate, geology, form, process and the time as governing factors. In the first part of the twentieth century, much of geomorphological study placed its emphasis on climate, geology and time. In particular, the subject was dominated by W.M. Davis'
cycle of erosion, which stressed the evolution of land forms through time and suggested a classification of land forms based on their stage of development in the cycle. The biggest drawback with this approach was its inability to accommodate effectively the dynamics of present-day
Processes. In the 1950s and 1960s strong reaction against, Davisian ideas led to their replacement by an emphasis on process/form studies, which are concerned with an examination of the relationship between land forms and contemporary processes. The process/form approach can be usefully
placed in a systems framework.
In effect, the Davisian cycle no longer provides an adequate framework for modern geomorphology. However, this does not mean that all Davisian ideas are unsound, or that time is not an important factor in landform study.
The current emphasis on process studies has had the benefit of making geomorphology much more relevant to the rest of geography, not least in dealing with applied problems. It is more advantageous that we know, for instance, something of the discharge and sediment load of streams, than that they are 'young' or 'mature', as Davis described them.
Since the natural environment is so complex, we have to simplify it in some way in order to portray or understand it. Representations of reality are called models. We are all familiar with scaled-down models of ship or aircraft, which we can physically construct; these are examples of hardware models.
The term 'model' can also be used to describe conceptual idealizations of reality, such as a hypothesis, a law or a theory.
The definition of a model proposed by R.J. Chorley and P. Haggett is that it is 'a simplified structuring of reality which represents supposedly significant features or relationships in generalized form'. In recent years geographers have been making considerable use of models in the application and development of theory: this is a trend, which was first apparent in economic
geography in 1950s, but has now spread to physical geography. Models used in physical geography vary widely in the amount of abstraction of reality in them. Some hardware models, such as large tank
models of rivers, estuaries, and coasts, are also iconic models, closely imitating the real world in all respects but that of scale. Much more widely
used are analogue models, which represent the real world by other properties. A kaolin model of a glacier, and a map, are both analogue
models. Mathematical models in particular have become very important in geographical research since they can be used to predict changes.
Since they help us to organize and explain data, models are obviously very
useful teaching and learning aids. Models should also help to identify gaps in our knowledge and point the way to further work. Models are
simplifications of reality, and they are often very attractive; there is always
The danger that they might be substituted for and accepted as reality. Also,
since reality can be simplified in many ways, it is important that any model is considered as but one possible way of viewing the real world.
Systems (1)
With these general points in mind, we can now consider one of the more significant recent developments in physical geography, namely the widespread adoption of models in which the real world is viewed as a vast
system or set of interlocking systems. A system can be defined as a set of objects or attributes (that is, characteristics of an object, such as size or shape) linked in some relationship. We have already stressed that the
natural environment appears to operate as an entity, in which each component has connections with all the other components. It is impossible to build a model, which takes in the whole world or even a substantial part of it, so we identify various environmental sub-systems within which the
connections are fairly strong. Thus weather systems, drainage systems, ecosystems and many others can be described. In analyzing these,
the systems approach focuses attention on the whole system and the interrelationships within it, rather than on the individual parts.
Examples of systems familiar to us in everyday life include transport networks, the electricity grid system, or the domestic hot-water system of a house. These systems can be modelled symbolically by means of flow
diagrams, consisting of the objects in the system conventionally represented by symbols, usually box-shaped, and the mass or energy flows in the system represented by lines.
Systems are normally regarded as being of two types: closed, I which no energy or matter crosses the external boundaries of systems and open, in
which external factors can affect the variables within the systems. Apart from the universe, no natural system is truly closed unless we artificially
make it so for the purposes of study. However, the degree of 'openness' of systems varies considerably. The earth and its atmosphere represent a partially open system, exchanging energy with outer space, but to all intent
closed to material exchange. Other open systems exchange both mass and energy. For instance, a drainage basin receives energy and mass from
precipitation, sunlight and the elevation of the land. These inputs pass through the system, doing work on the way to emerge as outputs of heat,
water and sediment in the sea and atmosphere. A drainage system is typical of many other open systems in physical geography, which are called
process-response systems, because the flow of mass or energy (the process) causes changes of responses in form (shape or arrangement) in the system. However, where plants or animals are involved, as in a forest or a pond it is called an ecosystem.
Systems (2)
A very significant property of open systems is that elements within them attempt to adjust themselves to the flow of energy and matter through the system towards a condition of equilibrium or steady state. Thus, if we regard a hill slope as an open system, a harmonious relationship will develop over time between the gradient, the infiltration capacity and the size of the sediment particles on the slope. Similarly, in ecosystems, animal
populations will adjust closely to plant productivity. The effect of this adjustment is to balance the input of energy and material to the output.
However, equilibrium does not mean the system is static, it is performing work all the time, but the opposing forces arc balanced or fluctuating about a mean: the state can be alternatively referred to as dynamic equilibrium.
A fundamental mechanism in maintaining this state of self-regulation is that of feedback. This means that when one of the components in the system
changes, perhaps because of some external factor, this leads to a sequence of changes in the other components, which eventually affects the first component again.
The most common type of relationship is called negative feedback, whereby the circuit of changes has the result of
damping down the first change. Positive feedback, which is much rarer, occurs when the feedback loop aggravates the original change. For instance, in a glacier system, an increase in velocity leads to an increase in erosion and over deepening. The over deepening only serves to accelerate
The velocity further. But even here, checks will eventually operate; if the bedrock gradient becomes too steep, this will fundamentally alter the slip-
plane in the ice, such that erosion ceases. Positive feedback loops in nature usually operate in short bursts of destructive a activity, but in the longer term, negative and self-regulation tend to prevail.
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