Environmental Engineering Reference
In-Depth Information
physical environment and, through their interpretation and supercomputing modelling, to
enable us to predict and manage future changes. It is readily apparent that physical
geography has important applications at the cutting edge of global environmental
research, and the development of management solutions for human socio-economic
activity in the physical environment.
CONCLUSION
This introductory chapter has reviewed the development of physical geography over the
past century. During this period the discipline has matured from the descriptive science of
its early days to one using the most sophisticated analytical techniques, based on
numerical modelling by the use of the modern computer, and based on the laboratory
analysis of the physical and chemical properties of sediments, soils and water samples.
Just as techniques of study have become more sophisticated and specialized, so physical
geographers have become more specialized too. Whilst these skills are necessary for
advancing knowledge and understanding, they carry the danger that the
reductionist
approach will mean that the
integrated
and
holist
understanding of environmental
systems will become obscured by the sheer weight of detail amassed. In short, the wood
will become lost for the trees. In this environment of research, it is important that the
systems viewpoint of the environment is emphasized, so that the implications of each
process at work, or each factor of control, are assessed as part of the whole system.
Computer models will help to do this, by providing different scenarios derived from the
modelling of whole systems. However, it is important to ensure that the fieldwork
element is not lost, and that linkages with the real world are maintained. Field
observations provided the basis for many working hypotheses generated by early physical
geographers. Many have been disproved, some reinforced, but all had the merit of
attempting real explanations about real landscapes.
Upper Wharfedale is only one small part of Earth's surface, yet it illustrates several
key features common to
environmental systems
everywhere
.
First, it has a history which
is shown in the landforms, soils and vegetation. Parts of the landscape are inherited from
previous times when conditions and processes clearly differed from those of today. We
can think of these features as
relics
of the past, but it is important to recognize that they
are not just fossils; they influence the present-day processes to a considerable degree.
Secondly, the valley is a complex system or
ecosystem
, with many dynamic linkages
between the different elements. Changes in any one factor or process work through to
affect other parts. These changes can be amplified through positive feedback or damped
down by negative feedback. Predicting what type of feedback will occur, and the
consequent changes in the whole system, is no easy matter. For example, a major present-
day concern is the attempt to predict the effects of global climatic change on
environmental systems, at all scales and in all parts of the globe. Will the new climatic
impulses lead to changes which will then stabilize by homeostasis, or will new and as yet
unpredictable systems be born?
Global climatic change is just one major part of physical geography where human
activities are involved in two-way interactions with physical environments. Human
activities clearly have the power to cause major alterations of the physical environment,
